bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological evolution of polypropylene/polystyrene blends in a twin‐screw extruder
Authors: Wu Yang , Jing Shaowei , Gu Qun , Li Binyao 
Published: August 2010

AbstractThe effects of the blend composition and rotation speed on the morphological evolution of polypropylene (PP)/polystyrene (PS) blends were investigated in a twin‐screw extruder. When PS was the major component, the rate of melt and the rate of dispersion played final roles in the morphological development of the polymer melts. However, when PP was the major component, the rate of dispersion and the rate of coalescence played key roles. A high tendency to coalesce occurred at a high rotation speed and/or a high content of the dispersed phase. When the PP/PS blend composition was close to 1, a cocontinuous morphology was observed to transmute into a coarse one with increasing rotation speed. Attempts were made to correlate the morphology and mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Evaluation of the corrosion barrier properties of nano‐reinforced vinyl chloride/vinyl acetate coatings
Authors: Calhoun M. , Ludwick A. , Mahmoud M. , Aglan H. 
Published: August 2010

AbstractA poly(vinyl chloride/vinyl acetate) copolymer (VYHH) with and without multiwalled carbon nanotubes (MWCNTs) as reinforcements were used as a coating for steel substrates to evaluate their barrier properties against corrosion. Electrical impedance and thermal properties of the coatings were evaluated. The coatings were formulated with 0.1% MWCNT, by weight. Neat and nano‐filled VYHH was used to coat polished, degreased steel substrates via a dipping method. The substrates were either dipped once, for a target coating thickness of 30–40 μm, or twice for a target coating thickness of 60–75 μm. The coated and uncoated control samples were submerged in a tank with a 5% NaCl solution for a 45‐day period. Electrochemical impedance spectroscopy (EIS) revealed that coating thickness plays a role in corrosion resistance. EIS also showed that nano‐reinforced VYHH had the highest charge transfer resistance within its coating thickness. Fourier transform infrared spectroscopy (FTIR) indicated that hydrolysis occurred in the single coatings for both the neat and nanoreinforced coatings. Differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA) both showed that the addition of MWCNTs improved the thermal stability of the VYHH. DSC thermograms revealed that the thermal properties of the nano VYHH were largely unchanged after 45 days of submersion as compared with the unaged nano VYHH. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and photopolymerization of 2‐(acryloyloxy)ethyl piperidine‐1‐carboxylate and 2‐(acryloyloxy)ethyl morpholone‐4‐carboxylate
Authors: Xiao Ming , Li Zhenfeng , Nie Jun 
Published: August 2010

AbstractTwo low‐viscosity monomers, 2‐(acryloyloxy)ethyl piperidine‐1‐carboxylate (AEPC II) and 2‐(acryloyloxy)ethyl morpholone‐4‐carboxylate (AEMC), were synthesized with a non‐isocyanate route. The photopolymerization kinetics was monitored by real‐time infrared spectroscopy with a horizontal sample holder. The results indicated that AEPC II and AEMC had high ultraviolet curing rates and final double‐bond conversions, which could reach 90 and 95%, respectively. The glass‐transition temperatures of AEPC II/urethane acrylate resin (1/4 w/w), AEMC/urethane acrylate resin (1/4 w/w), and isobornyl acrylate/urethane acrylate resin (1/4 w/w) mixtures were 37.5, 45.6, and 57°C, respectively. The crosslink density of the AEMC/urethane acrylate resin (1/4 w/w) mixture was lower than that of the isobornyl acrylate/urethane acrylate resin (1/4 w/w) mixture. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Modeling processing of silicone rubber: Liquid versus hard silicone rubbers
Authors: Hernández‐Ortiz Juan P. , Osswald Tim A. 
Published: August 2010

AbstractThe processing of hard and liquid silicone rubbers (LSR) are compared by means of modeling and simulation. The curing process for both, hard and liquid silicone, are modeled using the auto‐catalytic Kamal‐Sourour model and a nonlinear regression method is used to find the kinetic parameters. The fitted kinetic model is then combined with the heat balance equations to simulate real processing conditions. Both resins are compared in terms of process performance and consistency of the final part. The results show that even though hard silicone rubbers are less expensive resins, its processing conditions present several issues of consistency and quality control when compared with LSR. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119:1864–1871, 2011
Kinetics study of isothermal nicotine release from poly(acrylic acid) hydrogel
Authors: Adnadjevic Borivoj , Jovanovic Jelena , Lazarevic Natasa 
Published: August 2010

AbstractThe isothermal kinetic of the release of nicotine from a poly(acrylic acid) (PAA) hydrogel was investigated at temperature range from 26°C to 45°C. Specific shape parameters of the kinetic curves, the period of linearity and saturation time were determined. The change in the specific shape parameters of the kinetic curves with temperature and the kinetic parameters of release of nicotine Ea and ln A were determined. By applying the “model fitting” method it was established that the kinetic model of release of nicotine from the PAA hydrogel was [1 − (1 − α)1/3] = kMt. The limiting stage of the kinetics release of nicotine was found to be the contracting volume of the interaction interface. The distribution function of the activation energy was determined and the most probable values of activation energies of 25.5 kJ mol−1 and 35 kJ mol−1 were obtained. Energetically heterogeneity of the interaction interface was explained by the existence of the two different modes of bonding the nicotine molecules onto the hydrogel network by hydrogen bond and electrostatic forces. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Aggregate structure and effect of phthalic anhydride‐modified soy protein on the mechanical properties of styrene‐butadiene copolymer
Authors: Jong Lei 
Published: August 2010

AbstractThe aggregate structure of phthalic anhydride (PA) modified soy protein isolate (SPI) was investigated by estimating its fractal dimension from the equilibrated dynamic strain sweep experiments. The estimated fractal dimensions of the filler aggregates were less than 2, indicating that these particle aggregates have a distorted or broken two‐dimensional sheet‐like structure. The results also indicated that the aggregate structure has a greater effect on the composite reinforcement than the overall aggregate size. Tensile strength, elongation, Young's modulus, and toughness of hydrolyzed/modified soy composites are comparable with those of carbon black reinforced composites at 10–15% filler fraction. The moduli of PA‐modified SPI composites were less sensitive to the pH of the composite preparation compared to the unmodified SPI. The composites prepared at acidic pH, with lower filler fraction, or filled with hydrolyzed/modified SPI are more elastic and less fatigue. The composites of PA‐modified SPI had better recovery properties when prepared at acidic instead of alkali pH. PA‐modified hydrolyzed SPI composites prepared at acidic pH showed a similar recovery property to that of carbon black reinforced composites, but with greater shear elastic moduli. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Study on the effective process parameters influencing styrene and acrylonitrile grafting onto seeded polybutadiene latex
Authors: Abbasi F. , Agah A. M. , Mehravar E. 
Published: August 2010

AbstractA series of experiments were designed and conducted to determine the significance of process parameters in the grafting of styrene and acrylonitrile onto polybutadiene seeds in a semicontinuous emulsion copolymerization system. The significances of the parameters were obtained by comparing the variance ratios, or F values, with F‐distributions. The significance level of each test (α‐value) was obtained by variance analysis. The important process parameters in industrial polymerization processes are usually monomer‐to‐polymer ratio, initiator type and concentration, chain‐transfer agent, and reaction temperature. The target responses were final monomer conversion, grafting degree, grafting efficiency, gel percent, and viscosity‐average molecular weight of free styrene‐acrylonitrile (SAN). The analysis of variance indicated that cumene hydroperoxide as the initiator and reaction temperature had strong effects on the graft structure. Moreover, free SAN molecular weight was significantly affected by the monomer/polymer ratio and cumene hydroperoxide and n‐dodecyl mercaptan as chain‐transfer agents. The raspberry‐like morphology of grafted acrylonitrile‐butadiene‐styrene (ABS) particles and phase separation within the particles were confirmed by transmission electron microscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Study on the properties of ethylene‐vinyl acetate rubber vulcanizate filled with superfluous magnesium hydroxide/methacrylic acid
Authors: Yu Haiyang , Zhang Yong , Chen Shuguo , Ren Wentan , Hoch Martin , Guo Sharon 
Published: August 2010

AbstractEthylene‐vinyl acetate rubber (EVM) vulcanizates cured by dicumyl peroxide (DCP) with excellent mechanical properties were obtained by adding superfluous magnesium hydroxides (MH)/methacrylic acid (MAA). Different factors such as the DCP content and MH content were investigated to reveal their effects on the properties of the MH/MAA‐filled EVM vulcanizates. The formulation of DCP of 2 phr, MH of 60 phr, and MAA of 5 phr is recommended for the EVM vulcanizates with excellent mechanical properties. The stress relaxation and stress softening behavior of MH/MAA‐filled EVM vulcanizates were studied. The stress relaxation and stress softening became faster and more obvious with increasing MH content. The hot air aging resistance of EVM vulcanizates filled with different fillers such as silica and high abrasion furnace were compared, and the MH/MAA‐filled EVM vulcanizates had the best aging resistance at 40‐phr filler content. The MH/MAA‐filled EVM vulcanizates had excellent flame retardancy due to the high MH content. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Dispersion and mechanical properties of a nanocomposite with an organoclay in an ionomer‐compatibilized LDPE matrix
Authors: Santamaría P. , Eguiazabal J. I. , Nazabal J. 
Published: August 2010

AbstractWidely dispersed low density polyethylene (LDPE) based nanocomposites (Nc's) were obtained in the melt state thanks to their compatibilization with a zinc ionomer of poly(ethylene‐co‐methacrylic acid) (Pema‐Zn). The variables probed were the ionomer and organoclay content ranging from 0 to 20%, and from 0 to 10%, respectively. The TEM images showed that the organoclay is widely exfoliated. Furthermore, we report for the first time that the organoclay is concentrated in irregular zones. Taking into account the compatibility between MMT and the ionomer, it is plausible that the ionomer clusters are also concentrated in the organoclay‐rich regions. This heterogeneous microstructure has a positive effect on the mechanical properties since the Nc's are ductile, and the modulus increases were among the largest reported for LDPE, attaining a 160% increase with a 10% montmorillonite (MMT) content. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Sorption of binary mixtures of toluene + lower aliphatic alcohols C1 – C6 in low‐density polyethylene
Authors: Randová A. , Bartovská L. , Hovorka Š. , Izák P. , Friess K. , Janků J. 
Published: August 2010

AbstractSorption gravimetric and volumetric techniques performed at 25°C and at atmospheric pressure were employed to study the preferential and total sorptions from binary liquid mixtures of toluene + lower aliphatic alcohols (C1 – C6) in a high‐pressure low‐density polyethylene membrane and the volume of the swollen membrane. Toluene was preferentially sorbed in all six systems. The total sorbed amount increased from pure alcohol to pure toluene. The experimental volume of the swollen membrane was compared with that calculated under the assumption that interactions between the polymer and liquid mixture were negligible. The composition of the binary liquid mixture sorbed in the polymer as a function of the composition of the bulk solution surrounding the membrane is presented. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The unidirectional glass fiber reinforced furfuryl alcohol for pultrusion. II. Correlation of processing parameters for optimizing the process
Authors: Chen Chin‐Hsing , Chen I‐Ken 
Published: August 2010

AbstractUnidirectional glass fiber reinforced furfuryl alcohol (FA) composites have been prepared by the pultrusion processes. The optimum processing parameters of the glass fiber reinforced FA composites by pultrusion has been studied. The effects of the optimum processing parameters on the properties (flexural strength, flexural modulus, notched Izod impact strength, glass transition temperature (Tg), dynamic shear storage modulus (E'), shrinkage ratio, and roughness) investigated including die temperature, pulling rate, postcure temperature and time, and filler type and content. Results show that the pultruded composites possessed various optimum pulling rates at different die temperatures. On the basis of the DSC diagram, the swelling ratio and the mechanical properties of pultruded composites, the optimum die temperature can be determined. The mechanical properties and Tg increase at a suitable postcure temperature and time. Furthermore, the properties which decrease due to the degradation of pultruded composites for a long postcure time will be discussed. The mechanical properties of pultruded composites reach a maximum value at various filler content corresponding to the talc and calcium carbonate, respectively, and then decreased. When the fillers are added to the pultruded glass fiber reinforced FA composites, the shrinkage ratio of composites become smaller, and the surface of composites became smooth. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
UV‐curable nanocomposites containing zirconium vinylphosphonate or zirconia
Authors: Macarie Lavinia , Plesu Nicoleta , Iliescu Smaranda , Popa Adriana , Ilia Gheorghe 
Published: August 2010

AbstractUV‐cured nanocomposite films were prepared from acrylic monomer and two types of nanomaterial: zirconium vinylphosphonate and zirconia, in the presence of a photoinitiator. The films were characterized by FTIR, SEM, and AFM. FTIR spectra showed the disappearance of band assigned to the CC group both of monomer and zirconium vinylphosphonate by polymerization and the presence of the phosphonate group in polymer. The influence of zirconium vinylphosphonate and zirconia content on thermooxidative degradation of polymeric films was studied by thermogravimetry. SEM and AFM images showed that nanomaterials are dispersed in polymer matrix with no macroscopic phase separation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Optimization of the process variables for the synthesis of starch‐based biodegradable resin using response surface methodology
Authors: Hong Fu‐Liang , Peng Jinchyau , Lui Wai‐Bun 
Published: August 2010

AbstractResponse surface methodology (RSM) was used to analyze the effect of different additives glycerol level (X1) and plasticizer level (X2) on the objective (water solubility index, water absorption index, and Max. loading) attributes of a cornstarch/PHBV blended composite. A rotatable central‐composite design (CCD) was used to develop models for the objective responses. The experiments were run at barrels temperatures 160, 160, 165, and 165°C, respectively, with screw speed 40 rpm and complete feeding (filling ratio = 1). Responses were most affected by changes in plasticizer level (X2) and to a lesser extent by glycerol level (X1). Individual contour plots of the different responses were overlaid, and regions meeting the predicted optimum water solubility index of 4.34%, water absorption index of 4.55 g gel/g dry wt, and Max. loading of 370.06 N were identified at the plasticizer level of 21.06 g, and the glycerol level of 96.11 mL, respectively. These predicted values for optimum process conditions were in good agreement with experimental data. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Narrow size‐distribution poly(methyl methacrylate) nanoparticles made by semicontinuous heterophase polymerization
Authors: Aguilar J. , Rabelero M. , Nuño‐Donlucas S. M. , Mendizábal E. , Martínez‐Richa A. , López R. G. , Arellano M. , Puig J. E. 
Published: August 2010

AbstractThe effect of surfactant (sodium dodecyl sulfate) concentration on particle size, molar masses, glass transition, and tacticity of poly(methyl methacrylate) (PMMA) nanoparticles synthesized by semicontinuous heterophase polymerization under monomer‐starved condition at constant monomer feeding rate is reported. Starved conditions are confirmed by the low amount of residual monomer throughout the reaction and by the fact that the instantaneous polymerization rate is similar to the feeding rate of monomer. Under these conditions, polymer particles in the nanometer range (20–30 nm) were obtained with narrow size distribution (1.07 < Dw/Dn < 1.18), depending of surfactant concentration. Final particle size diminishes as the surfactant concentration is increased. Glass transition temperatures and syndiotactic content (54%–59%) of the produced polymers are substantially higher than those reported for commercial and bulk‐made PMMA. Molar masses are much lower than those expected from termination by chain transfer to monomer, which is the typical termination mechanism in 0–1 emulsion and microemulsion polymerization of this monomer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of evolved interactions in poly(butylene succinate)/fumed silica biodegradable in situ prepared nanocomposites on molecular weight, material properties, and biodegradability
Authors: Vassiliou Alexandros A. , Bikiaris Dimitrios , El Mabrouk Khalil , Kontopoulou Marianna 
Published: August 2010

AbstractPoly(butylene succinate) (PBSu)/fumed silica nanocomposites were prepared in situ by condensation polymerization. TEM micrographs verified that the dispersion of the nanoparticles was homogeneous in the PBSu matrix, while some small agglomerates were also formed at a higher SiO2 content. 13C NMR spectra affirmed that the hydroxyl end groups of PBSu could form covalent bonds with the surface silanol groups of SiO2. These interactions affected the molecular weight of the prepared nanocomposites. At low concentrations the SiO2 nanoparticles acted as chain extenders, increasing the molecular weight of PBSu, while at higher loadings they resulted in extended branching and crosslinking reactions, leading to gradually decreased molecular weights. Silica nanoparticles acted as nucleating agents, increasing the crystallization rate of PBSu. However, the degree of crystallinity was slightly reduced. Tensile strength and Young's modulus were significantly increased with increasing SiO2 content. The presence of the nanoparticles resulted in reduced enzymatic hydrolysis rates compared to pure PBSu, attributed to the smaller available organic surface, due to the incorporation of SiO2, and to the existence of branched and crosslinked macromolecules. Dynamic mechanical and rheological properties were also extensively studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
In situ formation of nanocomposites based on polyethylene and silica nanospheres
Authors: Zapata Paula , Quijada Raúl , Benavente Rosario 
Published: August 2010

AbstractPolyethylene nanocomposites containing silica nanospheres, synthesized by the sol–gel method, were produced via in situ polymerization. The silica nanospheres were added together with the catalytic system [metallocene catalyst and methylaluminoxane (MAO) as cocatalyst] directly to the reactor and used for the polymerization of ethylene. The polymerization activity increased slightly in the presence of 1 wt % silica nanospheres in comparison to the homogeneous polymerization sans filler. The Young's modulus of the nanocomposites increased 19–25% without a significant decrease in the elongation at break with respect to the neat polyethylene. The polymer particle morphology was also significantly improved with the incorporation of silica nanospheres. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Melt shear viscosity of PP/Al(OH)3/Mg(OH)2 flame retardant composites at high extrusion rates
Authors: Liang J. Z. , Yang J. , Tang C. Y. 
Published: August 2010

AbstractThe melt apparent shear viscosity (ηa) of polypropylene (PP) composites filled with aluminum hydroxide [Al(OH)3] and magnesium hydroxide [Mg(OH)2] was measured by means of a capillary rheometer under experimental conditions of temperature ranging from 180 to 200°C and apparent shear rate varying from 10 to 2 × 103 s−1, to identify the effects of the filler particle content and size on the melt viscosity. The results showed that the melt shear flow of the composites obeyed the power law and presented pseudoplastic behavior. The dependence of ηa on temperature was consistent with the Arrhenius equation. The sensitivity of ηa for the composite melts to temperature was greater than that of the unfilled PP, and weakened with increasing apparent shear rate. The ηa increased linearly with an increase of the weigh fraction of the flame retardant, especially in the low apparent shear rate region. The ηa of the composites decreased slightly with an increase of particle size of flame retardant. Moreover, the variation for the ηa with particle size of flame retardant was much less than with apparent shear rate under these test conditions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Sensing behaviors of polymer/carbon nanotubes composites prepared in reversed microemulsion polymerization
Authors: Li Zhenhua , Li Qiang , Shang Songmin , Li Liang , Yang Xiaoming , Yu Xianghua , Yan Guoping 
Published: August 2010

AbstractPolystyrene/carbon nanotubes composites were readily prepared by reversed microemulsion polymerization. Compared with the composites prepared by solution mixing, the uniform dispersion of carbon nanotubes in polymer matrix could be obtained more easily and the thermal and electrical properties of the as‐prepared composites were also enhanced. The as‐prepared composites were deposited onto a microelectrode array to fabricate a vapor sensor. The response for different organic vapors was evaluated by monitoring the change in the resistance of the composites upon exposure to various gases. The change in resistance was of the order of about 103 for the composites prepared by reversed microemulsion polymerization. The chemical sensors based on the composites prepared by reversed microemulsion polymerization presented excellent reproducibility and reversibility in response. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Entrapment of urease in poly(1‐vinyl imidazole)/poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) network
Authors: Şenel Mehmet , Çevik Emre , Abasıyanık M. Fatih , Bozkurt Ayhan 
Published: August 2010

AbstractIn this article, urease was immobilized in a conducting network via complexation of poly(1‐vinyl imidazole) (PVI) with poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPS). The preparation method for the polymer network was adjusted by using Fourier transform infrared (FTIR) spectroscopy. A scanning electron microscope (SEM) study revealed that enzyme immobilization had a strong effect on film morphology. The proton conductivity of the PVI/PAMPS network was measured via impedance spectroscopy, under humidified conditions. The basic characteristics (Michealis‐Menten constants, pHopt, pHstability, Topt, Tstability, reusability, and storage stability) of the immobilized urease were determined. The obtained results showed that the PAA/PVI polymer network was suitable for enzyme immobilization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011