query: What are polymers?

title: Smart inorganic polymers

text: Smart inorganic polymers Smart inorganic polymers (SIPs) are inorganic polymers with tunable (smart) properties such as stimuli responsive physical properties (shape, conductivity, rheology). While organic polymers are often petrol-based, the backbone of SIPs is made from elements other than carbon which lessens the burden on scarce non-renewable resources or even provide alternatives to them (sustainability). Discoveries in the past decades revealed the potential of inorganic polymers for broad applicability in diverse fields. Inorganic polymers may provide greater consumer safety owing to improved properties and environmental compatibility (no need for plasticizers, intrinsically flame-retardant properties), technological and economic advancement (solid polymer electrolytes

title: Crystallization of polymers

text: of voids in the amorphous phase, drives yielding. As done in crystalline materials, particles can be added to semi-crystalline polymers to change the mechanical properties. In crystalline materials the addition of particles works to impede dislocation motion and strengthen the material. However, for many semi-crystalline polymers particle fillers weaken the material. It has been suggested that for particles to have a toughening effect in polymers the interparticle matrix ligament thickness must be smaller than a certain threshold. Crystalline polymers polypropylene and polyethylene display particle strengthening. Plastics are viscoelastic materials meaning that under applied stress, their deformation increases with time (creep).

title: Weather testing of polymers

text: Assessment (CNEP) is currently using SEPAP for industrial applications and is more generally involved in polymer and polymer failures analysis (National Centre for the Evaluation of Photoprotection) for plastic industries. Weather testing of polymers Weather testing of polymers is the controlled polymer degradation and polymer coating degradation under lab or natural conditions. Just like erosion of rocks, natural phenomena can cause degradation in polymer systems. The elements of most concern to polymers are ultraviolet radiation, moisture and humidity, high temperatures and temperature fluctuations. Polymers are used in everyday life, so it is important for scientists and polymer producers to understand

title: MBA Polymers

text: MBA Polymers MBA Polymers is a recycling company with operations globally that recovers plastics from end-of-life durable goods. MBA Polymers was founded in 1994 in the United States by Mike Biddle. The company specializes in recycling durable goods from waste streams such as electronics and auto-shredder residue. MBA Polymers raised money to develop its technology for extracting and recycling plastic from many devices. Raw material arrives at MBA Polymers’ recycling facilities either shredded or as whole parts, often from other recyclers that do not handle plastic. MBA works with manufacturers around the world to replace virgin plastics with MBA plastics

title: MBA Polymers

text: 300 million lb/year of processing capacity in Europe, China and the U.S. to turn waste into recycled plastics. MBA Polymers Ltd is working with The Plastic Bank to develop initiatives to incentivise people around the world to recycle more plastic and improve the sustainability of the plastics industry. The company experienced a factory fire in October 2000, which resulted in the death of one employee. This led to a one-year shutdown of operations. Investigations revealed that the fire was caused by dust from a toner cartridge; the company no longer accepts toner cartridges into its recycling facilities. MBA Polymers MBA

title: Laser welding of polymers

text: Laser welding of polymers Laser welding of polymers is a set of method used to join polymeric components through the use of a laser. Through the combination of joint design and the energy provided by the laser beam, several types of welds can be achieved in a variety of thermoplastic polymeric materials. Laser welding is commonly used in industry applications such as automotive headlights and instrument panels. Various types of lasers can be used in the welding of polymers. A list, and brief description, of each applicable laser type is given below. Diode lasers have a relatively low beam quality

title: Supramolecular polymers

text: Supramolecular polymers Supramolecular polymers are a kind of polymers whose monomeric units hold together via highly directional and reversible non-covalent interactions. Unlike conventional bonded polymers, supramolecular polymers engage in a variety of non-covalent interactions that define their properties. These interactions include hydrogen bonding, π-π interaction, metal coordination, and host-guest interaction. Owing to the presence of these reversible noncovalent interactions, supramolecular polymers exhibit dynamic properties such as self-healing. Owing to the nature of supramolecular polymers, the noncovalent interactions make supramolecular polymers more dynamic and reversible. Such properties enable supramolecular polymers to construct a dynamic and reversible network, which are able to

title: Supramolecular polymers

text: system. Other than applications mentioned above, other important and fascinating biomedical applications, like protein delivery, bio-imaging and diagnosis and tissue engineering, are also well developed. Supramolecular polymers Supramolecular polymers are a kind of polymers whose monomeric units hold together via highly directional and reversible non-covalent interactions. Unlike conventional bonded polymers, supramolecular polymers engage in a variety of non-covalent interactions that define their properties. These interactions include hydrogen bonding, π-π interaction, metal coordination, and host-guest interaction. Owing to the presence of these reversible noncovalent interactions, supramolecular polymers exhibit dynamic properties such as self-healing. Owing to the nature of supramolecular polymers, the

title: Ferroelectric polymers

text: Ferroelectric polymers Ferroelectric polymers are a group of crystalline polar polymers that are also ferroelectric, meaning that they maintain a permanent electric polarization that can be reversed, or switched, in an external electric field. Ferroelectric polymers, such as polyvinylidene fluoride (PVDF), are used in acoustic transducers and electromechanical actuators because of their inherent piezoelectric response, and as heat sensors because of their inherent pyroelectric response. First reported in 1971, ferroelectric polymers are polymer chains that must exhibit ferroelectric behavior, hence piezoelectric and pyroelectric behavior. A ferroelectric polymer must contain permanent electrical polarization that can be reversed repeatedly, by an opposing

title: Fire-safe polymers

text: polybenzimidazoles, and polybenzthiazoles (PBTs) are examples of polymers made with aromatic heterocycles (Figure 2). Polymers made with aromatic monomers have a tendency to condense into chars upon combustion, decreasing the amount of flammable gas that is released. Syntheses of these types of polymers generally employ prepolymers which are further reacted to form the fire-resistant polymers. Ladder polymers are a subclass of polymers made with aromatic cycles or heterocycles. Ladder polymers generally have one of two types of general structures, as shown in Figure 3.One type of ladder polymer links two polymer chains with periodic covalent bonds. In another type, the

title: Supramolecular polymers

text: water-soluble pendants, bioactive moieties as well as biomarkers, supramolecular polymers can realize various kinds of functions and applications in biomedical field. At the same time, their reversible and dynamic nature make supramolecular polymers bio-degradable, which surmounts hard-to-degrade issue of covalent polymers and makes supramolecular polymers a promising platform for biomedical applications. Being able to degrade in biological environment lowers potential toxicity of polymers to a great extent and therefore, enhances biocompatibility of supramolecular polymers. Three types self-healing materials are illustrated here: hydrogen bonding-based, metal coordination-based and π-π interaction-based self-healing supramolecular polymers. A bivalent poly(isobutylene)s (PIBs) with barbituric acid functionalized at

title: Electroactive polymers

text: polymer to compress in thickness and expand in area due to the electric field. This type of EAP typically requires a large actuation voltage to produce high electric fields (hundreds to thousands of volts), but very low electrical power consumption. Dielectric EAPs require no power to keep the actuator at a given position. Examples are electrostrictive polymers and dielectric elastomers. Ferroelectric polymers are a group of crystalline polar polymers that are also ferroelectric, meaning that they maintain a permanent electric polarization that can be reversed, or switched, in an external electric field. Ferroelectric polymers, such as polyvinylidene fluoride (PVDF), are

title: Fire-safe polymers

text: ladder polymer consists of a single chain that is double-stranded. Both types of ladder polymers exhibit good resistance to decomposition from heat because the chains do not necessarily fall apart if one covalent bond is broken. However, this makes the processing of ladder polymers difficult because they are not easily melted. These difficulties are compounded because ladder polymers are often highly insoluble. Inorganic and semiorganic polymers often employ silicon-nitrogen, boron-nitrogen, and phosphorus-nitrogen monomers. The non-burning characteristics of the inorganic components of these polymers contribute to their controlled flammability. For example, instead of forming toxic, flammable gasses in abundance, polymers prepared

title: Fire-safe polymers

text: Fire-safe polymers Fire-safe polymers are polymers that are resistant to degradation at high temperatures. There is need for fire-resistant polymers in the construction of small, enclosed spaces such as skyscrapers, boats, and airplane cabins. In these tight spaces, ability to escape in the event of a fire is compromised, increasing fire risk. In fact, some studies report that about 20% of victims of airplane crashes are killed not by the crash itself but by ensuing fires. Fire-safe polymers also find application as adhesives in aerospace materials, insulation for electronics, and in military materials such as canvas tenting. Some fire-safe polymers

title: Fire-safe polymers

text: might have been compromised. Decreased pressure also slows down decomposition of high boiling products. The polymers that are most efficient at resisting combustion are those that are synthesized as intrinsically fire-resistant. However, these types of polymers can be difficult as well as costly to synthesize. Modifying different properties of the polymers can increase their intrinsic fire-resistance; increasing rigidity or stiffness, the use of polar monomers, and/or hydrogen bonding between the polymer chains can all enhance fire-resistance. Most intrinsically fire-resistant polymers are made by incorporation of aromatic cycles or heterocycles, which lend rigidity and stability to the polymers. Polyimides, polybenzoxazoles (PBOs),

title: Fire-safe polymers

text: fire-retardant polymers was bolstered by the need for new types of synthetic polymers in World War II. The combination of a halogenated paraffin and antimony oxide was found to be successful as a fire retardant for canvas tenting. Synthesis of polymers, such as polyesters, with fire retardant monomers were also developed around this time. Incorporating flame-resistant additives into polymers became a common and relatively cheap way to reduce the flammability of polymers, while synthesizing intrinsically fire-resistant polymers has remained a more expensive alternative, although the properties of these polymers are usually more efficient at deterring combustion. Traditional polymers decompose under

title: Electroactive polymers

text: properties by very small alterations of certain physical (e.g. electric field, light, temperature) or chemical (concentrations) stimuli. Dielectric polymers are able to hold their induced displacement while activated under a DC voltage. This allows dielectric polymers to be considered for robotic applications. These types of materials also have high mechanical energy density and can be operated in air without a major decrease in performance. However, dielectric polymers require very high activation fields (>10 V/µm) that are close to the breakdown level. The activation of ionic polymers, on the other hand, requires only 1-2 volts. They however need to maintain wetness,

title: Smart inorganic polymers

text: for consumer electronics based on polymers with a low glass-transition temperature), molecular electronics with non-metal elements as improvement and replacement for metal-based conductors and electronic circuits. Recent developments in the field of Smart Inorganic Polymers have been summarized in a themed collection in the scientific journal Chemical Society Reviews. Smart inorganic polymers Smart inorganic polymers (SIPs) are inorganic polymers with tunable (smart) properties such as stimuli responsive physical properties (shape, conductivity, rheology). While organic polymers are often petrol-based, the backbone of SIPs is made from elements other than carbon which lessens the burden on scarce non-renewable resources or even provide

title: Supramolecular polymers

text: are highly desired in the field of gene therapy. On account of the dynamic and stimuli-responsive properties, supramolecular polymers offer a cogent platform to construct vectors for gene transfection. By combining ferrocene dimer with β-cyclodextrin dimer, a redox-control supramolecular polymers system has been proposed as a vector. In COS-7 cells, this supramolecular polymersic vector can release enclosed DNA upon exposing to hydrogen peroxide and achieve gene transfection. Rationally designed supramolecular polymers-based polymers can simultaneously meet the requirements of aqueous compatibility, bio-degradability, biocompatibility, stimuli-responsiveness and other strict criterion. Consequently, supramolecular polymers can be applied to the biomedical field as a robust

title: Fire-safe polymers

text: Halogen-containing materials cause even more concerns on environmental pollution. Fire-safe polymers Fire-safe polymers are polymers that are resistant to degradation at high temperatures. There is need for fire-resistant polymers in the construction of small, enclosed spaces such as skyscrapers, boats, and airplane cabins. In these tight spaces, ability to escape in the event of a fire is compromised, increasing fire risk. In fact, some studies report that about 20% of victims of airplane crashes are killed not by the crash itself but by ensuing fires. Fire-safe polymers also find application as adhesives in aerospace materials, insulation for electronics, and in

title: Crystallization of polymers

text: Crystallization of polymers Crystallization of polymers is a process associated with partial alignment of their molecular chains. These chains fold together and form ordered regions called lamellae, which compose larger spheroidal structures named spherulites. Polymers can crystallize upon cooling from the melt, mechanical stretching or solvent evaporation. Crystallization affects optical, mechanical, thermal and chemical properties of the polymer. The degree of crystallinity is estimated by different analytical methods and it typically ranges between 10 and 80%, thus crystallized polymers are often called "semi-crystalline". The properties of semi-crystalline polymers are determined not only by the degree of crystallinity, but also by

title: Electroactive polymers

text: range of possible modes of motion. Electroactive polymers Electroactive polymers, or EAPs, are polymers that exhibit a change in size or shape when stimulated by an electric field. The most common applications of this type of material are in actuators and sensors. A typical characteristic property of an EAP is that they will undergo a large amount of deformation while sustaining large forces. The majority of historic actuators are made of ceramic piezoelectric materials. While these materials are able to withstand large forces, they commonly will only deform a fraction of a percent. In the late 1990s, it has been

title: Electroactive polymers

text: Electroactive polymers Electroactive polymers, or EAPs, are polymers that exhibit a change in size or shape when stimulated by an electric field. The most common applications of this type of material are in actuators and sensors. A typical characteristic property of an EAP is that they will undergo a large amount of deformation while sustaining large forces. The majority of historic actuators are made of ceramic piezoelectric materials. While these materials are able to withstand large forces, they commonly will only deform a fraction of a percent. In the late 1990s, it has been demonstrated that some EAPs can exhibit

title: Ferroelectric polymers

text: conformation of the polymer in an electric field; or by stretching and compressing the polymer, measure generated electric fields. Pyroelectric behavior stems from the change in temperature causing electric behavior of the material. While only ferroelectric behavior is required for a ferroelectric polymer, current ferroelectric polymers exhibit pyroelectric and piezoelectric behavior. In order to have an electric polarization that can be reversed, ferroelectric polymers are often crystalline, much like other ferroelectric materials. Ferroelectric properties are derived from electrets, which are defined as a dielectric body that polarizes when an electric field and heat is applied. Ferroelectric polymers differ in that

title: Ferroelectric polymers

text: there were less than 10 to approximately 400. This large enhancement is explained by the percolation theory. These ferroelectric materials have also been used as sensors. More specifically, these types of polymers have been used for high pressure and shock compression sensors. It has been discovered that ferroelectric polymers exhibit piezoluminescence upon the application of stress. Piezoluminescence has been looked for in materials that are piezoelectric. These types of polymers have played a role in biomedical and robotic applications and liquid crystalline polymers. In 1974, R.B. Meyer predicted ferroelectricity in chiral smectic liquid crystals by pure symmetry conditions. Shortly after,

title: Supramolecular polymers

text: torn. Chain-folding polyimide and pyrenyl-end-capped chains give rise to supramolecular networks. With the excellent nature in biodegradation and biocompatibility, supramolecular polymers show great potential in the development of drug delivery, gene transfection and other biomedical applications. Multiple cellular stimuli could induce responses in supramolecular polymers. The dynamic molecular skeletons of supramolecular polymers can be depolymerized when exposing to the external stimuli like pH "in vivo". On the basis of this property, supramolecular polymers are capable of being a drug carrier. Making use of hydrogen bonding between nucleobases to induce self-assemble into pH-sensitive spherical micelles. Effective and low-toxic nonviral cationic vectors

title: Electroactive polymers

text: though some polymers have been developed as self-contained encapsulated activators which allows their use in dry environments. Ionic polymers also have a low electromechanical coupling. They are however ideal for bio-mimetic devices. While there are many different ways electroactive polymers can be characterized, only three will be addressed here: stress–strain curve, dynamic mechanical thermal analysis, and dielectric thermal analysis. Stress strain curves provide information about the polymer's mechanical properties such as the brittleness, elasticity and yield strength of the polymer. This is done by providing a force to the polymer at a uniform rate and measuring the deformation that results.

title: PH-sensitive polymers

text: can be used to release of insulin. PH-sensitive polymers pH sensitive or pH responsive polymers are materials which will respond to the changes in the pH of the surrounding medium by varying their dimensions. Materials may swell, collapse, or change depending on the pH of their environment. This behavior is exhibited due to the presence of certain functional groups in the polymer chain. pH-sensitive materials can be either acidic or basic, responding to either basic or acidic pH values. These polymers can be designed with many different architectures for different applications. Key uses of pH sensitive polymers are controlled drug

title: PH-sensitive polymers

text: PH-sensitive polymers pH sensitive or pH responsive polymers are materials which will respond to the changes in the pH of the surrounding medium by varying their dimensions. Materials may swell, collapse, or change depending on the pH of their environment. This behavior is exhibited due to the presence of certain functional groups in the polymer chain. pH-sensitive materials can be either acidic or basic, responding to either basic or acidic pH values. These polymers can be designed with many different architectures for different applications. Key uses of pH sensitive polymers are controlled drug delivery systems, biomimetics, micromechanical systems, separation processes,

title: Heparin mimicking polymers

text: Heparin mimicking polymers Heparin Mimicking Polymers are synthetic compounds that possess similar characteristics to heparin, that is it can be used clinically as an anticoagulant. These compounds like heparin possess a negative charge density that allows it to interact and inhibit the coagulation process. Glucose or mannose-contain n-alkyl urea peptoid oligomer, glucose modified diamine with pedant monosaccharides are examples of heparin mimicking polymers. Heparin mimicking polymers can also be used to create biomaterials for surgical application such as pacemakers, stents, etc. Heparin is widely used as a clinical anticoagulant however, it possesses drawbacks creating a need for synthetic heparin mimicking

title: Fracture in polymers

text: field as many industries transition to implementing polymers in many critical structural applications. As industries make the shift to implementing polymeric materials, a greater understanding of failure mechanisms for these polymers is needed . Polymers may exhibit some inherently different behaviors than metals when cracks are subject to loading. This is largely attributed to their tough and ductile mechanical properties. Microstructurally, metals contain grain boundaries, crystallographic planes and dislocations while polymers are made up of long molecular chains. In the same instance that fracture in metals involves breaking bonds, the covalent and van der Waals bonds need to be broken

title: PH-sensitive polymers

text: form micelles, as will star polymers and branched polymers. However, star and branched polymers can form rod or worm-shaped micelles rather than the typical spheres. Brush polymers are usually used for modifying surfaces since their structure doesn’t allow them to form a larger structure like a micelle. pH sensitive polymers can be synthesized using several common polymerization methods. Functional groups may need to be protected so that they do not react depending on the type of polymerization. The masking can be remooved after polymerization so that they regain their pH-sensitive functionality. Living polymerization is often used for making pH sensitive

title: Crystallization of polymers

text: is opaque. Crystallinity also affects dyeing of polymers: crystalline polymers are more difficult to stain than amorphous ones because the dye molecules penetrate much easier through amorphous regions. Crystallization of polymers Crystallization of polymers is a process associated with partial alignment of their molecular chains. These chains fold together and form ordered regions called lamellae, which compose larger spheroidal structures named spherulites. Polymers can crystallize upon cooling from the melt, mechanical stretching or solvent evaporation. Crystallization affects optical, mechanical, thermal and chemical properties of the polymer. The degree of crystallinity is estimated by different analytical methods and it typically ranges

title: Fire-safe polymers

text: produce non-combustible products, or add chemicals that would remove fire-propagating radicals (H and OH), to name a few. These specific chemicals can be added into the polymer molecules permanently (see Intrinsically Fire-Resistant Polymers) or as additives and fillers (see Flame-Retardant Additives and Fillers). Oxygen catalyzes the pyrolysis of polymers at low concentration and initiates oxidation at high concentration. Transition concentrations are different for different polymers. (e.g., polypropylene, between 5% and 15%). Additionally, polymers exhibit a structural-dependent relationship with oxygen. Some structures are intrinsically more sensitive to decomposition upon reaction with oxygen. The amount of access that oxygen has to the

title: Depolymerizable polymers

text: Depolymerizable polymers Depolymerizable polymers or Low-Ceiling Temperature Polymers refer to polymeric materials that can undergo depolymerization to revert the materials to their monomers at relatively low temperatures, such as room temperature. For example, the ceiling temperature T for formaldehyde is 119 °C, and that for acetaldehyde is -39 °C. Unlike stable polymers such as PVCs that have high thermal stability, depolymerizable polymers and closely related self-immolative polymers can be triggered by stimuli to break fast under moderate to low temperatures. The first type of polymers, poly (olefin sulfone), was reported by Snow and Frey in 1943. It was further confirmed

title: Crystallization of polymers

text: amorphous and are classified as semicrystalline. Examples of semi-crystalline polymers are linear polyethylene (PE), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE) or isotactic polypropylene (PP). Whether or not polymers can crystallize depends on their molecular structure – presence of straight chains with regularly spaced side groups facilitates crystallization. For example, crystallization occurs much easier in isotactic than in the atactic polypropylene form. Atactic polymers crystallize when the side groups are very small, as in polyvinyl and don't crystallize in case of large substituents like in rubber or silicones. Nucleation starts with small, nanometer-sized areas where as a result of heat motion some

title: Crystallization of polymers

text: the size and orientation of the molecular chains. Polymers are composed of long molecular chains which form irregular, entangled coils in the melt. Some polymers retain such a disordered structure upon freezing and thus convert into amorphous solids. In other polymers, the chains rearrange upon freezing and form partly ordered regions with a typical size of the order 1 micrometer. Although it would be energetically favorable for the polymer chains to align parallel, such alignment is hindered by the entanglement. Therefore, within the ordered regions, the polymer chains are both aligned and folded. Those regions are therefore neither crystalline nor

title: PH-sensitive polymers

text: for specific applications. Polymers can be designed to respond to more than one external stimulus, such as pH and temperature. Often, these polymers are structured as a copolymer where each polymer displays one type of response. pH sensitive polymers have been created with linear block copolymer, star, branched, dendrimer, brush, and comb architectures. Polymers of different architectures will self-assemble into different structures. This self-assembly can occur due to the nature of the polymer and the solvent, or due to a change in pH. pH changes can also cause the larger structure to swell or deswell. For example, block copolymers often

title: PH-sensitive polymers

text: and surface functionalization. pH sensitive polymers can be broken into two categories: those with acidic groups (such as -COOH and -SOH) and those with basic groups (-NH). The mechanism of response is the same for both, only the stimulus varies. The general form of the polymer is a backbone with functional "pendant groups" that hang off of it. When these functional groups become ionized in certain pH levels, they acquire a charge (+/-). Repulsions between like charges cause the polymers to change shape. Polyacids, also known as anionic polymers, are polymers that have acidic groups. Examples of acidic functional groups

title: Ferroelectric polymers

text: solvent formed films shows that the VDF copolymers(consisting of 70% vinylidene fluoride (VDF) and 30% trifluoroethylene (TrFE)) are promising materials for nonvolatile memory applications. The device is built in the form of the metal–ferroelectric–insulator–semiconductor (MFIS) capacitance memory. The results demonstrated that LB films can provide devices with low-voltage operation. Thin Film Electronics successfully demonstrated roll-to-roll printed non-volatile memories based on ferroelectric polymers in 2009. The ferroelectric effect always relates the various force to electric properties, which can be applied in transducers. The flexibility and low cost of polymers facilitates the application of ferroelectric polymers in transducers. The device configuration is

title: Weather testing of polymers

text: Weather testing of polymers Weather testing of polymers is the controlled polymer degradation and polymer coating degradation under lab or natural conditions. Just like erosion of rocks, natural phenomena can cause degradation in polymer systems. The elements of most concern to polymers are ultraviolet radiation, moisture and humidity, high temperatures and temperature fluctuations. Polymers are used in everyday life, so it is important for scientists and polymer producers to understand durability and expected lifespan of polymer products. Paint, a common polymer coating, is used to change the colour, change the reflectance (gloss), as well as forming a protective coating. The

title: Heparin mimicking polymers

text: polymers. Events such as the 2008 heparin contamination event, and mad cow disease further enhance the new demand for more robust anticoagulants. Additionally prolonged use of heparin results in heparin induced thrombocytopenia. Three aspects of synthetic mimicking polymers are currently focused on: mimicking anionic sulfate domains of heparin, polymerization of sulfated saccharides and sulfation of natural occurring GAGs. Heparin mimicking polymers can be synthesized through a variety of mechanisms. To begin, monomers can be either be synthesized or purchased from avenues such as Sigma Aldrich. The monomers are the basic subunits of the polymer and can be designed to incorporate

title: Electroactive polymers

text: applied voltage and show low impedance. Ionic polymer-metal composites work through electrostatic attraction between the cationic counter ions and the cathode of the applied electric field, a schematic representation is shown in Figure 3. These types of polymers show the greatest promise for bio-mimetic uses as collagen fibers are essentially composed of natural charged ionic polymers. Nafion and Flemion are commonly used ionic polymer metal composites. Stimuli-responsive gels (hydrogels, when the swelling agent is an aqueous solution) are a special kind of swellable polymer networks with volume phase transition behaviour. These materials change reversibly their volume, optical, mechanical and other

title: Ferroelectric polymers

text: the entire body undergoes polarization, and the requirement of heat is not necessary. Although they differ from electrets, they are referred to as electrets often. Ferroelectric polymers fall into a category of ferroelectric materials known as a 'order-disorder' material. This material undergoes a change from randomly oriented dipoles which are paraelectric, to ordered dipoles which become ferroelectric. After the discovery of PVDF, many other polymers have been sought after that contain ferroelectric, piezoelectric, and pyroelectric properties. Initially different blends and copolymers of PVDF were discovered, such as a polyvinylidene fluoride with poly(methyl methacrylate). Other structures were discovered to possess ferroelectric

title: PH-sensitive polymers

text: given application. Confocal microscopy, scanning electron microscopy, Raman spectroscopy, and atomic force microscopy are all used to determine how the surface of a polymer changes in response to pH. pH sensitive polymers have been considered for use in membranes. A change in pH could change the ability of the polymer to let ions through, allowing it to act as a filter. pH sensitive polymers have been used to modify the surfaces of materials. For example, they can be used to change the wettability of a surface. Biomedical Use pH sensitive polymers have been used for drug delivery. For example, they

title: Crystallization of polymers

text: as polarized light microscopy and transmission electron microscopy. The methods used to determine the degree of crystallinity can be incorporated over time to measure the kinetics of crystallization. The most basic model for polymer crystallization kinetics comes from Hoffman nucleation theory. The crystallization process of polymers does not always obey simple chemical rate equations. Polymers can crystallize through a variety of different regimes and unlike simple molecules, the polymer crystal lamellae have two very different surfaces. The two most prominent theories in polymer crystallization kinetics are the Avrami equation and Lauritzen-Hoffman Growth Theory. Below their glass transition temperature, amorphous polymers

title: PH-sensitive polymers

text: the pH is less than the pKa of the polymer. Although many sources talk about synthetic pH sensitive polymers, natural polymers can also display pH-responsive behavior. Examples include chitosan, hyaluronic acid, and dextran. Chitosan, a frequently used example, is cationic. Since DNA is negatively charged, DNA could be attached to chitosan as a way to deliver genes to cells. Natural polymers have appeal because they display good biocompatibility, which makes them useful for biomedical applications. However, a disadvantage to natural polymers is that researchers can have more control over the structure of synthetic polymers and so can design those polymers

title: Ferroelectric polymers

text: to meet various requirements. A common approach for enhancing the dielectric constant is to disperse a high-dielectric-constant ceramic powder into the polymers. Popular ceramic powders are lead based complexes such as PbTiO and Pb(Zr,Ti)O. This can be disadvantageous because lead can be potentially harmful and at high particulate loading, the polymers lose their flexibility and a low quality composite is obtained. Current advances use a blending procedure to make composites that are based on the simple combination of PVDF and cheap metal powders. Specifically, Ni powders were used to make up the composites. The dielectric constants were enhanced from values

title: Ferroelectric polymers

text: polar conformation in PVDF (7.× 10 C-m per repeat). These polar conformations are the crucial factors that lead to the ferroelectric properties. Ferroelectric polymers and other materials have been incorporated into many applications, but there is still cutting edge research that is currently being done. For example, there is research being conducted on novel ferroelectric polymer composites with high dielectric constants. Ferroelectric polymers, such as polyvinylidene fluoride and poly[(vinylidenefluoride-co-trifluoroethylene] [P(VDF-TrFE)], are very attractive for many applications because they exhibit good piezoelectric and pyroelectric responses and low acoustic impedance, which matches water and human skin. More importantly, they can be tailored

title: Fire-safe polymers

text: naturally exhibit an intrinsic resistance to decomposition, while others are synthesized by incorporating fire-resistant additives and fillers. Current research in developing fire-safe polymers is focused on modifying various properties of the polymers such as ease of ignition, rate of heat release, and the evolution of smoke and toxic gases. Standard methods for testing polymer flammability vary among countries; in the United States common fire tests include the UL 94 small-flame test, the ASTM E 84 Steiner Tunnel, and the ASTM E 622 National Institute of Standards and Technology (NIST) smoke chamber. Research on developing fire-safe polymers with more desirable properties

title: Laser welding of polymers

text: wavelength, polymer absorptivity, polymer crystallinity, and additives (i.e. composite reinforcements, pigments, etc.). The absorption of the laser energy is what leads to heat generation in the welding of polymers. Heat is generated within the polymer when the photon energies of the laser beam cause the molecular bonds to vibrate. The heat distribution within a laser welded polymer is dictated by the Bouger-Lambert law of absorption. "I(z) = I(z=0) e" where I(z) is the laser intensity at a certain depth z, I(z=0) is the laser intensity at the surface, K is the absorption constant. Polymers often have secondary elements added to

title: Supramolecular polymers

text: held together in a proper proximity to afford long-lived charge separated states. Then a light-to-charge conversion system with faster photoinduced electron transfer and higher electron-transfer efficiency can be achieved in these artificial polymers. It is quite common that biomolecules, such as DNA, protein and the like, come into being through various noncovalent interactions in biological system. Likewise, supramolecular polymers assembles themself via a combination of noncovalent interactions. Such formation manner endows supramolecular polymers with features, being more sensitive to external stimuli and able to render reversibly dynamic changes in structures and functions. By modifying monomeric units of supramolecular polymers with

title: Knotted polymers

text: whilst maintaining neural cell viability above 80% four days post transfections. Knotted polymers Single Chain Cyclized/Knotted Polymers are a new class of polymer architecture with a general structure consisting of multiple intramolecular cyclization units within a single polymer chain. Such a structure was synthesized via the controlled polymerization of multivinyl monomers, which was first reported in Dr. Wenxin Wang’s research lab. These multiple intramolecular cyclized/knotted units mimic the characteristics of complex knots found in proteins and DNA which provide some elasticity to these structures. Of note, 85% of elasticity in natural rubber is due to knot-like structures within its molecular

title: Knotted polymers

text: another chain. Once the monomers are converted to short chains, the intermolecular combination increases and allows the formation of hyperbranched structures with a high density of branching and vinyl functional groups. Single chain cyclized polymers consist of multiple cyclized rings which afford them some unique properties, including high density, low intrinsic viscosity, low translational friction coefficients, high glass transition temperatures, and excellent elasticity of the formed network. In particular, an abundance of internal space makes the single chain cyclized polymers ideal candidates as efficient cargo-carriers. It is well established that the macromolecular structure of nonviral gene delivery vectors alters their

title: Knotted polymers

text: reacts with a vinyl functional group on its own chain, rather than with another growing chain in the reaction system. In this way the growing polymer chain covalently links to itself in a fashion similar to that of a knot in a piece of string. As such, single chain cyclized/knotted polymers consist of many of these links (intramolecularly cyclized), as opposed to other polymer architectures including branched and crosslinked polymers that are formed by two or more polymer chains in combination. A simple modification to atom transfer radical polymerization (ATRP) was introduced in 2007 to kinetically control the polymerization by

title: Knotted polymers

text: Knotted polymers Single Chain Cyclized/Knotted Polymers are a new class of polymer architecture with a general structure consisting of multiple intramolecular cyclization units within a single polymer chain. Such a structure was synthesized via the controlled polymerization of multivinyl monomers, which was first reported in Dr. Wenxin Wang’s research lab. These multiple intramolecular cyclized/knotted units mimic the characteristics of complex knots found in proteins and DNA which provide some elasticity to these structures. Of note, 85% of elasticity in natural rubber is due to knot-like structures within its molecular chain. An intramolecular cyclization reaction is where the growing polymer chain

title: Ferroelectric polymers

text: Clark and Lagerwall had done work on the fast electrooptic effect in a surface-stabilized ferroelectric liquid crystal (SSFLC) structure. This opened up promising possibility of technical applications of ferroelectric liquid crystals in high-information display devices. Through applied research, it was shown that SSFLC structure has faster switching times and bistability behavior in comparison with commonly used nematic liquid crystal displays. In the same time period, the first side-chain liquid crystalline polymers (SCLCP) were synthesized. These comb-like polymers has mesogenic side chains that are covalently bonded (via flexible spacer units) to the polymer backbone. The most important feature of the SCLCP's

title: Thermoresponsive polymers in chromatography

text: Thermoresponsive polymers in chromatography Thermoresponsive polymers can be used as stationary phase in liquid chromatography. Here, the polarity of the stationary phase can be varied by temperature changes, altering the power of separation without changing the column or solvent composition. Thermally related benefits of gas chromatography can now be applied to classes of compounds that are restricted to liquid chromatography due to their thermolability. In place of solvent gradient elution, thermoresponsive polymers allow the use of temperature gradients under purely aqueous isocratic conditions. The versatility of the system is controlled not only through changing temperature, but through the addition of

title: Mechanically gradient polymers

text: Mechanically gradient polymers Polymer gradient materials (PGM) are a class of polymers with gradually changing mechanical properties along a defined direction creating an anisotropic material. These materials can be defined based upon the direction and the steepness of the gradient used and can display gradient or graded transitions. A wide range of methods can be used to create these gradients including gradients in reinforcing fillers, cross-link density or porosity to name a few. 3D printing has been used to combine several of these methods in one manufacturing technique. These materials can be inspired by nature where mechanical gradients are used

title: Alamanda Polymers

text: Osborn, F. Greco J. Med. Chem. 2011, 54, 5255-5259. Alamanda Polymers Alamanda Polymers, Inc. is a life sciences company that was formed in 2007 that specializes in formation of polyamino acids to specific chain links for research purposes. Alamanda Polymers was formed in 2007 and produces specialized polyamino acids to specific chain links for research purposes. E. Tkachenko, M. Sabouri-Ghomi, O. Pertz, C. Kim, E. Gutierrez, M. Machacek, A. Groisman, G. Danuser, M. H. Ginsberg Nat. Cell Biol. 2011, 13, 660-667. A. Romoser, D. Ritter, R. Majitha, K. E. Meissner, M. McShane, C. M. Sayes PLoS One 2011, 6, e22079.

title: Ferroelectric polymers

text: the 1970s and 1980s, these polymers were applied to data storage and retrieval. Subsequently, there has been tremendous growth during the past decade in exploring the materials science, physics, and technology of poly(vinylidenefluoride) and other fluorinated polymers. Copolymer PVDF with trifluoroethylene and odd-numbered nylons were additional polymers that were discovered to be ferroelectric. This propelled a number of developing applications on piezoelectricity and pyroelectricity. The easiest way of synthesizing PVDF is the radical polymerization of vinylidene fluoride (VF), however, the polymerization is not completely regiospecific. The asymmetric structure of VF leads to the orientation isomers during the polymerization. The configuration

title: Supramolecular polymers

text: develop self-healing materials based on noncovalent bonds. Compared with self-healing materials based on covalent bonds, these supramolecular polymers-based self-healing materials can restore the initial structure and function of polymers before being exposed to damages, and can also undergo repeating damage-heal process. To achieve the light-to-charge conversion is the prerequisite step in artificial photosynthesis systems. By incorporating electron donors and electron acceptors into the supramolecular polymers, a number of artificial systems, including photosynthesis system, can be constructed. Owing to the existence of more than one interactions (π-π interaction, hydrogen bonding interaction and the like), electron donor and electron acceptor can be

title: Depolymerizable polymers

text: and explained in terms of the thermodynamics of a reversible propagation step by Dainton and Ivin. The first application of depolymerizable polymers is in transient electronics. Over the past several decades in the electronics industry, the research focus has been on durable and high-strength polymeric materials. Today, however, fast growing consumer electronic products and environmental concerns on electronic wastes, has increased the need for sustainable, recyclable materials. For example, a group of researchers employed light-sensitive poly(phthalaldehyde) as substrate materials for circuits. The destruction of the polymer substrate was triggered by UV irradiation (~379 nm). Depolymerizable polymers Depolymerizable polymers or Low-Ceiling

title: Alamanda Polymers

text: Alamanda Polymers Alamanda Polymers, Inc. is a life sciences company that was formed in 2007 that specializes in formation of polyamino acids to specific chain links for research purposes. Alamanda Polymers was formed in 2007 and produces specialized polyamino acids to specific chain links for research purposes. E. Tkachenko, M. Sabouri-Ghomi, O. Pertz, C. Kim, E. Gutierrez, M. Machacek, A. Groisman, G. Danuser, M. H. Ginsberg Nat. Cell Biol. 2011, 13, 660-667. A. Romoser, D. Ritter, R. Majitha, K. E. Meissner, M. McShane, C. M. Sayes PLoS One 2011, 6, e22079. C. Fante, A. Eldar-Boock, R. Satchi-Fainaro, H. M. I.

title: PH-sensitive polymers

text: polymers because molecular weight distribution of the final polymers can be controlled. Examples include group transfer polymerization (GTP), atom transfer radical polymerization (ATRP), and reversible addition-fragmentation chain transfer (RAFT). Graft copolymers are a popular type to synthesize because their structure is a backbone with branches. The composition of the branches can be changed to achieve different properties. Hydrogels can be produced using emulsion polymerization. Several methods can be used to measure the contact angle of a water drop on the surface of a polymer. The contact angle value is used to quantify wettability or hydrophobicity of the polymer. Equal to

title: Heparin mimicking polymers

text: °C), it transitions to its rubbery state, allowing the nitinol to resume its corkscrew shape. Retrieval of the blood clot occurs through a pull back motion. The nitinol is engulfed in a tight space even though it is expanding and as a result retreats thus extracting the tissue. Heparin mimicking polymers Heparin Mimicking Polymers are synthetic compounds that possess similar characteristics to heparin, that is it can be used clinically as an anticoagulant. These compounds like heparin possess a negative charge density that allows it to interact and inhibit the coagulation process. Glucose or mannose-contain n-alkyl urea peptoid oligomer, glucose

title: Fracture in polymers

text: to conditions of tensile fatigue, failure occurs when a minimum strain is reached. this means that the lifetime of nylon material is dictated by the time under load and not on the number of cycles Fatigue failure in these reinforced polymers is due to the formation of micro cracks that are easily initiated, and which coalesce into one crack, causing the final failure A good polymer is generally defined as one capable of absorbing a large amount of energy before failure. Polycarbonates have one of the highest impact resistance values. However, amorphous polymers exhibit brittle behaviour under impact, especially if

title: Fracture in polymers

text: number cause a fracture tip initialization to occur followed by its growth. Polymers are viscoelastic by nature, and exhibit mechanical hysteresis even at moderate strains due to continuous elongation and contraction. Some of this inelastic deformation energy is dissipated as heat within the polymer, and consequently the materials temperature will rise as a function of frequency, testing temperature, the stress cycle and the type of polymer. As the temperature within the polymer rises, the stiffness and yield strength will fall, and thermal failure becomes a possibility as deformation levels become excessive. Fracture mechanics in polymers has become an increasingly concerning

title: Crystallization of polymers

text: are usually hard and brittle because of the low mobility of their molecules. Increasing the temperature induces molecular motion resulting in the typical rubber-elastic properties. A constant force applied to a polymer at temperatures above T results in a viscoelastic deformation, i.e., the polymer begins to creep. Heat resistance is thus given for amorphous polymers just below the glass transition temperature. Relatively strong intermolecular forces in semicrystalline polymers prevent softening even above the glass transition temperature. Their elastic modulus changes significantly only at high (melting) temperature. It also depends on the degree of crystallinity: higher crystallinity results in a harder

title: Structurally nanoengineered antimicrobial polypeptide polymers

text: or S32 (32 arm SNAPP). The polymerized peptide chains result in several positively charged primary ammonium cations, which help adhere the negatively charged end of the phospholipid bi-layer. Structurally nanoengineered antimicrobial polypeptide polymers Structurally nanoengineered antimicrobial polypeptide polymers (SNAPPs) are a type of artificially designed synthetic antimicrobial peptide. The development of the polymers is potentially a treatment for bacterial diseases. The research takes a novel approach to combating bacteria; rather than poisoning them as antibiotics do, SNAPPs and other antimicrobial peptides tear the bacteria apart. The molecule destabilizes the structure of the outer membrane and cytoplasmic membrane in multi-drug resistant

text: Structurally nanoengineered antimicrobial polypeptide polymers Structurally nanoengineered antimicrobial polypeptide polymers (SNAPPs) are a type of artificially designed synthetic antimicrobial peptide. The development of the polymers is potentially a treatment for bacterial diseases. The research takes a novel approach to combating bacteria; rather than poisoning them as antibiotics do, SNAPPs and other antimicrobial peptides tear the bacteria apart. The molecule destabilizes the structure of the outer membrane and cytoplasmic membrane in multi-drug resistant gram-negative bacteria with no resistance observed by the researchers through multiple bacterial generations. While no human trials have been approved yet, the molecule has been tested "in vivo"

title: Laser welding of polymers

text: used to create butt joints and lap joints with complete penetration. Laser wavelengths between 2 and 10.6μm are used for this process due to their high absorptivity in polymers. Similar to other noncontact methods, such as noncontact hot plate welding, the laser irradiates the contact surfaces of a joint. Once the surface layer of the material melts, the two parts are brought together, with pressure, and the joint is made. Through transmission laser welding of polymers relies on a joint in which the two components possess different optical properties. One of the materials must be transparent to the laser wavelength

title: Laser welding of polymers

text: material through the use of additives or dyes can influence the laser interaction as well. Reflection of incident laser radiation is typically on the order of 5 to 10% in most polymers. The presence of spherulites in semi-crystalline polymers along with any reinforcements may lead to further reflection. Transmission of laser energy through certain polymers allows for processes such as through transmission welding. Certain polymers will exhibit transparency to set wavelengths of energy, this property is typically influenced by the additives present within the polymer. The amount of laser energy absorbed by a polymer is a function of the laser

title: Fracture in polymers

text: Fracture in polymers Polymer fracture is the study of the fracture surface of an already failed material to determine the method of crack formation and extension in polymers both fiber reinforced and otherwise. Failure in polymer components can occur at relatively low stress levels, far below the tensile strength because of four major reasons: long term stress or creep rupture, cyclic stresses or fatigue, the presence of structural flaws and stress-cracking agents. Formations of submicroscopic cracks in polymers under load have been studied by x ray scattering techniques and the main regularities of crack formation under different loading conditions have

title: What Are Records?

text: What Are Records? What Are Records? (or W.A.R.?) is an independent record label located in Boulder, Colorado. Founded in New York City in 1991 by owner Rob Gordon, former director of A&R at EMI, the company moved to Boulder in 1994. W.A.R.? has released over 100 records by Frank Black (of the Pixies), Bill Burr, Stephen Lynch, The Samples, Maceo Parker, Melissa Ferrick, and Whitest Kids U' Know. What Are Records? was founded in Gordon’s New York City loft in 1991. From the beginning, it fostered a direct-to-stores and direct-to-consumers distribution strategy Friend of Gordon and The Samples then-manager, Ted

title: Laser welding of polymers

text: the quality of the weld. Colorants (pigments) are added to polymers for various reasons including aesthetics and functional requirements (such as optics). Certain color additives, such as titanium dioxide, can have a negative impact on the laser weldability of a polymer. The titanium dioxide provides a white coloring to polymers but also scatters laser energy making it difficult to weld. Another color additive, carbon black, is a very effective energy absorber and is often added to create welds. By controlling the concentration of carbon black with the absorbing polymer it is possible to control the effective area of the laser

title: Laser welding of polymers

text: when compared to the other beam sources, however they are adequate for performing polymer welds. Diode lasers can be either fiber delivered or local to the weld location. The relatively small size makes assembling arrays for larger foot prints possible. They typically operate in the 780 - 980nm wavelength range. Carbon dioxide lasers typically have a wavelength of 10.6μm which is readily absorbed by most polymers. This type of laser can be used in direct welding of polymers or cutting. The beam is commonly delivered by mirrors. typically have a wavelength in the range of 0.8 - 1.1μm, with 1064nm

title: Grupa Azoty ATT Polymers GmbH

text: Kell and Jacek Dychtoń, whereas the members of the Supervisory Board are Andrzej Skolmowski, Małgorzata Malec and Witold Szczypiński. Grupa Azoty ATT Polymers GmbH mainly specialises in polyamide 6 production. Its high viscosity allows for its application in, e.g. production of bi-oriented foil, which is used in work with foods. A product named Alphalon™ was distinguished at fairs PLASTPOL 2011 in Kielce. The production abilities in Grupa Azoty ATT POLYMERS are estimated as 45 thousand tons per year. In 2014, Grupa Azoty gained the possibility to open the next factory of polyamide 6 in Tarnów as a part of Special

title: Photo-oxidation of polymers

text: Photo-oxidation of polymers Photo-oxidation is the degradation of a polymer surface in the presence of oxygen or ozone. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers. Photo-oxidation is a chemical change that reduces the polymer's molecular weight. As a consequence of this change the material becomes more brittle, with a reduction in its tensile, impact and elongation strength. Discoloration and loss of surface smoothness accompany photo-oxidation. High temperature and localized stress concentrations are factors that significantly increase the effect of photo-oxidation. Aldehydes, ketones and

title: Electroactive polymers

text: used in acoustic transducers and electromechanical actuators because of their inherent piezoelectric response, and as heat sensors because of their inherent pyroelectric response. Electrostrictive graft polymers consist of flexible backbone chains with branching side chains. The side chains on neighboring backbone polymers cross link and form crystal units. The backbone and side chain crystal units can then form polarized monomers, which contain atoms with partial charges and generate dipole moments, shown in Figure 2. When an electrical field is applied, a force is applied to each partial charge and causes rotation of the whole polymer unit. This rotation causes electrostrictive

title: Electroactive polymers

text: similar effect. In 1977 the first electrically conducting polymers were discovered by Hideki Shirakawa "et al." Shirakawa along with Alan MacDiarmid and Alan Heeger demonstrated that polyacetylene was electrically conductive, and that by doping it with iodine vapor, they could enhance its conductivity by 8 orders of magnitude. Thus the conductance was close to that of a metal. By the late 1980s a number of other polymers had been shown to exhibit a piezoelectric effect or were demonstrated to be conductive. In the early 1990s, ionic polymer-metal composites (IPMCs) were developed and shown to exhibit electroactive properties far superior to

title: Electroactive polymers

text: or alkali solutions, they would respond with a change in volume. The collagen filaments were found to expand in an acidic solution and contract in an alkali solution. Although other stimuli (such as pH) have been investigated, due to its ease and practicality most research has been devoted to developing polymers that respond to electrical stimuli in order to mimic biological systems. The next major breakthrough in EAPs took place in the late 1960s. In 1969 Kawai demonstrated that polyvinylidene fluoride (PVDF) exhibits a large piezoelectric effect. This sparked research interest in developing other polymers systems that would show a

title: MBA Polymers

text: in their new products. Having opened its first recycling facility in 1994, MBA Polymers also has recycling plants in the UK and in China, and has recently announced plans to relocate its research and development facilities from the United States to the United Kingdom. In 2004 MBA Polymers created a joint venture with Guangzhou Iron and Steel Enterprises Holdings Ltd to establish its sustainable recycling operations in China. MBA Polyers' operations in China now employ over 160 people. The company has invested USD$15million in the recycling plant. The company expanded its operations to Austria in 2006. MBA has more than

title: We Are What We Are (2010 film)

text: We Are What We Are (2010 film) We Are What We Are () is a 2010 Mexican horror film directed by Jorge Michel Grau. The movie is about a family who, after the death of the father, try to continue on with a disturbing, ritualistic tradition. The film stars Paulina Gaitán and Daniel Giménez Cacho. In the opening scene, Dad dies on the sidewalk at a local shopping mall. At home, his family is wondering what has become of him. Dad is a watchmaker who repairs watches at the local street market, and the family's sole means of support. As

title: What Are Words (album)

text: What Are Words (album) What Are Words is the debut album of the American singer Chris Medina. The album was released by Sony Music contains 11 pop-rock songs, some of them sensitive ballads, others more energetic and rocking. Album included the title track "What Are Words", a touching track inspired by Chris Medina's fiancé who had a serious brain injury after a car accident in 2009. Although "What Are Words" was only a minor hit in the United States, it was a big hit in Scandinavian countries topping both Norwegian "VG-lista" Singles Chart and the Swedish "Sverigetopplistan" Singles Chart. It

title: Electroactive polymers

text: by Ron Pelrine developed an electroactive polymer using silicone and acrylic polymers; the technology was spun off into the company Artificial Muscle in 2003, with industrial production beginning in 2008. In 2010, Artificial Muscle became a subsidiary of Bayer MaterialScience. EAP can have several configurations, but are generally divided in two principal classes: Dielectric and Ionic. Dielectric EAPs are materials in which actuation is caused by electrostatic forces between two electrodes which squeeze the polymer. Dielectric elastomers are capable of very high strains and are fundamentally a capacitor that changes its capacitance when a voltage is applied by allowing the

title: Grupa Azoty ATT Polymers GmbH

text: Grupa Azoty ATT Polymers GmbH Grupa Azoty ATT Polymers GmbH ("abridged name: Grupa Azoty ATT POLYMERS") – one of the leading enterprises producing polyamide 6 (PA6) in Western Europe. Acquired by Zakłady Azotowe w Tarnowie-Mościcach in 2009, currently a member of Grupa Azoty, leader in production of fertilizers, construction materials and caprolactam. Grupa Azoty ATT POLYMERS is seated in Guben, (Germany). The company has its own laboratory and cooperates with a modern laboratory of the Grupa Azoty located in Tarnów. Its activity is focused on both development of existing products as well as on research on new products. In 1958,

title: Knotted polymers

text: transfection efficacy and cytotoxicity. The cyclized structure has been proven to reduce cytotoxicity and increase circulation time for drug and gene delivery applications. The unique structure of cyclizing chains provides the single chain cyclized polymers a different method of interaction between the polymer and plasmid DNA, and results in a general trend of higher transfection capabilities than branched polymers. Moreover, due to the nature of the single chain structure, this cyclized polymer can “untie” to a linear chain under reducing conditions. Transfection profiles on astrocytes comparing 25 kDa-PEI, SuperFect® and Lipofectamine®2000 and cyclized polymer showed greater efficiency and cell viability

title: Electroactive polymers

text: use as graphic displays for visually impaired such displays are interesting as free programmable keys of touchpads and consoles. EAP materials have huge potential for microfluidics e.g. as drug delivery systems, microfluidic devices and lab-on-a-chip. A first microfluidic platform technology reported in literature is based on stimuli-responsive gels. To avoid the electrolysis of water hydrogel-based microfluidic devices are mainly based on temperature-responsive polymers with lower critical solution temperature (LCST) characteristics, which are controlled by an electrothermic interface. Two types of micropumps are known, a diffusion micropump and a displacement micropump. Microvalves based on stimuli-responsive hydrogels show some advantageous properties such

title: Spinning (polymers)

text: air and drawn, and then submerged into a liquid bath. This method is used in Lyocell spinning of dissolved cellulose. A solution consisting of a fiber-forming material and a solvent is extruded through a spinneret. A stream of hot air impinges on the jets of solution emerging from the spinneret, the solvent evaporates, and solid filaments are left behind. Melt spinning is used for polymers that can be melted. The polymer solidifies by cooling after being extruded from the spinneret. Nylon, olefin, polyester, saran, and sulfar are produced via this process. Pellets or granules of the solid polymer are fed

title: Spinneret (polymers)

text: electrospinning and electrospraying applications. They are sometimes called "coaxial needles," or "coaxial emitters." Spinnerets are usually made of metals with melting points too low to withstand the heating processes employed in industrial metallurgy, and thus are generally not used in constructing metals. Spinneret (polymers) A spinneret is a device used to extrude a polymer solution or polymer melt to form fibers. Streams of viscous polymer exit via the spinneret into air or liquid leading to a phase inversion which allows the polymer to solidify. The individual polymer chains tend to align in the fiber because of viscous flow. This airstream

title: Become What You Are

text: "My Sister," and "Spin the Bottle", stating that "her talents are strong enough to carry the album over the weak spots." The album was ranked No. 9 in "NME"s Albums of the Year list for 1993. Credits are adapted from the album's liner notes. Album Singles Become What You Are Become What You Are is the debut studio album by the American alternative rock band the Juliana Hatfield Three, released on August 3, 1993, by Mammoth Records. The album includes the hit singles "My Sister" and "Spin the Bottle". The singer and guitarist, Juliana Hatfield, recorded "Become What You Are"

title: What Are Records?

text: Wilcox Everything Fancey Felicia Michaels Figurine Frank Black Glenn Tilbrook Hazard House of Large Sizes The Innocence Mission Jeep Joseph Brenna Le Concorde Lir Lloyd Cole Luce Maceo Parker Melissa Ferrick Munly The Ocean Blue The Poppy Family Primitive Radio Gods The Radiators Sally Taylor The Samples Sean Kelly Stuart Matthewman Sungha Jung The Swayback 24-7 Spyz Tim Finn Tony Furtado Ugly Americans What Are Records? What Are Records? (or W.A.R.?) is an independent record label located in Boulder, Colorado. Founded in New York City in 1991 by owner Rob Gordon, former director of A&R at EMI, the company moved

title: What Are Words

text: went number one in Sweden on July 1, 2011 and remained for 8 straight weeks. It was awarded a 2X platinum certification in Sweden on September 20, 2011. What Are Words "What Are Words" is a hit song written by Rodney Jerkins, Andre Lindal and Lauren Christy, and performed by American singer Chris Medina. It was released on February 25, 2011, the day after his surprising elimination on the reality TV show American Idol. The song is a tribute to his fiancée who suffered a brain injury as the result of a car wreck and is about promises, commitment and

title: What Are Words

text: What Are Words "What Are Words" is a hit song written by Rodney Jerkins, Andre Lindal and Lauren Christy, and performed by American singer Chris Medina. It was released on February 25, 2011, the day after his surprising elimination on the reality TV show American Idol. The song is a tribute to his fiancée who suffered a brain injury as the result of a car wreck and is about promises, commitment and keeping your word. The music video was shot at Atlantis studios in Hollywood and was released days after the single. The video depicts Medina in the actual recording

title: Chemically assisted degradation of polymers

text: the protective materials, the polymer and surrounding environment. Chemically assisted degradation of polymers Chemically assisted degradation of polymers is a type of polymer degradation that involves a change of the polymer properties due to a chemical reaction with the polymer’s surroundings. There are many different types of possible chemical reactions causing degradation however most of these reactions result in the breaking of double bonds within the polymer structure. One common example of chemically assisted degradation is the degradation of rubber by ozone particles. Ozone is a naturally occurring atmospheric molecule that is produced by electric discharge or through a reaction

text: Chemically assisted degradation of polymers Chemically assisted degradation of polymers is a type of polymer degradation that involves a change of the polymer properties due to a chemical reaction with the polymer’s surroundings. There are many different types of possible chemical reactions causing degradation however most of these reactions result in the breaking of double bonds within the polymer structure. One common example of chemically assisted degradation is the degradation of rubber by ozone particles. Ozone is a naturally occurring atmospheric molecule that is produced by electric discharge or through a reaction of Oxygen with solar radiation. Ozone is also

title: Knotted polymers

text: The resulting chain growth rate is slowed down to allow sufficient control over the reaction thus greatly increasing the percentage of multi-vinyl monomers in the reaction system (even up to 100 percent (homopolymerization)). Typically, single chain cyclized/knotted polymers are synthesized by deactivation enhanced ATRP of multivinyl monomers via kinetically controlled strategy. There are several main reactions during this polymerization process: initiation, activation, deactivation, chain propagation, intramolecular cyclization and intermolecular crosslinking. The polymerization process is explained in Figure 2. In a similar way to normal ATRP, the polymerization is started by initiation to produce a free radical, followed by chain propagation

title: We Are What We Are (2010 film)

text: Film4 FrightFest 2010. IFC Film will release the film in the United States as Video-on-demand. Artificial Eye released "We Are What We Are" in the UK on 12 November 2010. The score was composed by Odd Crew. Deborah Young of "Reuters" said, that "We Are What We Are" "is perhaps too dark and relentlessly humorless to find wide international audiences." Young stated that "another limiting factor is the difficulty of identifying with any of the characters, who are played expressively but still remain abstract and alien, distant from the viewer." Review aggregator Rotten Tomatoes gives the film a score of

title: Become What You Are

text: Become What You Are Become What You Are is the debut studio album by the American alternative rock band the Juliana Hatfield Three, released on August 3, 1993, by Mammoth Records. The album includes the hit singles "My Sister" and "Spin the Bottle". The singer and guitarist, Juliana Hatfield, recorded "Become What You Are" with drummer Todd Philips, formerly of Moving Targets and Bullet LaVolta, and bassist Dean Fisher, who she met during high school in Duxbury, Massachusetts. Unlike her previous album "Hey Babe", which deals with personal topics, Hatfield decided to write songs about other things and make them