bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soap‐free emulsion copolymerization of perfluoroalkyl acrylates in the presence of a reactive surfactant
Authors: Tingting Yang , Hui Peng , Shiyuan Cheng , Park In Jun 
Published: February 2007

AbstractSoap‐free emulsion copolymerization of perfluoroalkyl acrylate (FA)/methyl methacrylate (MMA)/n‐butyl acrylate (n‐BA) was carried out in the presence of sodium 2‐acrylamide‐2‐methyl propanesulfonate (AMPSNa) as a reactive surfactant and potassium persulfate (KPS) as an initiator. An analysis of the effects of concentration of AMPSNa, KPS, FA as well as polymerization temperature on the kinetic features (rate of polymerization) and colloidal characteristics (mean particle diameter, particle disperse index, particle numbers, and surface charge density) was followed. NMR, FTIR, AFM, and fluorine‐selective electrode analysis were used to characterize the composition and morphology of the FA copolymers. Both AFM analysis and contact angle measurements strongly implied that the fluorinated segments migrated to the outmost surface and created films with lower surface energy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2438–2444, 2007
Enhancement of the water repellency durability of the fabrics treated by fluorinated nanocopolymer emulsions
Authors: Huang Pei‐Yuan , Chao Yu‐Chou , Liao Yih‐Tyan 
Published: February 2007

AbstractThe fluorinated copolymer emulsions containing different monomers with the reactive groups were successfully prepared at our lab, using emulsion polymerization technique. The water repellency and the durability for the fabrics treated by fluorinated water repellents after 30 and 50 washes were measured and compared. Actually, the combination of the comonomers containing blocked isocyanate or other reactive groups after copolymerization would increase the durability of the water repellency. In addition, the blocked isocyanate crosslinking agent (Jintexguard FCN) does, indeed, substantially increase the durability also. It clearly indicates that the copolymer emulsion prepared by the reaction of fluorinated acrylate, cyclohexyl methacrylate, and 3‐chloro‐2‐hydroxy‐propyl methacrylate(Topolene M) with monomers containing blocked isocyanate group(Jintexan BIA) showed very good durability. More importantly, the combination of this copolymer and Jintexguard FCN will significantly provide excellent water repellency and durability after 50 washes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2451–2457, 2007
Migration resistant polymeric plasticizer for poly(vinyl chloride)
Authors: Lindström Annika , Hakkarainen Minna 
Published: February 2007

AbstractFlexible films of poly(vinyl chloride) (PVC) and linear or branched poly(butylene adipate) (PBA), synthesized from 1,4‐butanediol and adipic acid or dimethyl ester of adipic acid, were aged in an aqueous environment for 10 weeks to study how branching, molar mass, and end‐group functionality affect the leaching of polyester plasticizer from thin films. Principal component analysis was applied to reveal patterns and correlations between mechanical properties, material characteristics, and aging behavior. Introduction of branches in the polyester structure increased the miscibility between PVC and the polyester, resulting in improved mechanical properties and lower water absorption. Methyl ester end‐group in PBA polyester stabilized the polymeric plasticizer toward hydrolysis, and reduced the formation and migration of monomeric degradation products from the blends during aging in water. The combination of branched structure with methyl ester end‐groups resulted in a migration resistant polymeric plasticizer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2458–2467, 2007
Transient effects in dynamic modulus measurement of silicone rubber, part 2: Effect of mean strains and strain history
Authors: Warley R. L. , Feke D. L. , Manas‐Zloczower I. 
Published: February 2007

AbstractThe strain‐dependent dynamic storage modulus of a poly(dimethyl‐siloxane‐co‐methylvinyl‐siloxane‐co‐methylphenyl‐siloxane)‐based silicone elastomer (PVMQ), which is reinforced with fumed silica and crosslinked with peroxide, is investigated. The time dependence of the dynamic storage modulus on the magnitude of the mean strain at a particular test condition is investigated. The dynamic modulus results are shown to depend on the time of cycling as well as the relative magnitudes of the dynamic and mean strains. The relaxation of the force required to maintain the mean strain is observed to depend on the magnitude of the dynamic strains and the data are shown to be consistent with static stress relaxation experiments in the limit of zero dynamic strain. Recovery of the dynamic modulus from the exposure to higher strain cycling is seen to be facilitated by dynamic cycling with higher cycling strains yielding faster recovery rates. The observed phenomena are interpreted in terms of the role of entanglements in the polymer phase on the dynamic behavior of the elastomer material. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2197–2204, 2007
Influence of binding interface between active and support layers in composite PDMS membranes on permeation performance
Authors: Shi Er , Huang Weixing , Xiao Zeyi , Li Donghuai , Tang Ming 
Published: February 2007

AbstractEffect of the binding interfaces of composite polydimethylsiloxane (PDMS) membranes on their pervaporation performance was studied. The membranes were made up of PDMS as active skin layer and polysulfone (PSF) or polyamide (PA) as supporting layer. PDMS‐PSF membrane was numbered 1, and PDMS‐PA membrane numbered 2. The pervaporation experiments were carried out by using the composite membranes and dilute ethanol–water mixture. The experimental measurements for the permeation performance under various operating conditions (e.g., feed concentration and temperature) showed that the specific permeation rate of membrane 2 was over membrane 1 by seven times at least. A resistance‐in‐series model was applied to formularize the transport of the permeants. Influence of the binding interfaces between the active skin layer and support layers in these membranes on pervaporation performance was analyzed. The cross section morphology of the membranes and chemical element distribution along membrane thickness were examined by using SEM and EDS. It was found that, although the PDMS intrusion layer into PSF near the interface was only about 2 μm, it gave significant effect on the permeation performance. It implied that the resistance produced by the intrusion layer into PSF was apparently larger than that of PDMS intruding PA and over intrinsic PDMS resistance. These should be probably attributed to structures and formation of the binding interfaces. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2468–2477, 2007
Use of different size grids to control the surface chemistry of plasma‐polymerized acrylic acid films in a hybrid discharge
Authors: Dhayal Marshal 
Published: February 2007

AbstractThe surface chemistry of plasma‐polymerized acrylic acid (ppAc) films were controlled in a two‐stage (primary and processing) hybrid radio frequency (RF) discharge by changing the grid wire spacing (ds). Two regions were defined in terms of ds with respect to Debye length (λd) in the primary chamber at the grid to control the electron temperature (Te) and surface chemistry of the ppAc films deposited in the processing chamber. A higher Te (>3 eV) in the processing plasma was possible for ds > λd, whereas decreasing ds relative to λd reduced Te. X‐ray photoelectron spectroscopy was used to characterize the ppAc films deposited on a glass substrate. The ppAc films surface characterization showed the maximum proportion of carbon atoms as carboxylic/ester [C(O)OX] functionalities in C1s at the surface of films for the grid with ds ≈ λd. The proportion of carbon atoms as [C(O)OX] and COX in C1s at the surface decreased when ds decreased relative to λd. The proportion of carbon atoms as carbonyl (CO) at the film surface showed very good stability for all of the ds values explored in this study. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2219–2224, 2007
Thermal fractionation and properties of different polyethylene/wax blends
Authors: Hato M. J. , Luyt A. S. 
Published: February 2007

AbstractThe influence of paraffin‐wax type and content on the properties of its blends with HDPE, LDPE, and LLDPE was investigated. Melt‐mixing of HDPE with wax gave rise to completely miscible blends for both 10 and 20% wax contents. A wax content of 30% gave rise to a partially miscible blend. These observations were supported by the thermal fractionation (stepwise cooling) results. Melt‐mixing of LDPE with hard paraffin wax gave rise to a partially miscible blend for all wax contents investigated, while complete miscibility was observed for the 10% oxidized hard paraffin wax containing blend. Complete miscibility was observed for all the LLDPE/A1 wax blends, with A1 wax as an oxidized hard paraffin wax. This indicates possible cocrystallization of this wax with LLDPE, which was also evident from the thermal fractionation curves. LLDPE blends with hard paraffin wax were, however, partially miscible for all wax contents. All the observations were supported by the surface free energy results. It is further clear from the thermal fractionation results that the presence of wax changed the crystallization behavior of LDPE and LLDPE. Changes in the tensile properties are explained in terms of the miscibility and proposed morphologies of the blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2225–2236, 2007
Modification of rubber powder with peroxide and properties of polypropylene/rubber composites
Authors: Shanmugharaj A. M. , Kim Jin Kook , Ryu Sung Hun 
Published: February 2007

AbstractWaste tire powder was functionalized in the presence of various concentrations of allylamine and benzoyl peroxide. Fourier transform infrared spectroscopy studies confirmed the presence of allylamine on the surface of the rubber powder. The surface energy of the functionalized rubber powder revealed that the introduction of allylamine onto the rubber powder surface increased the surface activity. Improvements in the tensile strength, elongation at break, and storage modulus were observed for polypropylene/modified rubber powder/maleic anhydride grafted polypropylene, and this was attributed to an improvement in the compatibility due to the chemical interaction between the rubber powder and compatibilizer. Evidence for the reaction between the rubber surface and compatibilizer was observed in Fourier transform infrared studies. This peroxide‐initiated monomer‐grafting technique is feasible for large‐scale processes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2237–2243, 2007
Hemodialysis membranes prepared from poly(vinyl alcohol): Effects of the preparation conditions on the morphology and performance
Authors: Barzin J. , Madaeni S. S. , Pourmoghadasi S. 
Published: February 2007

AbstractPoly(vinyl alcohol) was employed for the preparation of hemodialysis membranes with and without the addition of acetic acid and poly(ethylene glycol) with the phase‐inversion process. Aqueous solutions of sodium sulfate and sodium hydroxide were chosen as coagulant baths. The performances of the membranes were estimated by the measurement of the removal of uremic toxins (urea, uric acid, and creatinine) from human blood serum. The morphologies of the membranes were investigated and correlated to the membrane performance. Increasing the poly(ethylene glycol) concentration in the polymer solutions resulted in porous, spongelike structures because of the higher polarity of the polymer solutions and the enhancement of the diffusion rate of the nonsolvent (sodium sulfate and sodium hydroxide) into the polymer solutions. The porous structures of the membranes enhanced the removal of uremic toxins. The presence of acetic acid, with greater ionization strength, resulted in higher electrostatic interactions between positive and negative ions in the coagulation baths and polymer solutions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2490–2497, 2007
Effects of stretching on crystalline phase structure and morphology of hard elastic PVDF fibers
Authors: Du Chun‐hui , Zhu Bao‐Ku , Xu You‐Yi 
Published: February 2007

AbstractThe phase characteristics and morphology of stretched hard elastic poly(vinylidene fluoride) (PVDF) fibers were investigated by X‐ray diffraction (XRD) and wide‐angle and small‐angel X‐ray scattering (WAXS and SAXS). It was indicated that α and β phases coexisted in stretched PVDF fibers, stretching assisted in α to β phase transformation. The β/α ratios of stretched PVDF fibers were affected by stretching temperature, rate, and ratio. The β phase content of stretched PVDF fibers had an abrupt increase when stretched near 70°C, and then it decreased with increasing stretching temperature. Besides, the β/α ratio of PVDF fibers increased with stretching rate and ratio. The total crystallinity of PVDF fibers did not change much even on different stretching conditions. WAXS results indicated that the unstretched and stretched PVDF fibers all exhibited three strong equatorial streaks, with d‐spacing (0.964, 0.488, and 0.439 nm) and (0.946, 0.494, and 0.480 nm), which suggested that PVDF fibers still remained the crystalline reflections of c‐axis orientation even after being stretched. The long periods of stretched PVDF fibers, calculated from SAXS curves, increased from 19.04 to 39.75nm. On the basis of these results, the β transformation mechanism of stretched PVDF fibers was also discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2254–2259, 2007
Temporal evolution of phase morphology of polypropylene/poly(ethylene octene) elastomer binary polymer blends by phase contrast microscope
Authors: Xu Xinhua , Zhu Tianbing , Yan Xueliang , Zhang Chunhuai 
Published: February 2007

AbstractBlend films of polypropylene/poly(ethylene‐octane) at various mixing times are prepared by freezing‐microtome. The temporal evolution of their phase morphologies is investigated by phase contrast microscope (PCM). The digital image analysis, which contains the analysis in both real and wave‐number space, is introduced to deal with the PCM graphs. The characteristic length, L in real space, the average domain spacing, and the average chord lengths in wave‐number space, are used to express the domain sizes of two phases. The temporal evolution of phase morphology reaches the dynamic equilibrium between breakup and coalescences of domains at the late stage of mixing. In addition, two different fractal dimensions are defined to discuss the symmetry of the distribution of dispersed phase domains and the distribution uniformity: Df for the symmetry and Dc for the uniformity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Novel hybrid of clay, cellulose, and thermoplastics. I. Preparation and characterization of composites of ethylene–propylene copolymer
Authors: Pratheep Kumar Annamalai , Pal Singh Raj 
Published: February 2007

AbstractThe present study is aimed to prepare hybrid materials by incorporating layered silicates and microcrystalline cellulose into thermoplastic polymer. Using ethylene–propylene (EP) copolymer as thermoplastic polymer matrix and maleated EP (MEP) copolymer as compatibilizer, three types of composites were prepared by (i) melt mixing of cellulose with thermoplastics [I], (ii) melt mixing of clay with thermoplastics [II], and (iii) melt mixing of cellulose with the thermoplastic clay nanocomposites [III]. They were characterized by X‐ray diffractometry (XRD), differential scanning calorimetry, thermogravimetric analysis, and Fourier transform infrared spectroscopy. Instron was used to measure the mechanical properties. The composites [II] and [III] that contain layered silicates were intercalated nanocomposites as confirmed by XRD and transmission electron microscopy. The improvement in tensile properties was observed in cellulose–fiber‐reinforced composites with increasing cellulose content. In nanocomposites [II] and [III], the tensile modulus was improved. The resistance of the cellulose composites [I] for water absorption decreased with increasing content of cellulose fibers. The incorporation of layered silicates reduced the water absorption of cellulose composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2672–2682, 2007
Surface modification of natural rubber film by UV‐induced graft copolymerization with methyl methacrylate
Authors: Anancharungsuk W. , Tanpantree S. , Sruanganurak A. , Tangboriboonrat P. 
Published: February 2007

AbstractMethyl methacrylate (MMA) was directly grafted on natural rubber (NR) or sulfur prevulcanized (SP) NR surface. The rubber sheet was primarily treated with argon plasma, followed by exposure to air for generating active functional groups. After immersing in a mixture of 30% hydrogen peroxide and MMA in ethanol and water (1 : 1), the MMA grafting took place after UV‐irradiation for 30–120 min. Results from the contact angle measurement and attenuated total reflection–Fourier transform infrared (ATR‐FTIR) spectroscopy showed that the highest amount of MMA grafting was achieved when using 13 wt % of MMA and UV irradiation time of 60 min. The tensile strength and percentage elongation at break of the modified SPNR sheet, having similar MMA grafting to that of NR, were in acceptable range as indicated in the standard glove's test (ASTM D3577). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2270–2276, 2007
Physical properties of water‐borne polyurethane blended with chitosan
Authors: Lin Y. H. , Chou N. K. , Wu W. J. , Hsu S. H. , Whu S. W. , Ho G. H. , Tsai C. L. , Wang S. S. , Chu S. H. , Hsieh K. H. 
Published: February 2007

AbstractWater‐borne polyurethanes based on 4,4‐diphenylmethane diisocyanate, poly(butylene adipate), and chain extender N‐methyldiethanolamine (MDEA) that provided tertiary amine groups were synthesized. The polyurethane–chitosan (PU/CS) blends can be dissolved in the acetic acid and cast into films. The mechanical properties including tensile strength and elongation, as well as the water absorption and thermal properties of the PU/CS films were evaluated. The tensile strength increased with the increased amount of chitosan, but the elongation decreased accordingly. The chitosan in the blends promoted the water absorption. Chitosan was more thermally‐stable than PU, as shown in the thermal gravity analysis. Chitosan also had higher crystallinity, as demonstrated by differential scanning calorimetry. The blends were partial compatible mixtures, based on the data obtained from a dynamic mechanical analysis. Biocompatibility test was conducted utilizing immortalized rat chondrocytes (IRC). After IRC were seeded onto the PU/CS films for 1.5 and 120 h, the number of cells was counted and the morphology of cells was observed by light microscopy and scanning electron microscopy. Blends containing 30% chitosan had more cells attached initially. However, the blends containing more than 70% chitosan appeared to promote the cell proliferation. IRC were round on PU/CS films with more PU, but spread when the chitosan content in blends was higher. Overall, PU/CS films with more chitosan had better mechanical properties as well as biocompatibility. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2683–2689, 2007
Synthesis, characterization, and in vitro degradation of star‐shaped P(ε‐caprolactone)‐b‐poly(L‐lactide)‐b‐poly(D,L‐lactide‐co‐glycolide) from hexakis [p‐(hydroxymethyl)phenoxy]cyclotriphosphazene initiator
Authors: Yuan Weizhong , Yuan Jinying , Huang Xiaobin , Tang Xiaozhen 
Published: February 2007

AbstractHexaarmed star‐shaped hydroxyl‐terminated poly(ε‐caprolactone) (PCL) was successfully synthesized via the ring‐opening polymerization of ε‐caprolactone (CL) with hexakis[p‐(hydroxymethyl)phenoxy]cyclotriphosphazene initiator and stannous octoate catalyst in bulk. The star‐shaped PCL with hydroxy end groups could be used as a macroinitiator for block copolymerization with L‐lactide (L‐LA). The star‐shaped triblock copolymer was synthesized by above‐mentioned hydroxyl‐terminated star‐shaped diblock PCL‐b‐PLLA, D,L‐lactide (D,L‐LA), and glycolide (GA). IR, 1H NMR, and GPC analysis showed that the star‐shaped block copolymers were successfully synthesized and the molecular weights and the unit composition of the star‐shaped block copolymers were controlled by the molar ratios of monomer to initiator. The triblock copolymer presented a three‐phase structure, namely, PCL crystalline, PLLA crystalline, and D,L‐PLAGA amorphous domains, which made the triblock copolymer different from the diblock copolymer and star‐shaped PCL in crystallizability and thermal behaviors. Then, the in vitro degradation behaviors of the copolymers were investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2310–2317, 2007
Use of recycled polystyrene with polyurethane in polymer network compositions
Authors: Leite André Leonardo , Kloss Juliana , Trindade Eduardo Marques , Barbosa Ronilson Vasconcelos , Cestari Antônio Reinaldo , Fragoso Eunice , Zawadzki Sônia Faria 
Published: February 2007

AbstractPostconsumer polymer recycling is a technology that involves many fields of science. The production of plastics has increased in recent years, and the products have many applications. Because of this, waste plastics are also increasing, causing many environmental problems due to the slow rate of natural decomposition of synthetic polymers. Polymer chemistry and process engineering are good tools for decreasing the problems caused by inappropriate polymer disposal. The subject of this work was the preparation of polymer networks based on recycled polystyrene (in the crystal form, PS; or in the expanded form, EPS) and polyurethane. The compositions were prepared by reaction between the polyurethanes (PU) components in the presence of recycled PS or EPS dissolved in the styrene monomer containing benzoyl peroxide as a free radical initiator. 1,4‐butanediol (BDO) was used as chain extender for PU network. The compositions were characterized by the evaluation of mechanical properties, thermogravimetric analysis, and morphological analysis. The PS or EPS concentration used in the mixtures was in the 1–5 wt % range. The addition of PS or EPS changed the mechanical behavior as well as the final morphology of the compositions. The use of the PS/PU or EPS/PU network systems is a way of decreasing PS or EPS discards decreasing this environmental problem. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2714–2719, 2007
Conversion analysis of acrylated hyperbranched polymers UV‐cured below their ultimate glass transition temperature
Authors: Schmidt Lars Erik , Leterrier Yves , Schmäh Daniel , Månson Jan‐Anders E. , James David , Gustavsson Eva , Svensson Lennart S. 
Published: February 2007

AbstractThe photo‐curing behavior of reactive blends of dipentaerythritol penta/hexaacrylate (DPHA) with an acrylated hyperbranched polyester and an acrylated hyperbranched polyether was investigated by means of photo differential scanning calorimetry. The chemical conversion data was analyzed using an autocatalytic model with close attention paid to the influence of composition, UV intensity, and vitrification. The autocatalytic model was found to be relevant to describe autoacceleration and diffusion controlled reaction stages, as long as the polymers were not vitrified. It was shown that the reaction order and the autocatalytic exponent were independent of UV intensity, whereas the rate constant showed strong intensity dependence, and the maximal conversion showed weak intensity dependence. A criterion for vitrification onset was proposed as the occurrence of a third stage in the conversion process. The ultimate conversion was found to be 0.16 higher than the conversion at vitrification for all investigated multifunctional acrylates independent of composition and UV intensity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2366–2376, 2007