bluuebunny/crossref_metadata_2025_split huggingface dataset:
Free radical polymerizations of some vinyl monomers in carbon dioxide fluid
Authors: Wang Zi , Yang Ya Jun , Dong Qing Zhi , Hu Chun Pu 
Published: July 2008

AbstractThe effect of pressure ranging from ambient atmosphere to 28.5 MPa on the free radical polymerizations of methyl methacrylate (MMA) in carbon dioxide (CO2) was investigated and discussed. The poly(methyl methacrylate) (PMMA) with high molecular weight was synthesized at quite high conversion of MMA in the polymerization at or below 9.2 MPa, as compared to those polymerized under 11.8–28.5 MPa. A phase transition behavior of MMA‐CO2 binary mixture from homogeneous state to vapor‐liquid equilibrium (VLE) state was observed below 10.51 MPa. In such a VLE system, almost all MMA was found to exist in the liquid phase with higher concentration than that in homogenous system. Thus, the fast polymerization rate of MMA and high molecular weight of PMMA could be related to the VLE state of MMA/CO2 under low pressure. Similar phenomena were also observed in the polymerization systems of styrene and vinyl acetate in CO2, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Properties of solid solutions of poly(ethylene oxide)/epoxidized natural rubber blends and LiClO4
Authors: Chan C. H. , Kammer H. W. 
Published: July 2008

AbstractSolid solutions of blends of poly(ethylene oxide) (PEO) and epoxidized natural rubber (ENR) comprising 12 wt % of LiClO4 were studied. Two glass transition temperatures, corresponding to the Tgs of the constituents, confirm immiscibility of the polymers over the entire composition range. It turns out that the Tgs of both polymers slightly increase after addition of salt to the blends. This shift is approximately constant over the whole range of blend composition. Accordingly, Tg measurements reveal that the salt dissolves to approximately equal relative amounts in the two phases. The degree of crystallinity of PEO in blends with ENR descends only to a minor extent with ENR content. However, addition of salt leads first to decreasing crystallinity and second this decrease becomes more pronounced with the addition of ENR. It shows that under these experimental conditions the salt content in PEO increases as compared to ENR. As one expects, the rate of isothermal crystallization does not change in blends as long as PEO is in excess. The situation changes again when salt is added. The rate decreases in a certain range of crystallization temperatures when ENR is added, demonstrating that salt is favorably dissolved in PEO. Conductivity was measured in polymers comprising different salt concentrations. A power‐law dependence of conductivity on salt concentration was found. It results that the mobility of charge carriers in PEO exceeds that of ENR by five orders of magnitude. Therefore, the conductivity in blends is primarily governed by PEO as long as PEO is in excess. Conductivity measurements reveal again that salt is preferably dissolved in PEO. The distribution coefficient is estimated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Miscibility, thermal, and mechanical studies of hydroxypropyl methylcellulose/pullulan blends
Authors: Prasad P. , Guru G. S. , Shivakumar H. R. , Rai K. Sheshappa 
Published: July 2008

AbstractMiscibility of blends of hydroxypropyl methylcellulose (HPMC) and Pullulan in common solvent water were studied by viscometry, ultrasonic, density, and refractometric methods at 30 and 40°C. Further the blend films of HPMC and Pullulan were prepared by solution casting method and characterized by Fourier transform IR spectroscopy (FTIR), scanning electron microscopy, tensile measurements, thermogravimetric, and differential scanning calorimetric (DSC) methods. Using the viscosity data, interaction parameters were computed and it suggests that the blend is miscible when the HPMC content is more than 50% in the blend. The change in temperature had no significant effect on the miscibility of HPMC/Pullulan blends. The semimiscibility is confirmed by ultrasonic velocity, density, and refractometric methods. The specific intermolecular interactions of hydrogen bonding type of the blends were investigated by DSC and FTIR. The miscible compositions of HPMC/Pullulan blend showed improved thermal and mechanical properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Biodegradable plastics from animal protein coproducts: Feathermeal
Authors: Sharma Suraj , Hodges James N. , Luzinov Igor 
Published: July 2008

AbstractThis work describes the properties of plastics made from partially denatured proteins produced by the animal coproduct (rendering) industry and these plastics' fabrication. Specifically, plastic samples from partially denatured feathermeal protein were successfully produced by a compression‐molding process. The modulus (stiffness) of the material obtained was found to be comparable with that of commercial synthetic materials, such as polystyrene, but was found to have lower toughness characteristics, which is a common phenomenon among plastics produced from animal and plant proteins. A reversible stress–strain property was observed over the yield region. Plastic‐forming conditions for undenatured animal proteins, such as albumen and whey proteins, were also formulated for fabricating plastics out of these proteins' blends with feathermeal proteins. The resultant plastic samples that were developed of biomacromolecular blends, such as feathermeal/whey and feathermeal/albumen, demonstrated improved mechanical properties, specifically tensile strength, when compared with neat plastics from feathermeal proteins. The values for the stiffness of the feathermeal/whey blends deviated from simple mixing rule and showed a synergistic effect. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Ethylene polymerization catalyzed by diamide complexes of Ti(IV) and Zr(IV)
Authors: Carone Carlos L. P. , Fim Fabiana C. , Bisatto Rubens , Jahno Vanusca D. , Lemos Cristóvão , Basso Nara R. S. , Einloft Sandra , Galland Griselda Barrera 
Published: July 2008

AbstractIn this research, we describe the application of the complexes o‐C6H4(NSiMe3)2ZrCl2 (1), o‐C6H4(NSiMe3)2TiBr2 (2), o‐C6H4(NSiMe3)2TiCl2 (3), C2H4(NSiMe3)2ZrCl2 (4), in the ethylene polymerization with different Al/M ratios and temperatures. These complexes presented significant catalytic activities in the presence of methyaluminoxane (MAO) as cocatalyst and toluene as solvent, producing high molecular weight linear polyethylenes. Zirconium complexes were more active at 60°C and titanium complexes at 40°C. Zirconium complex (1) showed the best values of activity (347 kg PE/mol Zr h atm) for Al/Zr ratio of 340 and 60°C of temperature. In ethylene‐1‐hexene copolymerization, the best result was also reached with catalyst 1, at the same conditions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, cure kinetics, and thermal properties of the Bis(3‐allyl‐2‐cyanatophenyl)sulphoxide/BMI blends
Authors: Anuradha G. , Sarojadevi M. , Sundararajan P. R. 
Published: July 2008

AbstractA novel allyl functionalized dicyanate ester resin bearing sulfoxide linkage was synthesized. The monomer was characterized by Fourier Transform Infrared (FT‐IR) Spectroscopy, 1H‐, and 13C Nuclear Magnetic Resonance (NMR) spectroscopy and elemental analysis. The monomer was blended with bismaleimide (BMI) at various ratios in the absence of catalyst. The cure kinetics of one of the blends was studied using differential scanning calorimetry [nonisothermal] and the kinetic parameters like activation energy (E), pre‐exponential factor (A), and the order of the reaction (n) were calculated by Coats‐Redfern method and compared with those calculated using the experimental Borchardt‐Daniels method. The thermal stability of the cured dicyanate, BMI, and the blends was studied using thermogravimetric analyzer. The initial weight loss temperature of dicyanate ester is above 380°C with char yield of about 54% at 800°C. Thermal degradation of BMI starts above 463°C with the char yield of about 68%. Inclusion of BMI in cyanate ester increases the thermal stability from 419 to 441°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Kinetic study of atom transfer radical polymerization of methyl methacrylate in ionic liquids
Authors: Zhang Hongyan , Zhang Yumei , Liu Weiwei , Wang Huaping 
Published: July 2008

AbstractThe kinetics of methyl methacrylate (MMA) homopolymerization performed by atom transfer radical polymerization (ATRP) is investigated in detail using ethyl‐2‐bromopropionate (EPN‐Br) as initiator, CuBr as catalyst, and pentamethyldiethylenetriamine (PMDETA) as ligand in ionic liquids (ILs) and acetonitrile. ILs in this research covered two different substitutional imidazolium cations and anions including halogen and halogen‐free ones. The typical cations include 1‐butyl‐3‐methylimidazolium, 1‐ethyl‐3‐methylimidazolium and the typical anions include bromide, tetrafluoroborate. The effects of solvents, temperature, and reaction ingredients ratios on the polymerization kinetics are all investigated in this article and the apparent energy of activation (ΔE) calculated for the ATRP of MMA in 1‐butyl‐3‐methyl‐imidazolium tetrafluoroborate is 6.95 KJ/mol. The number‐average molecular weights (Mn) increase linearly with conversion but are much higher than the theoretical values. It is probably due to the low concentration of deactivator at the early stage of polymerization and the lower bond energy of C‐Br in PMMA‐Br than that in EPN‐Br. Moreover, the catalyst is easily separated from the polymer and the regenerated catalyst is reused for more than three times. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Amino‐functionalized multiple‐walled carbon nanotubes‐polyimide nanocomposite films fabricated by in situ polymerization
Authors: Hu Yizhe , Wu Liping , Shen Jianfeng , Ye Mingxing 
Published: July 2008

AbstractFor the preparation of high‐quality polymeric carbon nanocomposites, it is required that carbon nanotubes are fully compatible with matrix polymers. For this purpose, amino‐functionalized multiple‐walled carbon nanotubes (a‐MWNTs) were synthesized. The a‐MWNTs/polyimide nanocomposite films were prepared through in situ polymerization. According to the spectroscopic characterizations, the a‐MWNTs were homogeneously dispersed in the nanocomposite films as the acid‐functionalized MWNTs. The mechanical properties of the polyimide composite were also studied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of water‐soluble oligosalicylaldehyde‐sulfanilic acid and its Cu(II), Co(II), Pb(II) complexes
Authors: Turac Ersen , Surme Yavuz , Sahmetlioglu Ertugrul , Varol Ramazan , Narin Ibrahim , Toppare Levent 
Published: July 2008

AbstractThis work presents the synthesis and characterization of a new water‐soluble oligophenol derivative, 4‐(2‐hydroxybenzylideneamino)benzenesulfanilic acid (OSAL‐SA) and its metal complexes. The chemical structure of the water‐soluble polymer was characterized by nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopies and thermogravimetric analyses (TGAs). Pb(II), Cu(II), Co(II) complexes of the polymer were also synthesized in methanol. Characterizations of water insoluble polymer‐metal complexes were performed by FTIR, flame atomic absorption spectroscopy, and TGA. The conductivity measurements of OSAL‐SA and polymer–metal complexes were carried out by the four‐probe technique. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Pilling in man‐made cellulosic fabrics, part 1: Assessment of pilling formation methods
Authors: Bui Huong Mai , Ehrhardt Anelise , Bechtold Thomas 
Published: July 2008

AbstractDespite the pills appear similarly in fabric surfaces, their structure and mechanism of formation are distinct depending on material categories and handling conditions. The lyocell and viscose knitted fabrics were abraded with short cycles in the wet state as an assessment method for pilling formation called rapid pilling test (RPT). The samples were immersed in different wetting agents and subsequently padded before short abrasion in Martindale tester. The results were compared with long abrasion, besides 5–25 cycles of washing and drying (W‐D). The samples were rated and these results were correlated with the changes in the physical parameters obtained in the dry and wet state. The correlation showed the feasibility of RPT in wet state with short‐abrasion cycles, in lieu of long cycles and W–D cycles. Furthermore, the image analysis of single pills formed by different methods and the inner/outer pill structure may reflect the pilling mechanism and yield a comprehensive view of the whole process. Instead of conventional Martindale test, the easy‐handling RPT can be applied for cellulosic fabrics, in which wet samples are abraded in short cycles fulfilling two important demanding factors during test performance: test of material in the wet state and reduced testing time. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of fine Ni particles and their shielding effectiveness for electromagnetic interference
Authors: Gong Chunhong , Duan Yuping , Tian Juntao , Wu Zhishen , Zhang Zhijun 
Published: July 2008

AbstractFine Ni particles with sphere‐like architecture were synthesized via a wet chemical route in distilled water. The resulting fine Ni particles and/or commercial microsized Ni particles were then added to a mixed resin solution to fabricate resin‐based conductive composites. The shielding effectiveness (SE) of the resultant conductive composites for electromagnetic interference was measured as a function of nickel mass fraction. The results indicated that the SE values of the two kinds of Ni‐containing resin‐based composites increased with increasing loading of Ni filler. Moreover, the fine Ni particles, in the absence of any protective agents, were liable to aggregate for the sake of decreasing surface energy, which could be well avoided by ultrasonic disposal. The resin‐based conductive composites containing a low concentration (33.3 wt %) of the ultrasonically disposed fine Ni particles recorded an SE value as much as above 22 dB in a frequency range of 130 MHz to 1.5 GHz, which could not be realized for the composites filled with microsized nickel particles unless the mass fraction of the Ni filler in this case was as high as 50.0 wt %. In other words, the ultrasonically disposed fine Ni particles could be used as efficient lightweight filler for shielding of electromagnetic interference. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Zeolite catalyzed glycolysis of poly(ethylene terephthalate) bottle waste
Authors: Shukla S. R. , Palekar Vikrant , Pingale Navnath 
Published: July 2008

AbstractPolyethylene terephthalate (PET) bottle waste was depolymerized using excess of ethylene glycol (EG) in the presence of zeolites, β‐zeolite and Y‐zeolite as transesterification catalyst. The glycolysis reaction was carried out under reflux in excess of ethylene glycol up to 8 h. The product of glycolysis was mainly the virtual monomer, bis(2‐hydroxyethyl) terephthalate (BHET) admixed with dimer as residue. The BHET was obtained in pure crystalline form. Influence of the reaction time, PET : EG ratio, type, and concentration of catalyst on the yield of the glycolysis products was investigated. The characterization of the purified monomer was carried out by elemental analysis, melting point, IR spectroscopy, DSC, and NMR. The yield of BHET monomer was more than 60%, which is comparable with the conventionally used heavy metal catalysts such as zinc acetate and lead acetate. This process of glycolysis of PET is economically viable and the catalysts are environment friendly. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and characterization of silanized silica gel‐supported poly(acrylic acid) network polymer and study of its analytical application as selective extractor for lead ion
Authors: Chowdhury P. , Pandit S. K. , Mandal B. 
Published: July 2008

AbstractA novel silanized silica gel (SSG)‐supported poly(acrylic acid) network polymer (ion exchanger) has been synthesized and characterized for the study of its analytical applications. The chemical nature of the ion exchanger has been elucidated with the help of FTIR, NMR, TGA, DSC, and SEM. The immobilization of the polymer network on SSG has been studied. The optimum pH range for quantitative extraction of lead was found to be 4.5–6.0. The effects of pH and stripping agent on extraction and elution of Pb(II), respectively, have been investigated. Ion exchange and break through capacity of the exchanger have been determined at room temperature. Pb(II) has been extracted quantitatively from various environmental samples. A plausible mechanism for lead ion exchange has been suggested. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Interfacial modification of high impact polystyrene magnesium hydroxide composites effects on flame retardancy properties
Authors: Chang Suqin , Xie Tingxiu , Yang Guisheng 
Published: July 2008

AbstractHigh impact polystyrene (HIPS)/magnesium hydroxide (MH) composites were prepared by melt‐blending. Two kinds of interfacial modifiers were used in this research, maleinated poly[styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene] (SEBS‐g‐MA) triblock copolymer and PS. The effects of the use levels of SEBS‐g‐MA on the flame retardancy of HIPS/elastomer/MH based on unmodified and PS‐modified surface were investigated by TEM, FTIR, and combustion tests (horizontal burning test and cone calorimetry). The combustion results showed that comparing composites containing unmodified MH, the flame retarding properties of composites containing PS‐modified MH were obviously improved. The increased performance can be explained that the PS covered on the surface of MH could further improve dispersion of the filler in matrix. Furthermore, there existed a critical thickness of interfacial boundary for optimum flame‐retarding properties in both ternary composites based MH and PS‐modified MH. When the interfacial boundary relative thickness is less than 0.53, the introduction of SEBS‐g‐MA can improve the dispersion degree, leading the improvement of flame retardancy properties. However, with the increase of interfacial boundary thickness, the SEBS‐g‐MA coating around MH acted as a heat and mass transfer barrier, leading to the reduction of flame retardancy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of branched polyacrylonitrile through self‐condensing vinyl copolymerization
Authors: Liu Qingchun , Xiong Ming , Cao Ming , Chen Yongming 
Published: July 2008

AbstractBranched polyacrylonitrile (PAN) was prepared through a self‐condensing vinyl copolymerization of acrylonitrile and 2‐(2‐bromopropionyloxy)ethyl acrylate (BPEA). The branched architecture of the product was confirmed by NMR spectra and the average degree of branching (DB) was estimated. Through a comparison of the intrinsic viscosity of the product with that of its linear analogue, the contraction factor g′ was calculated. It was found that the viscosity of the branched PAN was obviously lower that that of linear PAN. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Morphology and properties of silane‐modified montmorillonite clays and clay/PBT composites
Authors: Wan Chaoying , Bao Xujin , Zhao Feng , Kandasubramanian Bala , Duggan Matthew P. 
Published: July 2008

AbstractCommercially available organoclay (Closite 30B) was modified by using 3‐aminopropyltriethoxysilane (APS) via a silylation reaction. Sodium clay (Closite Na) was treated by APS directly as a control. Such modified clays were further melt‐compounded with polybutylene terephthalate (PBT). The morphology and properties of the modified organoclays were characterized with X‐ray diffraction (XRD), transmission electrical microscopy (TEM), Infra‐red spectroscopy, contact angle measurement, and thermogravimetric analysis (TGA). The effects of modified clays on the crystallization behavior of PBT were characterized by differential scanning calorimetry. The basal spacing of Closite Na was enlarged from 1.01 to 1.41 nm after APS treatment, indicating that the APS was intercalated into the clay intergalleries as a monolayer. The basal spacing of Closite 30B increased slightly after APS treatment, partially resulted from the reactions between the APS and hydroxyl groups on the intercalant of Closite 30B. Closite 30B was found to be exfoliated disorderly after melt‐compounded with PBT. The APS‐modified Closite 30B only dispersed as swollen elliptical clay aggregates, in which the silicate layers were orderly intercalated. TGA results showed that the decomposition temperature at 5% weight loss of Closite 30B was increased from 250 to 270°C after APS treatment. A significant increase in the degree of crystallinity of PBT was observed in the exfoliated PBT/30B composite. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Interface and mechanical properties of peroxide cured silicate nanofiber/rubber composites
Authors: Tian Ming , Cheng Lijun , Zhang Liqun 
Published: July 2008

AbstractFour representative rubber matrices with varying molecular polarity, such as SBR, NBR, EPDM, and CNBR, were reinforced by mechanical blending with γ‐(methacryloxy)proxyltrimethoxy silane (KH570) silanized natural fibrillar silicate (FS)/unmodified FS when dicumyl peroxide was used as a curing agent. The effects of the loading amount of silane coupling agent KH570 and the type of rubber matrix on the dispersion of FS as well as the FS‐rubber interfacial bonding were investigated. The mechanical properties of various rubber composites filled with unmodified FS and silanized FS individually were compared. As indicated by SEM and TEM, unmodified FS showed better dispersion in polar CNBR than in nonpolar SBR, whereas the improvement of the dispersion is more for SBR after the silanization of FS, constructing a stronger filler network. Compared with unmodified FS/rubber composites, silanized FS/rubber composites exhibited a higher interphase crosslinking network as well as a lower loss factor, indicating the improvement of the FS‐rubber interfacial bonding. The more the loading amount of KH570 was, the more the FS‐SBR bonding was improved. Similarly, the improvement of the FS‐rubber bonding was more evident in nonpolar SBR and EPDM after FS was silanized, causing the more increase in mechanical properties, relative to polar NBR and CNBR. In strong molecular polar rubber such as CNBR and NBR, the strong interfacial bonding was achieved even if FS was not silanized with KH570, so that the composites filled with unmodified FS also possessed good mechanical properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Influence of microstructure and morphology on stress–strain behavior of commercial high density polyethylene
Authors: Zahedi Mostafa , Ahmadi Mostafa , Nekoomanesh Mehdi 
Published: July 2008

AbstractIn the previous paper (Zahedi et al.,1 J Appl Polym Sci, to appear) the optimal conditions of a new modeling procedure for correlating a scalar response to an input spectrum were established. In this article the developed model is applied to correlate the stress–strain behavior of several commercial high density polyethylene samples to the spectrums of microstructure and morphology. Molecular weight and lamellar thickness distributions were considered as the input spectrums and Young modulus, stress and strain at the yield and break points were considered as the objective responses. The shape of the kernel functions over molecular weight and lamellar thickness distribution spectrums for each mechanical property gives an explanation of how different regions of the spectrums contribute to create the considered property. The simplicity of the procedure facilitates the interpretation of the complex influences and interactions of different structures and morphologies in various aspects of the mechanical performance of the samples. The proposed model can be used in designed experiments with samples of controlled microstructure and morphology to provide detailed information about the structure–property relationships. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008