bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graft copolymerization of soybean protein isolate and methacrylic acid
Authors: Yang Cheng , Song Xiaoqing , Sun Chao , Chen Mingqing , Xu Yulan , Liu Xiaoya , Ni Zhongbin 
Published: August 2006

AbstractGraft copolymers of soybean protein isolate (SPI) and methacrylic acid (MAA) were prepared in an 8 mol/L urea aqueous solution with ammonium persulfate (APS) as an initiator, β‐mercaptoethanol as an unfolding agent for SPI, and a chain‐transfer agent. Evidence of grafting was obtained by the comparison of the Fourier transform infrared and NMR spectra of SPI with those of the SPI‐grafted MAA copolymer [SPI‐g‐poly(methacrylic acid) (PMAA)]. A possible copolymerization mechanism of SPI and MAA was determined, and the copolymerization rate equation was derived. The effect of β‐mercaptoethanol content, APS content, and reaction temperature on the graft copolymerization was studied by the determination of the grafting parameters, including grafting percentage and grafting efficiency. Dynamic laser light scattering was used to investigate the effect of the pH value on the hydrodynamic radius of SPI and the grafted SPI aggregate in aqueous solution. The average hydrodynamic radius of SPI‐g‐PMAA aggregate was much smaller than that of the SPI aggregate at about the isoelectric point of SPI and a high pH value, and the hydrodynamic radius distribution of the SPI‐g‐PMAA aggregate was narrower than that of the SPI aggregate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4023–4029, 2006
Synthesis and characterization of polycarbonates by melt‐phase interchange reactions with alkylene and arylene diphenyl dicarbonates
Authors: Al‐Hamouz Othman Charles S. , Sweileh Bassam A. , Al‐Salah Hassan A. 
Published: August 2006

AbstractAlkylene and arylene diphenyl dicarbonates were used as monomers for the preparation of polycarbonate polymers. The diphenyl dicarbonates were first prepared from dihydroxy compounds and phenyl chloroformate. The polycarbonates were then prepared by the melt‐phase polycondensation of these diphenyl dicarbonates with dihydroxy compounds as monomers. The same polycarbonates were also synthesized by a different route involving the polycondensation of a different arylene or alkylene diphenyl dicarbonates with bisphenol A diphenyl dicarbonate to give another series of polycarbonates. The process involved precondensation under a stream of nitrogen and then melt polycondensation at a high temperature and low pressure. The prepared polycarbonates were characterized by inherent viscosity measurement, Fourier transform infrared spectroscopy, 1H‐NMR and 13C‐NMR spectroscopy, and powder X‐ray diffraction. The thermal properties of the polycarbonates were studied with differential scanning calorimetry and thermogravimetric analysis. With alkylene or arylene diphenyl dicarbonates as monomers, the polycondensation reactions led to the formation of polycarbonates with inherent viscosities of up to 0.68 dL/g and with high thermal stability. The glass‐transition temperature values of the polycarbonates were in the range 24–130°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3597–3609, 2006
Characterization of sulfonated poly(styrene–divinylbenzene) and poly(divinylbenzene) and its application as catalysts in esterification reaction
Authors: Coutinho Fernanda M. B. , Rezende Simone M. , Soares Bluma G. 
Published: August 2006

AbstractPolymeric supports based on divinylbenzene (DVB) were prepared by aqueous suspension polymerization in presence or absence of styrene (S), using toluene and n‐heptane as diluents of the monomers. Poly(S–DVB) and poly(DVB) were sulfonated with sulfuric acid in presence of 1,2‐dichloroethane. The influence of the morphological structure of the supports and as a consequence of the catalyst on the esterification reaction of acetic acid with n‐butanol was evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3616–3627, 2006
Effect of clay on immiscible morphology of poly(butylene terephthalate)/polyethylene blend nanocomposites
Authors: Wu Defeng , Zhou Chixing , Zhang Ming 
Published: August 2006

AbstractPolymer blend nanocomposites containing poly(butylene terephthalate) (PBT), polyethylene (PE), and organoclay were prepared by direct melt compounding. Their immiscible morphologies weree investigated using electronmicroscopy, X‐ray diffraction, and parallel plate rheometry. The PE domain sizes were reduced when the polar PBT phase was continuous (PBT/PE = 60/40) because the clay tactoids effectively prevented the coalescence of the dispersed PE domains. However, when the PBT component presented domains dispersed in the rich PE matrix (PBT/PE = 40/60), the addition of clay (>2 wt %) changed the phase morphology into a novel cocontinuous one, which was further confirmed by rheological measurements. The existence of clay tactoids led to a sharp enhancement in the viscosity of the PBT phase, changing the viscosity ratio between the PBT and PE phases remarkably, which may have promoted the phase inversion. As a result, clay had significant effects on the morphology of the polymer blend. © 2006 Wiley Periodicals Inc. J Appl Polym Sci 102: 3628–3633, 2006
Hydrogel‐forming agar‐graft‐PVP and κ‐carrageenan‐graft‐PVP blends: Rapid synthesis and characterization
Authors: Prasad Kamalesh , Mehta Gaurav , Meena Ramavatar , Siddhanta A. K. 
Published: August 2006

AbstractGrafting of agar and κ‐carrageenan with polyvinylpyrrolidone (PVP, average molecular weight 10,000 D) in an aqueous medium at a pH of about 7 produced agar‐graft‐PVP and κ‐carrageenan‐graft‐PVP blends capable of forming hydrogels. The reaction was carried out with microwave irradiation in the presence of a water‐soluble initiator, potassium persulfate. Optimum microwave irradiation conditions for obtaining hydrogels of the grafted products were achieved. The structural characteristics and thermal stability of the grafted blends were studied by Fourier transform infrared, 13C‐NMR, and thermogravimetric analyses. Appearance of new IR bands at 1661, 1465, and 1426 cm−1 in the grafted products indicated the insertion of PVP into the polysaccharide structure. Powder X‐ray diffraction studies revealed the enhanced crystallinity in the products compared to in the control polysaccharides as well as PVP. Agar and κ‐carrageenan were grafted to a considerable degree, with 62.5 E % and 125 G % for agar‐graft‐PVP and 65.5 E % and 131 G % for κ‐carrageenan‐graft‐PVP. Optical micrographs of the grafted blends indicated considerable changes in the morphology of the agar and the κ‐carrageenan, substantiating the X‐ray diffraction data. A plausible mechanism for the crosslinking of PVP to agar and κ‐carrageenan is proposed. These hydrogels exhibited enhanced water‐holding capacity despite weaker gel strength than that in the respective control polysaccharides. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3654–3663, 2006
Pseudoreinforcement effect of multiwalled carbon nanotubes in epoxy matrix composites
Authors: Zhuang G. S. , Sui G. X. , Sun Z. S. , Yang R. 
Published: August 2006

AbstractThe carbon nanotube possesses outstanding physical properties. Theoretically, adding carbon nanotubes into a polymer matrix can remarkably improve the mechanical properties of the polymer matrix. In the present work, a series of composites was prepared by incorporating multiwalled carbon nanotubes (MWNTs) into an epoxy resin. The influences of MWNT content and curing temperature on the flexural properties of the epoxy resin were investigated. The results showed that a very low MWNT content should be used to ensure homogeneous dispersion of MWNTs in the epoxy matrix. A higher MWNT content may lead to deteriorated mechanical properties of the composites because of the aggregation of MWNTs. A decline in the flexural properties of the neat epoxy resin with increasing curing temperature was found. However, under the same curing conditions, improvement in flexural properties was observed for the composite with the low MWNT content and a mild curing temperature. The improvement was far beyond the predictions of the traditional short‐fiber composite theory. In fact, this improvement should be attributed to the retarding effect of MWNTs on the curing reaction of epoxy matrix. Therefore, the improvement in the flexural properties was only a pseudoreinforcement effect, not a nano‐reinforcement effect of the MWNTs on the epoxy resin. Perhaps, it is better for MWNTs to be used as functional fillers, such as electrical or thermal conductive fillers, than as reinforcements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3664–3672, 2006
A novel method to prepare a metallocene adduct catalyst with low moisture sensitivity
Authors: Wang Hongtao , Chen Wei , Zheng Gang , Li Hangquan 
Published: August 2006

AbstractA novel method to prepare a three‐constituent adduct of metallocene Cp2MCl2/2LiCl/THF is proposed. The adduct catalyst can be easily prepared without salt separation and recrystallization and possessed a low moisture sensitivity and a high stability. Measurements with NMR and XPS showed that specific intermolecular interactions exist among the three components, by which the stability of the adduct was increased. The activity of the catalyst was evaluated in the polymerization of ethylene. The kinetic behavior was also studied. It showed a high reservation of activity even when exposed to a high relative humidity for hours. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3944–3948, 2006
Effect of miscibility and forced compatibility on damping properties of CIIR/PAc blend
Authors: Su Huang Guang , Ru He Xiang , Rong Wu Jing , Ying Pan Qi , Zhen Jing , Hong Zhuo 
Published: August 2006

AbstractIn this study, a kind of novel damping materials was prepared based on the blend of chlorinated butyl rubber (CIIR) and polyacrylate (PAc) synthesized by different molar ratio of butyl methacrylate and ethyl acrylate. Research results from experiments and analyses by employing DMA, TEM, and FTIR show that whether at a cocured system or noncocured system, it can be achieved to shift a loss peak of CIIR towards a higher temperature region and to keep the damping value from markedlly decreasing, which broadens the effective damping function area of CIIR to the vicinity of ambient temperature. In the former system, the thermodynamical miscibility of CIIR and PAc, to some extent, is predominated by the molecular design of PAc, while in the latter system, covulcanized networks play a more significant role in improving compatibility and abating the peak split, though the suppression effect of thermal stress on the transition of CIIR Tll transition still can not be neglected. Furthermore, transition state derived from the cocuring CIIR and PAc cannot make the phase separation completely take place, and consequently results in the deformation of phase morphology of the cocured CIIR/PAc blend. It is the influence of thermodynamics miscibility and forced compatibility in different size that makes the suppression effect of foreign PAc on CIIR Tll transition be controllable. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3127–3133, 2006
Compatibilization of PP/EPDM blends by grafting acrylic acid to polypropylene and epoxidizing the diene in EPDM
Authors: Ao Y. H. , Sun S. L. , Tan Z. Y. , Zhou C. , Zhang H. X. 
Published: August 2006

AbstractIn this article, ethylene–propylene–diene‐rubber (EPDM) was epoxidized with an in situ formed performic acid to prepare epoxided EPDM (eEPDM). The eEPDM together with the introduction of PP‐g‐AA was used to compatibilize PP/EPDM blends in a Haake mixer. FTIR results showed that the EPDM had been epoxidized. The reaction between epoxy groups in the eEPDM and carboxylic acid groups in PP‐g‐AA had taken place, and PP‐g‐EPDM copolymers were formed in situ. Torque test results showed that the actual temperature and torque values for the compatibilized blends were higher than that of the uncompatibilized blends. Scanning electron microscopy (SEM) observation showed that the dispersed phase domain size of compatibilized blends and the uncompatibilized blends were 0.5 and 1.5 μm, respectively. The eEPDM together with the introduction of PP‐g‐AA could compatibilize PP/EPDM blends effectively. Notched Izod impact tests showed that the formation of PP‐g‐EPDM copolymer improved the impact strength and yielded a tougher PP blend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3949–3954, 2006
Developing protective textile materials as barriers to liquid penetration using melt‐electrospinning
Authors: Lee Seungsin , Kay Obendorf S. 
Published: August 2006

AbstractElectrospun polypropylene fiber webs and laminates were developed using melt‐electrospinning, to explore an alternative way of manufacturing protective clothing materials for agricultural workers. Electrospun polypropylene webs were fabricated in two levels of thickness. To examine the effect of lamination on the protection/thermal comfort properties, the webs were laminated on nonwoven fabric substrates. Barrier performance was evaluated for the electrospun webs and laminates, using two pesticide mixtures that represent a range of surface tension and viscosity. Effects of web thickness and lamination on air permeability and water vapor transmission were assessed as indications of thermal comfort performance. Penetration testing shows that electrospun polypropylene webs provide excellent barrier performance against the high surface tension challenge liquid, whereas the laminated fabrics of electrospun polypropylene webs exhibited performance of 90–100% for challenge liquids with varying surface tension. Air permeability of electrospun polypropylene webs decreased by ∼20% because of the lamination and web thickness, but was still higher than most of the materials currently in use for protective clothing. Water vapor transmission of electrospun polypropylene webs reduced by up to 12% from the lamination and web thickness as well, but was still in a range comparable to woven work clothing fabrics. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3430–3437, 2006
Dispersion copolymerization of acrylamide with acrylic acid in an aqueous solution of ammonium sulfate: Synthesis and characterization
Authors: Liu Xiaoguang , Chen Dongnian , Yue Yumei , Zhang Wende , Wang Pixin 
Published: August 2006

AbstractDispersion copolymerization of acrylamide with acrylic acid in an aqueous solution of ammonium sulfate using poly(2‐acrylamido‐2‐methylpropanesulfonic acid sodium) as the stabilizer and ammonium persulfate (APS) as the initiator was investigated. The influence of initiator concentration, stabilizer concentration, ammonium sulfate concentration, chain‐transfer agent concentration, and polymerization temperature on the copolymerization was discussed. The results showed that varying the ammonium sulfate concentration could affect the particle size and the intrinsic viscosity of the copolymer significantly. With increasing the stabilizer concentration, the particle size of the copolymer decreased first, and then increased, meanwhile the intrinsic viscosity of the copolymer decreased. The increase of initiator concentration, chain‐transfer agent concentration, and polymerization temperature resulted in the increase in the particle size. Polydisperse spherical particles were formed in the system, and the kinetics for the dispersion copolymerization were discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3685–3690, 2006
Rheological properties in blends of poly(aryl ether ether ketone) and liquid crystalline poly(aryl ether ketone)
Authors: Chen Jian , Liu Xincai , Yang Decai 
Published: August 2006

AbstractRheological properties of the blends of poly(aryl ether ether ketone) (PEEK) with liquid crystalline poly(aryl ether ketone) containing substituted 3‐trifluoromethylbenzene side group (F‐PAEK), prepared by solution precipitation, have been investigated by rheometer. Dynamic rheological behaviors of the blends under the oscillatory shear mode are strongly dependent on blend composition. For PEEK‐rich blends, the systems show flow curves similar to those of the pure PEEK, i.e., dynamic storage modulus G′ is larger than dynamic loss modulus G″, showing the feature of elastic fluid. For F‐PAEK‐rich systems, the rheological behavior of the blends has a resemblance to pure F‐PAEK, i.e., G″ is greater than G′, showing the characteristic of viscous fluid. When the PEEK content is in the range of 50–70%, the blends exhibit an unusual rheological behavior, which is the result of phase inversion between the two components. Moreover, as a whole, the complex viscosity values of the blends are between those of two pure polymers and decrease with increasing F‐PAEK content. However, at 50% weight fraction of PEEK, the viscosity‐composition curves exhibit a local maximum, which may be mainly attributed to the phase separation of two components at such a composition. The changes of G′ and G″ with composition show a trend similar to that of complex viscosity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4040–4044, 2006
Adjustable temperature sensor with double thermoresponsiveness based on the aggregation property of binary diblock copolymers
Authors: Wu Kai , Shi Linqi , Zhang Wangqing , An Yingli , Zhu Xiao‐Xia 
Published: August 2006

AbstractThis article presents a new and promising way to design a temperature sensor, which is based on the micellization or aggregation behavior of binary diblock copolymers of poly(ethylene glycol)‐b‐poly(N‐isopropylacrylamide) (PEG‐b‐PNIPAM) and poly(ethylene glycol)‐b‐poly(4‐vinylpyridine) (PEG‐b‐P(4‐VP)). The temperature sensor presents both a lower critical response temperature (LCRT) and an upper critical response temperature (UCRT), where the thermoreversible aggregating of PEG‐b‐P(4‐VP) and H2SO4 is used to control the LCRT, and the thermoreversible micellization of PEG‐b‐PNIPAM is used to control the UCRT. Furthermore, the LCRT can be altered by changing the H2SO4 concentration, and the UCRT can be adjusted by altering the PEG‐b‐PNIPAM concentration. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3144–3148, 2006
A new and simple way of preparing polycation‐grafted fibrous cellulose
Authors: Roche Philippe 
Published: August 2006

AbstractA new way of producing polycation‐grafted fibrous cellulose for its use as a retention aid in the papermaking process was conceived. It consists of adding, under intense stirring, to a cellulose fibers suspension at a basic pH a cationic polyacrylamide dissolved in water. As the cellulose fiber's surface is negatively charged because of its more or less acid groups, the cationic polymer adsorbs on it. The cationic‐grafted cellulose fibers are very similar to the cellulose fibers used in papermaking, since the polymer is (on a micrometer scale) homogeneously grafted on them as a film. It could so be used to increase the retention of the negatively charged fillers, fibers, and pigments during the process, without altering the properties of the resulting sheet of paper. The amount of polymeric grafts depends on the quantity of anionic groups on fiber's surface and varies monotonically with the grafting temperature and polyacrylamide's concentration in the blend. The grafted fibrous cellulose is well stable, even in drastic media and for lower Mw grafts, and the amount of grafted polymer also depends on the concentration and characteristics of fiber's suspension. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3149–3157, 2006
Thermal and dynamic mechanical characterization of polyurethane–urea–imide coatings
Authors: Mishra Aswini K. , Chattopadhyay D. K. , Sreedhar B. , Raju K. V. S. N. 
Published: August 2006

AbstractA series of NCO terminated polyurethane (PU)–imide copolymers were synthesized by a systematic three‐step process and were chain extended with different diol/diamine chain extenders. In the first step, isocyanate terminated PU prepolymers were prepared by reacting soft segments such as polyester (PE) polyols and polyether polyols such as polypropylene glycol (PPG‐1000) with hard segments like 2,4‐tolylene‐diisocyanate (TDI) or isophorone‐diisocyanate (IPDI) with NCO/OH ratio 2:1. In the second step, thermally stable heterocyclic imide ring was incorporated using isocyanate terminated PU prepolymers by reacting with pyromellitic dianhydride (PMDA) in a excess‐NCO:anhydride ratio of 1:0.5. The surplus NCO content after imidization was both moisture cured or partially reacted with chain extender and moisture cured. The films were characterized by thermogravimetric (TG), differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) instruments. The adhesion strength of these coatings on mild steel (MS), copper (Cu), and aluminum (Al) is dependent on the nature of the substrate. The TGA analysis show good thermal stability. The DMTA results show the microphase separation between the different hard and soft segments. Finally, a structure to property correlation was drawn based on the structure of the soft, hard, and chain extender and the observed properties are useful for understanding and design of intelligent coatings. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3158–3167, 2006
Study of piezo‐damping properties of CPE/ZKF/VGCF composites
Authors: Ding Xin Bo , Yan Xiong 
Published: August 2006

AbstractThe electrical and damping behaviors of chlorinated polyethylene (CPE)/2,2′‐methylene‐bis‐(4‐methyl‐6‐cyclohexylphenol) (ZKF)/vapor‐grown carbon fiber (VGCF) have been investigated. CPE/ZKF/VGCF systems exhibit typical percolation characteristics of filled conductive polymer composites. For CPE/ZKF/VGCF composites, dynamic mechanical analysis (DMA) shows that, at the glass transition temperature (Tg) of CPE/ZKF system, the values of loss factor increase with the increasing VGCF content. Within the temperature range of 60–75°C, the values of loss factor for CPE/ZKF/VGCF samples are higher than that of CPE/ZKF and present a peak at 16 vol% VGCF content. This implies that the piezo‐damping effect is directly related to the conductive network formation in the composites, and the piezo‐damping effect can be regulated by regulating the VGCF content. Therefore, the composite of CPE/ZKF/VGCF is a good damping material with a high and broad loss factor that can be regulated according to practical applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3181–3185, 2006
Model of liquid permeability in swollen composites of superabsorbent polymer and fiber
Authors: Buchholz Fredric L. 
Published: August 2006

AbstractThe liquid permeability of composites of fiber and superabsorbent polymer (SAP) is critical to the proper performance of absorbent hygiene products such as infant diapers. Previous work has focused on empirically improving performance of absorbent composites by modifying the components, but a systematic study of the parameters affecting permeability of these systems has not been published. A good model of permeability would aid our understanding of the complex phenomenon of liquid permeability of pads that change in volume and porosity during swelling. In the present work, a mathematical model of liquid permeability in both gel beds and composites of fiber and gel is developed. The model uses a Carman–Kozeny approach with added calculation of the porosity and specific surface area that result upon swelling of the SAP, as well as subsequent compression of the swollen composite. The model incorporates ten parameters that are necessary to determine the permeability of the system. The implications of the model for improving permeability in absorbent composites are explored. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4075–4084, 2006