bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Processing on the Structure and Properties of Crosslinked Closed Cell Polyethylene Foams
Authors: Rodríguez-Pérez M.A. , Almanza O. , Ruiz-Herrero J.L. , de Saja J.A.
Published: September 2018

This paper analyses the relationships between production, structure and properties of a collection of crosslinked closed cell polyethylene foams. Foams with similar densities produced from a similar base polymer and manufactured using three different technologies (high pressure nitrogen solution process, compression moulding and semicontinuous processing) have been characterised. On the one hand, several foam characteristics such as density, cell diameter, cell wall thickness, cell shape, fraction of mass in the edges, gel content, crystallinity and melting temperature have been measured and related to the way in which the foams were produced. On the other hand, three important physical properties such as thermal conductivity, Young's modulus and thermal expansion have been measured analysing the experimental results in terms of the previously cited foam characteristics. The results have shown that the production route used to manufacture the foam strongly influences the foam structure and as a consequence the main physical properties.
Graphitic Foam with High Strength and High Thermal Conductivity Doped by Tungsten
Authors: Wang Yong , Cao Lingling , Gao Jin , Wang Yimin
Published: September 2018

A graphitic foam with high strength and high thermal conductivity was prepared through the incorporation of tungsten particle into mesophase pitch precursor. Results show that tungsten acts as catalysts to accelerate the graphitization of carbon, promote more perfect and larger crystallites and enhance the conductive and mechanical properties. Test results reveal that tungsten doped graphitic foam (TDGF) has excellent compressive strength and high thermal conductivity, with highest values reaching 29.6 MPa and 117.8 Wm−1 K−1 for a tungsten concentration of 12 wt% in the precursor materials. More compact struts and cell walls stacked by more uniform pores were observed by scanning electron microscope in graphitic foam. Correlation between the content of dopant and the properties and microstructure of TDGF was discussed.
Tensile Modulus Prediction of Structural Foams using Density Profiles
Authors: Barzegari Mohamad Reza , Rodrigue Denis
Published: September 2018

In this study, the tensile moduli of LDPE structural foams are related to their density profiles measured by X-ray densitometry. A review of the most important mechanical models for cellular materials are presented and adapted to include the complete density profile. Using experimental data, predicted values with this new approach are much closer (4% deviation) when compared with other models for the range of parameters studied.
Effect of As-Mold Rapid Cooling on Shrinkage and Morphology of Core Region of Injection Molded Parts Using Microcellular Foaming Process
Authors: Zafar Rizwan , Kim Hak Bin , Jeon Byung Joo , Cha Sung Woon
Published: September 2018

Shrinkage is a common problem in injection molded parts which considerably affects the dimensional accuracy of the product. In this paper normal cooling (NC) and as-mold rapid cooling (RC) of core region of injection molded samples have been used to study the% shrinkage of Acetal copolymer with increased weight reduction using Microcellular Foaming Process (MCPs). The results show that shrinkage reduction is not only associated with weight reduction (WR) but also directly related with the decrease in crystalline phase and as-mold RC rate.14% decrease in linear shrinkage by NC with 5.5% loss in crystallinity and 24% decrease in linear shrinkage with 9% loss in crystallinity with RC were observed at 10% weight reduction at same mold temperature. Furthermore, RC of core region resulted into decreased cells size and increased cells density. The study can be useful to control the dimensional tolerances and morphology of the injection molded parts by RC of still molten core region.
Prediction of the Effective Thermal Conductivity of Graphitic Foam Using a Fractal Model
Authors: Xu Zhi , Wang Yong , Wang Yimin
Published: September 2018

Graphitic foams prepared by thermal treating of mesophase pitch under certain temperature and pressure have good thermal conduction after being graphitized. Fractal theory has been applied to study the heat transfer phenomena in porous media and was used here to calculate the thermal conductivity of the graphitic foams. A thermal conductivity model of graphitic foam is proposed by deducing the area fractal dimension of graphitic foam and by using thermal resistance method. The effective thermal conductivity of graphitic foam is computed. The predicted value by fractal model is well consistent with that of the actually observed for graphitic foam.
Microcellular Polycarbonate with Improved Notched Impact Strength Produced by Injection Moulding with Physical Blowing Agent
Authors: Bledzki A.K. , Rohleder M. , Kirschling H. , Chate A.
Published: September 2018

Polycarbonate has the reputation of having a tough breaking behaviour, but it is often unknown that this applies only to special conditions. The impact strength of polycarbonate depends on the temperature, the thickness (with a tough brittle transition at thickness increases), contribution of notch tip radius, impact speed, physical blowing agent, molecular weight of the polymer and the processing parameters. Research results indicated that microcellular foams produced by injection moulding with physical blowing agent (MuCell™ Technology by Trexel) shows significant higher notched impact strength than compact polycarbonate, if the compact material is brittle under the same test parameters. However, if the compact polycarbonate breaks toughly, the notched impact strength of the foamed material is always lower. Therefore, it is highly important to pay attention to the test parameters and conditions when comparing the toughness of the foamed with the compact material. The toughness of microcellular foams shows similar properties to PC/ABS and PC/PP blend systems, which provides the possibility to combine the higher impact strength with the advantages of microcellular foaming like weight reduction, lower shrinkage, shorter cycle times, lower clamp forces and reduced melt viscosity.

In order to use technologies and conditions which are applied in the polymer industry, all materials were produced by an injection moulding process. Special processing technologies like gas counter pressure and precision mould opening were used in order to reach microcellular foam structures with cell diameters around 10 μm. These technologies yield exactly adjustable foam morphologies. Special morphologies are required to improve the notched impact strength of the foamed material. Two different equivalent models were extracted from the analyses, which indicate significant higher notched impact strength than the compact material under the same test conditions. The knowledge of the ideal foam morphologies enables the industry to produce foamed materials with improved mechanical properties.
Mechanical Behaviour at Low Strains of LDPE Foams with Cell Sizes in the Microcellular Range: Advantages of Using These Materials in Structural Elements
Authors: Rodriguez-Perez M.A. , Lobos J. , Perez-Muñoz C.A. , de Saja J.A. , Gonzalez L. , del Carpio B.M.A.
Published: September 2018

This paper presents the production method and the compressive mechanical response at low strains for a collection of polyethylene foams with high densities and cell sizes in the microcellular range. The materials were produced using an improved compression moulding technique that allows and independent control of density and cell size.

The materials had a relative density between 0.27 and 0.92, an homogeneous and multi-structured cellular structure with dense skin and foamed core and cell sizes in the range 30 to 100 microns. The Young's modulus decreased with density. For relative densities higher than 0.7, the reduced Young's modulus of the foams was higher than that of the solid. In addition, it has been proved that variations in the cell size at constant density did not influence the Young's modulus. The advantages of using these materials for the production of plastic pipes have been analysed. In comparison with a solid pipe a reduction of the weight of foamed pipes loaded in compression of up to 40% can be reached.
The binary gas sorption in the bituminous coal of the Huaibei Coalfield in China
Authors: Zhang Lei , Ye Zhiwei , Li Mingxue , Zhang Cun , Bai Qingsheng , Wang Chen
Published: September 2018

Knowledge of the gas sorption characteristics of a coal not only helps to explain the mechanism of enhanced coalbed methane recovery but also provides an important basis for simultaneous coal and gas extraction. In consequence, the pure and binary gas excess sorption capacity of methane, carbon dioxide, and nitrogen of bituminous coal samples derived from the Xutuan Coal Mine in Huaibei coalfield, in Anhui Province in China, was measured using the volumetric method. The fitting analysis of the pure gas Langmuir adsorption model was carried out. The binary gas excess sorption measurement showed that the final sorption capacity of bituminous samples was the same no matter what the gas adsorption order of competitive adsorption and displacement adsorption. Hence, coal gas adsorption is physical adsorption, i.e. the different adsorption and desorption process of gas molecules does not affect the final adsorption amount of coal to each component of gas. Using the fitting parameters obtained by the Langmuir equation, the extended Langmuir equation was used to predict the adsorption capacity for each component of the binary gas. The comparison between predicted adsorption capacity and measured adsorption capacity showed that the extended Langmuir equation can better describe the trend of the adsorption isotherm curves of a binary gas under different pressures. The separation coefficient and displacement coefficient were defined from Langmuir adsorption theory. The separation coefficient involves the proportion of each component in the free phase and the proportion of each component in the adsorption phase. The displacement coefficient involves the displacement ability of gas molecules at adsorption sites by free gas molecules.
A new era for stroke therapy: Integrating neurovascular protection with optimal reperfusion
Authors: Shi Ligen , Rocha Marcelo , Leak Rehana K , Zhao Jingyan , Bhatia Tarun N , Mu Hongfeng , Wei Zhishuo , Yu Fang , Weiner Susan L , Ma Feifei , Jovin Tudor G , Chen Jun
Published: September 2018

Recent advances in stroke reperfusion therapies have led to remarkable improvement in clinical outcomes, but many patients remain severely disabled, due in part to the lack of effective neuroprotective strategies. In this review, we show that 95% of published preclinical studies on “neuroprotectants” (1990–2018) reported positive outcomes in animal models of ischemic stroke, while none translated to successful Phase III trials. There are many complex reasons for this failure in translational research, including that the majority of clinical trials did not test early delivery of neuroprotectants in combination with successful reperfusion. In contrast to the clinical trials, >80% of recent preclinical studies examined the neuroprotectant in animal models of transient ischemia with complete reperfusion. Furthermore, only a small fraction of preclinical studies included long-term functional assessments, aged animals of both genders, and models with stroke comorbidities. Recent clinical trials demonstrate that 70%–80% of patients treated with endovascular thrombectomy achieve successful reperfusion. These successes revive the opportunity to retest previously failed approaches, including cocktail drugs that target multiple injury phases and different cell types. It is our hope that neurovascular protectants can be retested in future stroke research studies with specific criteria outlined in this review to increase translational successes.
Setting a Bad Example: Peer, Parental, and Celebrity Norms Predict Celebrity Bashing
Authors: Ouvrein Gaëlle , Pabian Sara , Machimbarrena Juan Manuel , Erreygers Sara , De Backer Charlotte J. S. , Vandebosch Heidi
Published: September 2018

The present study investigated the effect of descriptive and injunctive norms of peers, parents, and favorite celebrities on adolescents’ negative online behavior toward celebrities. The sample consisted of 1,255 adolescents ([Formula: see text] = 14.17, SD = 0.47). Adolescents indicated what their peers, parents, and favorite celebrities think of celebrity bashing (injunctive norms) and whether they engage in it (descriptive norms). The adolescents also indicated how often they had participated in negative online behavior toward celebrities and peers. The results revealed that compared with injunctive norms, descriptive norms are better predictors of adolescents’ negative online behavior toward celebrities. Focusing on the different role models, the impact of peers was the strongest for both mild and severe forms of celebrity aggression. Moreover, the results showed that adolescents who engage in negative online behavior directed at celebrities are likely to do the same regarding peers.
Time for a Marketing Curriculum Overhaul: Developing a Digital-First Approach
Authors: Rohm Andrew J. , Stefl Matthew , Saint Clair Julian
Published: September 2018

Academic programs and educators face numerous challenges related to teaching digital marketing. Today, the world of marketing is digital and marketing programs have struggled to maintain pace with the changes influencing marketing practice. The authors describe the M-School program at Loyola Marymount University, a program developed to address this challenge by placing digital marketing at the center of the curriculum. Through experiential learning and project-based learning, M-School courses expose students to real-life challenges involving ways in which companies and organizations generate consumer awareness, demand, and value given the significant digital shifts taking place in technology and consumer behavior. The authors highlight the creation of a digital-first curriculum that is aligned with industry practice and helps students develop the skills needed to become future proof and real-world ready. Quantitative and qualitative assessment over a three-year period points to the success of the M-School program in preparing students for careers in marketing. Lessons for the development of marketing curricula include the role of new course development, the need to integrate digital within existing courses, the role of a project-based learning approach with measurable outcomes, and the potential for designing transdisciplinary courses to foster students’ creative, critical thinking, communication, and collaborative skills.
Silicone Masterbatch Additives for Improved Plastics Processing
Authors: John V.B. , Rubroeder H.
Published: September 2018

For many years, conventional silicone oils have been used as internal and external lubricants for the processing of plastics. Although these products have produced the desired results in a variety of polymer types and applications, certain problems with handling have prevented their widespread use. To overcome these problems, Dow Corning recently introduced the MB 50 series of silicon masterbatches onto the European market. These are pellets with a 50% content of migration-stable, high-molecular silicon in different plastics such as PP, PE, HIPS, POM, ABS, PA 6 etc.
Nanocomposites - a New Class of Materials
Authors: Beyer G.
Published: September 2018

Nanocomposites are a new class of materials in the plastics industry. Their extraordinary new or improved material properties are the result of the extremely fine distribution of modified layered silicates. This article describes the different production methods and the possible structures of nanocomposites, followed by a summary of the most important properties of nanocomposites demonstrating the possible applications.
Topas® COC - the new product line by Ticona. 2. Applications
Authors: Mackasi L.
Published: September 2018

In the first part of this report we dealt with te production of the new cycloolefin copolymers, their physical and chemical properties and their processing by extrusion and injection moulding (refs. 1 – 6). In the present article we shall discuss the conditions for applications in the drug industry, medical and laboratory equipment, and optical and electrical applications, with some practical examples of these.
Investigation of the Degradation of Toxic Curing Accelerators and Antioxidants in Native Soil Flora
Authors: Büttner R. , Rakus S. , Taeger E.
Published: September 2018

It is known from investigations performed in landfill sites used for rubber waste that vulcanisation accelerations and anti-ageing agents are eluted by rain water and soil humidity. These rubber chemicals and partially formed degradation products [1,2] can reach and pollute the groundwater or may be mineralised beforehand by hydrolysis and biological degradation processes.
Matting of Silicone Sealants
Authors: Meyer J. , Scholz M.
Published: September 2018

At present, the options for the matting of silicone sealants, which may be required for technical or fashionable reasons, are very unsatisfactory and associated with detrimental impacts on the rheological and/or technical properties of the sealants.

This paper describes the use of a new type of matting agent for silicone sealants. In addition to the matting effects, it discusses the impacts on the rheological, mechanical and optical properties of matted silicone sealants of this type. Additional information is provided in the form of photographs and measurements of the surface roughness of matted sealants.
Composites Made from Thermoplastic Polymers with Carbon Nanotubes
Authors: Pötsche Ing. Petra , Leibniz A. Janke , Bhattacharyya A.A. , Goering H.
Published: September 2018

Carbon nanotubes are novel nanoscaled additives with excellent electrical and mechanical properties that make them suitable for endowing polymeric materials with conductivity and for mechanical reinforcement even in very low amounts. This paper describes possibilities for their incorporation in polymers by means of melt processing.
Silicone Rubbers in Medical Applications – Friction Reduction with LSR Top Coat
Authors: Ledig B.
Published: September 2018

Silicone rubbers (also known as polydimethyl siloxanes) which are used in medical and pharmaceutical applications have to fulfil a multitude of requirements. They must be biocompatible, i.e. comply with USP Class VI and ISO 10993 standards, and they need to be chemically resistant to a variety of cleaning fluids (CIP fluids) and resistant to various sterilisation techniques. The Silopren 4020-4080 series of liquid silicones (LSR) from Momentive Performance Materials fulfils these requirements. They are prepared in a special filling process and delivered in batches with an EP 1.3.2 certificate.

For some applications it is advantageous to reduce the coefficient of friction. This can be achieved with LSR Top Coat TP3719, which is also biocompatible and can be applied to all silicone products, i.e. room-temperature vulcanising (RTV), high consistency (HCR) and liquid silicone (LSR) products. It significantly reduces the friction of these products.
Nanoprene® and the Service Life of Tyres
Authors: Obrecht W.
Published: September 2018

Lanxess is the largest German chemicals group and supplies products to all the important world markets. The production plants of the company comprise 44 enterprises with a workforce of over 15 000 in 21 countries worldwide. According to 2007 results, the turnover of Lanxess amounted to €6.61 billion.
Processing Behaviour of High-cis Polybutadiene in Rubber Compounds
Authors: Kloppenburg H. , Hardy D. , Lucassen A. , Groß T. , Kroll J. , Lissy A.
Published: September 2018

Compounding and extrusion are critical steps in the production of rubber compounds of a reliable quality within a given timeframe and hence at a reasonable cost. The materials used - including the rubber types -are varied in order to obtain improvements in product performance. One of the most important of the synthetic rubbers is neodymium polybutadiene (NdBR) which, because of its exceptional microstructure and macrostructure, offers outstanding properties. Through the use of high-cis NdBR, marked improvements have been obtained in end products in terms of dynamic performance and good fatigue and wear characteristics. At the same time, however, the processing behaviour of this type of rubber requires adjustments to be made at the compounding and extrusion stage. This can lead to problems in the handling of the milled sheet and profiles, resulting for example in severe surface roughness or die swell. In extreme cases the benefits of NdBR can be masked altogether if no adjustments are made to the processing stages.

This paper presents countermeasures to improve the processability of NdBR by adapting the compounding and extrusion conditions to its specific requirements. The ratio of viscosity and elasticity is specific to each type of rubber and therefore requires individual adjustment of the processing conditions. We show that under appropriately adjusted conditions, even using NdBR grades with the highest molecular weights (e.g. Buna CB22), short compounding times and smooth milled sheets and extrusion profiles with a glossy surface can be obtained. Under these conditions neodymium polybutadiene rubbers provide a basis for an ideal combination of excellent material properties and improved processing behaviour.

The positive characteristics of NdBR are retained when it is used in blended rubbers such as an SSBR/BR blend. The rules regarding the optimisation of process conditions for pure NdBR systems apply here too.
Polymer Nanocomposites and their Structure and Properties. A Review
Authors: Sokolova Yu.A. , Shubanov S.M. , Kandyrin L. B. , Kalugina E.V.
Published: September 2018

This paper presents a review of the literature on polymer nanocomposites and their properties and structure. Different types of nanofiller and the properties of composites based on them are examined. Also, the principal problems associated with the creation of materials of this kind are set out – uniform distribution of the nanofiller in the polymer matrix and the guarantee of effective load transfer from matrix to filler. The current main methods for uniform dispersion of nanofillers in the polymer matrix are described: selection of the optimum mixing conditions, in situ polymerisation, and chemical modification of nanofiller particles.
Influence of Different Climatic Conditions on the Main Properties of Medium-pressure Polyethylene of Radio Engineering Designation
Authors: Dzhafarov A.S.
Published: September 2018

The results of climatic tests and the results of assessing the light resistance and moisture resistance of medium-density polyethylene are examined.
Investigating Polymer Blends Based on Chlorosulphonated Polyethylene and Ternary Ethylene–propylene Rubber by Pulsed Nuclear Magnetic Resonance
Authors: Sukhanov P.P. , Perukhin M.Yu. , Arkhireev V.P.
Published: September 2018

Pulsed nuclear magnetic resonance (NMR) was used to study the molecular mobility in polymer blends based on chlorosulphonated polyethylene and an ethylene–propylene rubber containing monomer blocks of different structure. The conducted investigation confirmed the hypothesis concerning the possible existence of separate regions of compatibility of copolymers in the blend.
The Use of Nearfield IR Spectrometry to Assess the Degree of Crosslinking of Polyethylene PEX Tubes
Authors: Stepanova K.A. , Ivanov A.N. , Kalugina E.V. , Samoilov S.V.
Published: September 2018

For the first time, nearfield IR spectroscopy was used to assess the degree of crosslinking of HDPE in the actual process of tube production.
Mechanical Properties of Polyvinyl Chloride Plastisols Containing New Flame Retardants
Authors: Plotnikova G.V. , Kuznetsov K.L. , Malysheva S.F. , Udilov V.P. , Seleznev V.Yu. , Belogorlova N.A. , Kuimov V.A.
Published: September 2018

New organophosphorus compounds based on elemental phosphorus were investigated as flame retardants for plasticised polyvinyl chloride.
Theory of Adhesion of Solutions of High-molecular-weight Compounds and its Practical Application. 2. Features of the Adhesion of Concentrated Solutions of Polymers to Fibre and Metal Substrates
Authors: Dolomatov M.Yu. , Timofeeva M.Yu.
Published: September 2018

A semi-empirical physicochemical theory of adhesion is proposed, describing adhesion in a wide range of concentrations in non-ideal media with strong intermolecular interaction.
Electrophysical Properties of a Copolymer of Maleic Anhydride and Styrene-α-octene
Authors: Kuliev M.M. , Ismaiilova R.S. , Mamedova S.A.
Published: September 2018

The electrical properties of a ternary copolymer of maleic anhydride, styrene, and α-octene were investigated.
Investigation of the Thermal Stability of Melts of Silanol-crosslinked Polyethylene Composites
Authors: Markov A.V. , Ivanov V.V. , Kuleznev V.N. , Krivolapova O.V. , Persits V.G.
Published: September 2018

A report is given on the effect of tin-containing catalysts on silanol-crosslinked polyethylene.
Nanosized Zinc Oxide Particles and Binary Layered Metal Hydroxides as Effective Components of Flame-retarding Systems for Plasticised Polyvinyl Chloride
Authors: Pravednikova O.B. , Dutikova O.S. , Satina N.A. , Sertsova A.A. , Karelina I.M. , Gal'braikh L.S.
Published: September 2018

In the present work, investigations were made of the efficiency of the heat-stabilising effect of new flame-retardant systems using nanosized metal-containing components with the aim of producing materials of reduced flammability, smoking capacity, and breakdown-product toxicity. As a result of the conducted investigations it was established that the best fireproofing characteristics are possessed by a PVC composite containing ammonium salt of amino-tris-methylene phosphonic acid and zinc oxide with 50 nm particles. The oxygen index of the indicated composite was 27.5%.
Adhesive Composite Based on Amidolysis Products of Polyurethanes
Authors: Sadykova L.Sh. , Spiridonova R.R. , Bakirova I.N. , Kochnev A.M.
Published: September 2018

Adhesive composites based on the amidolysis products of polyurethanes of grades SKU-OM, SKU-6, and SKU-PFL-100 and block polyurethane foam under the action of ε-caprolactam were produced and investigated.
Adhesion Properties of a Combined “Paper (Cardboard)–polyethylene” Material. Investigation of the Surface Energy Characteristics
Authors: Anan'ev V.V. , Chalykh A.E. , Bannikova O.A.
Published: September 2018

The surface properties of paper were investigated by wetting, and the energy characteristics and homogeneity of properties before and after its surface treatment with a “corona” discharge and gas combustion products were determined.
Comparative Analysis of the Relaxation Properties of Virgin and Recycled Polypropylene
Authors: Golovanov A.V. , Popova M.N. , Markov V.A. , Kovriga O.V. , Askadskii A.A.
Published: September 2018

The thermomechanical and relaxation properties of virgin and recycled polypropylene are presented. A comparative analysis is made of the stress relaxation parameters in the linear and non-linear region of mechanical behaviour, which were determined using a specially written computer program.
Self-degradable Polymeric Materials
Authors: Ukhartseva I.Yu.
Published: September 2018

An analytical review is given of industrially produced biodegradable polymeric materials.
Trends in the Development of the Polyethylene Terephthalate Market Worldwide and in Russia
Authors: Genis A.V.
Published: September 2018

In this review, features of the polyester (PETP) market are studied, the structure of PETP consumption worldwide is given, and the distribution of food-packaging PETP and polymer fibre production between the main regions of the world is reported. The preferential development of polyester bottle production in countries of Europe and North America is substantiated, and also the leading place taken by Asia in the production of polyester fibres and threads. A list is given of the main companies and the capacities of existing units producing polyester fibres and threads and food packaging in the United States, Europe, and Asia.

The prospects for the development of the recycled PETP market are analysed, and the expediency of expanding its production is shown. The main areas of application are given. Features of the market for PETP and PETP-based products in countries of the CIS and in Russia are investigated. The geography of Russian imports and exports of PETP is given, and also a list of newly commissioned enterprises.
Modification of the Properties of Low-density Polyethylene with Organic Additives
Authors: Kuliev M.M.
Published: September 2018

An investigation was made of the effect of organic additives and a constant magnetic field on the charge state and dielectric, antistatic, and mechanical properties of films of LDPE and LDPE-based composites.
Synthesis of Multicomponent Copolymers for the Microencapsulation of Liquid Hydrocarbons
Authors: Serdyuk V.A. , Shevchuk O.M. , Tokarev V.S.
Published: September 2018

Copolymers of acrylonitrile were investigated. The influence of the monomer ratio on the physical and physicochemical properties was established.
Hydrolytic Degradation of Biopolymer Systems Based on Poly-3-hydroxybutyrate. Kinetic and Structural Aspects
Authors: Boskhomdzhiev A.P. , Bonartsev A.P. , Ivanov E.A. , Makhina T.K. , Myshkina V.L. , Bagrov D.V. , Filatova E.V. , Bonartseva G.A. , Iordanskii A.L.
Published: September 2018

The aim of the present work is to record and compare long-term kinetic curves of the hydrolytic degradation of polymer systems: bacterial poly-3-hydroxybutyrate (POB), its copolymer with hydroxyvalerate, and also a composite mixture of POB and polylactide (PLA). To monitor the degree of hydrolytic degradation, use was made of the total weight loss of the specimen and the change in the viscosity-average molecular weight (MW). Atom force microscopy was used to assess the surface state of POB films. It was shown that the rate of hydrolytic degradation depends on the incubation medium (the nature of the buffer), temperature, the chemical composition of the biopolymer, and its molecular weight. Atom force microscopy confirmed that, along with volumetric processes of POB hydrolysis, surface hydrolysis of the polymer also occurs.
Pressing of Glass-fabric Laminates
Authors: Simonov D.V. , Ogon'kov V.G. , Afoshina E.V.
Published: September 2018

An examination was made of the theoretical principles of the process of pressing glass-fabric laminates. The main factors influencing the process and the quality of the material obtained were determined. The influence of the properties of the binder on the production of a stable, dipped glass fabric was studied. On the basis of the experimental work carried out, the optimum conditions for the processes of dipping and pressing glass-fabric laminates were determined. The results of the work have been used on new equipment introduced at the “Elektroizolit” CJSC. A considerable saving of energy resources and solvents has been achieved.
Non-ionogenic Dispersions in the Production of Fibroporous Polymer Composites
Authors: Blieva M.V. , Andrianov G.P.
Published: September 2018

An examination is made of the effect of synthetic tanning agents on the colloid-chemical properties of non-ionogenic dispersions of polymers when the latter are used in the production of fibroporous composite materials.
Effect of the Electret Charge of Polyethylene–starch Composites on their Biodegradability
Authors: Galikhanov M.F. , Minnakhmetova A.K. , Zhigaeva I.A. , Deberdeev R. Ya.
Published: September 2018

The influence of the state of polymeric materials on the process of their biodegradation was studied. The biodegradation of polyethylene–starch composites increases in intensity with increasing starch content.
Influence of the Molecular Characteristics of Epoxy Oligomers and their Blends on their Rheological Properties
Authors: Surikov P.V. , Trofimov A.N. , Kokhan E.I. , Simonov-Emel'yanov I.D. , Shcheulova L.K. , Kandyrin L.B.
Published: September 2018

An investigation was made of the influence of the molecular characteristics of industrial bisphenol-A epoxy oligomers of grades DER-330, ED-20, ED-16, and ED-8, and the molecular characteristics of their blends, on their rheological properties. It was shown that the viscosity of the oligomers and their blends is connected with the content of low-molecular-weight fraction. A procedure is proposed that makes it possible, by changing the fractional composition, to produce a blend of epoxy oligomers with a given viscosity.
Impregnation of Large Glass-fibre-reinforced Cellular Plastics
Authors: Bukharov S.V. , Kryukov A.M. , Volkov V.S. , Sadikova N.A. , Shul G.S.
Published: September 2018

An examination is made of features of technology for producing large glass-fibre-reinforced cellular plastics that ensures, at a given thickness of the cellular pack, the optimum content of binder and the required combination of physicomechanical properties of the glass-fibre-reinforced cellular plastics formed.
Effect of Chlorinated Water on Peroxide-crosslinked Polyethylene PEX-a
Authors: Gorbunova T.L. , Gaevoi N.V. , Gerasimov K.V. , Chalykh A.E. , Kalugina E.V.
Published: September 2018

An investigation was made of the effect of hot chlorinated water on the physicochemical properties of peroxide-crosslinked polyethylene PEX-a. It was shown that, even in the harshest conditions of treatment with disinfectant (the concentration of sodium hypochlorite was increased 10-20-fold by comparison with the accepted standards for potable water supply), direct chlorination (interaction of PE with chlorine) of PEX-a pipes does not occur.
The Modification of Epoxy Binder EDT-10
Authors: Sidorov O.I. , Milekhin Yu.M.
Published: September 2018

Research has been conducted into the modification of epoxy binder EDT-10 and of polymer composites based on this resin. The methods chosen for modification of binder EDT-10 were a physical action (vibration) and physicochemical modification using small additions of oligoether and an accelerator of the curing of epoxy oligomers.
Structure Formation and Abnormalities of the Kinetics of Sorption of Water and Ethyl Alcohol by Cellulose Acetate and Cellulose Hydrate
Authors: Belokurova A.P. , Gerasimov V.K. , Shcherbina A.A. , Arkad'eva Yu.E. , Chalykh A.E.
Published: September 2018

An investigation was made of the kinetics of sorption of water, ethyl alcohol, and their blends by cellulose hydrate and cellulose diacetate. It was shown that the systems are characterised by abnormally extreme kinetics of swelling, which is independent of the nature of the solvent. In this work, repeated, cyclic swelling–drying processes were carried out; it was established that the degree of swelling decreases with an increasing number of cycles. By means of IR spectroscopy and hydrostatic weighing in ethyl alcohol it was established that, during swelling, there is an increase in the density and degree of crystallinity of the polymer. That is, rearrangement of the structure of the polymer occurs, leading to complete ordering of the mutual disposition of the fragments of the macromolecular chains.
The Dynamics of a Free Jet of Solutions of Polysulphone and Polydiphenylene Phthalide in an Electrostatic Field
Authors: Gulyaev A.I. , Rykonov V.A. , Tenchurin T.Kh. , Filatov Yu.N.
Published: September 2018

An investigation was made of the dependences of change in the radius, velocity, velocity gradient, and acceleration of a liquid thread along the longitudinal coordinate on the viscosity of the solution, the volume flow rate of the solution, and the electrostatic field strength. An attempt was made to establish the relationship between the rheological properties of polymer–solvent systems and the real velocities, accelerations, and strains in a Taylor cone.
Investigation of the Stability of a “Polymethacrylic Acid–Polyethylene Glycol” Interpolymer Complex in the Process of Synthesis
Authors: Pashkina E.P. , Lobaeva T.S. , Kobyakova N.K. , Chervyakova G.N. , Eruslanova M.N.
Published: September 2018

The methods of differential thermal and thermogravimetric analysis using electron scanning microscopy were used to study the stability of a “polymethacrylic acid–polyethylene glycol” interpolymer complex in the process of synthesis. It was shown that, during drying of the polycomplex, uncontrolled heat generation is possible, resulting from the crystallisation of excess polyethylene glycol and the aggregation of polycomplex particles in the absence of moisture owing to change in the nature of the autohesion interaction of particles.
Features of the Copolymerisation of Sodium N-(Meth) Acryloylaminoalkyl Carboxylates with Acrylonitrile and Acrylamide in Aqueous Solutions
Authors: Shirshin K.V. , Sivokhin A.P. , Kazantsev O.A. , Igolkin A.V.
Published: September 2018

The “special” nature of processes of copolymerisation of sodium N-(meth)acryloylaminoalkyl carboxylates with acrylonitrile and acrylamide in aqueous solutions is shown. The effects of the influence of the initial concentration of monomers and initiators on the composition of the products of copolymerisation of sodium salt of N-acryloylaminoacetic acid with acrylonitrile are found and explained.
Polymerisable Composite for the Colouring of Contact Lenses
Authors: Ryabinina M.Yu. , Pashkina E.P. , Kobyakova N.K. , Fidler S.Kh. , Kivaev A.A.
Published: September 2018

This work is devoted to improving the composition and synthesis conditions of a polymerisable colouring composite intended for applying the design to cosmetic contact lenses by tampo printing. In the course of the investigations, the optimum concentrations of inhibitor, of molecular weight modifier, and of adhesion promoter, guaranteeing that the required properties of the composite are achieved, were established.
The Development of Rapidly Curing Adhesive Compounds for the Repair of Equipment in the Field at Sub-Zero Temperatures
Authors: Aronovich D.A. , Khamidulova Z.S. , Vetrova A.M. , Rogacheva I.P. , Zaitova N.V. , Klenovich O.I.
Published: September 2018

A study was made of reactive acrylic oligomers, initiating systems, and fillers for creating subzero-cure adhesive composites. The physicomechanical properties of the materials developed are given.
Structure and Thermal Degradation of Materials Based on a Copolymer of Vinyl Alcohol with Vinyl Acetate and Polyhydroxybutyrate
Authors: Shibryaeva L.S. , Ol'khov A.A. , Kuznetsova E.A. , Vlasov S.V. , Iordanskii A.L.
Published: September 2018

An examination is made of the effect of polyhydroxybutyrate on the structure, thermal oxidation, and thermal degradation of blends based on a copolymer of vinyl alcohol with vinyl acetate.
Crosslinked and Structurally Coloured Polycarbonate Siloxanes
Authors: Kopylov V.M. , Ivanova V.L. , Raigorodskii I.M. , Kovyazin V.A. , Kireev V.V.
Published: September 2018

Crosslinked block polycarbonate siloxanes (B-PCSs) with a gel fraction yield of up to 92 wt% were obtained by hydrosilylation and photopolymerisation, respectively, by the vinyl and methacrylate groups in B-PCSs. In the process of photocrosslinking, the strength properties of films of B-PCSs increase by 15–20% by comparison with non-crosslinked specimens. B-PCSs with chemically bound phenyl- and amine-type dyes were synthesised by a two-stage method: by reactions of hydroxy and amine groups of the dye with chloroformate groups of diphenylolpropane with subsequent polycondensation of the reaction mixture with bis-phenolsiloxanes. Investigation by electron spectroscopy in the visible region of the spectrum of crosslinked structurally coloured B-PCSs showed that, during crosslinking, there is no change in their spectral characteristics by comparison with the initial linear coloured copolymers.
The Synthesis of Phenol–Formaldehyde Copolymers Based on Phthalide-Containing Diphenol
Authors: Machulenko L.N. , Sereeva A.S. , Nechaev A.I. , Salazkin S.N. , Komarova L.I. , Petrovskii P.V.
Published: September 2018

Phthalide-containing diphenol 3-phenyl-3-(21,51-dihydroxyphenyl)phthalide was synthesised for the first time by the interaction of o-benzoylbenzoic acid chloride with hydroquinone in a dioxane solution in the presence of catalyst ZnCl2. Interaction of a mixture of the synthesised diphenol and phenol in different weight ratios (from 5:95 to 50:50) with formaldehyde in the presence of catalytic quantities of ammonia produced phenol–formaldehyde cooligomers of the resol resin type and heat-resistant crosslinked polymers based on them.
Aramid Pulp for the Reinforcement of Thermoplastic Elastomers
Authors: Müller K. , Reußmann T. , Lützkendorf R. , Schmitt M.
Published: September 2018

Aramid pulp offers excellent potential for effective reinforcement of thermoplastic elastomers such as polyamides because of its highly fibrillated fibre structure and correspondingly large surface area. However, the disadvantage of aramid pulp is that it is not free-flowing and so cannot be metered effectively. For that reason continuous metering in processes such as compounding is virtually impossible. However, research and development work at TITK has resulted in a way of processing aramid (AR) pulp to obtain prepregs which are suitable for metering. Results obtained by compounding meterable pulp with PA 6 and composite properties achieved by injection moulding are described below.
Prospects of Improving the Technological Effectiveness of Combining the Components of Reinforced Thermoplastics
Authors: Golovkin G.S.
Published: September 2018

An examination is made of the latest methods for solving the urgent problem of increasing the solidity of thermoplastics (so-called monolithisation) by filling them with continuous fibres. Data on the reduction in the residual porosity and on the increase in the mechanical properties of these plastics are given.
Complexing of Polyacrylic and Polymethacrylic Acids with Poly-p-Vinylcaprolactam
Authors: Baranovskii V.Yu. , Vasileva P.O.
Published: September 2018

Viscometry, pH-metry and IR spectroscopy were used to investigate the interaction of polyacrylic and polymethacrylic acids with poly-N-vinylcaprolactam in aqueous solution. It was shown that, with poly-N-vinylcaprolactam, poly acids form an interpolymer complex of equimolar composition in terms of base mole units. Complexing is due to the hydrogen bonds between undissociated carboxyl groups of polyacids and oxygen atoms of amide groups in the poly-N-vinylcaprolactam. Complexes of poly acids with poly-N-vinylcaprolactam are more stable than complexes between the same poly acids and poly-N-vinylpyrrolidone on account of stronger hydrophobic interaction in the former case.
Investigating the Sensitivity of Thermal Analysis Methods to Glass Transition
Authors: Foreman J. , Sauerbrunn S.R. , Marcozzi C.L.
Published: September 2018

To determine the glass transition temperature Tg of amorphous polymers, five thermal analysis methods are used: differential scanning calorimetry (DSC), modulated DSC (MDSC(tm)), thermomechanical analysis (TMA), dynamic mechanical analysis (DMA), and dielectric analysis (DA). In each of these types of analysis, the Tg is determined from the change in one of the properties of the substance during glass transition. Therefore, the relative sensitivity of the different methods to determination of Tg depends greatly on the nature of the substance under investigation, and also on the experimental conditions, e.g. the heating rate. In the present investigation, data on the glass transition temperature of a standard amorphous thermoplastic that were obtained by the five conventional thermal analysis methods are compared. The results obtained reflect the types of problem that may arise. The experimental data set out below were obtained on TA Instruments series Q instruments ( www.intertech-corp.ru ).
Effect of Solvents on the Decomposition of Hydroperoxides and Reactions of Phenoxyl Radical Loss
Authors: Makitra R.G. , Midyana G.G. , Bazilyak L.I. , Zaikov G.E.
Published: September 2018

The influence of the properties of the medium on the rate of radical processes can be generalised by means of multiparameter equations taking into account the different properties of the solvents. The applicability of this approach is demonstrated for the case of the decomposition of tetralin hydroperoxide and lithium salt of tert-butyl hydroperoxide, and also the recombination of phenoxyl radicals. In all cases, an important role is played by the cohesive energy density of the solvents, i.e. their self-association.
The Effectiveness of Polar Modifying Additives for Polyethylene
Authors: Sirota A.G. , Bugorkova V.S.
Published: September 2018

This article examines the potential for optimisation of the distribution of polar functional additives in polyethylene to improve its thermal stability, cracking resistance, hydrophilic properties, adhesion capacity and other features.
Investigation of the structure and properties of modified polyepoxy vinyl ester networks
Authors: Smirnov Yu.N. , Muradian V.E. , Shatskaia T.E. , Beliaeva E.A. , Kosolapov A.F. , Son-Pei Tang
Published: September 2018

This article investigates the molecular-topological structure and strength properties of polyeopxy vinyl ester resin modified with polyurethane rubber before and after being held in an HF solution.
Study of the Aerodynamics of a Regular Liner Made of Polymer Mesh Fabric
Authors: Trusov M.S. , Pushnov A.S. , Bulatov S.N. , Vitkovskaia R.F. , Shishov V.I.
Published: September 2018

This article presents the results of aerodynamic tests on a new liner made from polymer mesh. The potential for use of this liner for evaporation cooling processes is demonstrated.
The Synthesis of New Aromatic Polyazomethine Esters and the Investigation of their Properties
Authors: Zalova T.V. , Borukaev T.A.
Published: September 2018

New polyazomethine esters were obtained by low-temperature polycondensation on the basis of aromatic dialdehydes and 4,4′-diaminotriphenylmethane in an aprotic solvent. The polymers synthesised are low-melting substances with good solubility in organic solvents and concentrated sulphuric acid. The optimum conditions for the production of high-molecular-weight polyazomethine esters were determined, and their mesomorphic properties were investigated.
The Behaviour of Three-Dimensional Polymers of Oligoester Acrylates under Conditions of Uniaxial Elongation
Authors: Sivergin Yu.M. , Kireeva S.M.
Published: September 2018

The influence on the stress–strain diagram of three-dimensional polymers of oligoester acrylates of the chemical nature of the groups (ester, carbonate, amide, urethane, and urea) in the oligomer block and the length of the latter was established.
Wood–Mineral–Polymer Composites
Authors: Raspopov L.N. , Matkovskii P.E.
Published: September 2018

The results of the work make it possible to recycle renewable waste of plant origin and certain mineral highly dispersed substances, and may be used in the furniture and building sectors of industry. An empirical approach is proposed to describing the physicomechanical properties of the composites considered, based on three constituent volume fractions: (1) rigid, slightly deforming volume fractions; (2) thermoplastic volume fractions; (3) cavities.
Influence of the Structural Parameters on the Biodegradation of Poly-3-Hydroxybutyrate and Composites Based on it
Authors: Tertyshnaya Yu.V. , Khvatov A.A. , Likhachev A.N. , Popov A.A.
Published: September 2018

An investigation has been made of the probability of blends of poly-3-hydroxybutyrate (PHB) and ethylene–propylene rubber and 100% PHB being contaminated by micromycete species. Aspergillus flavus, Trichoderma viride, and Penicillium chrysogenum were most aggressive. The thermophysical characteristics after exposure to organic acids were determined.