bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymerization of halogenated anilines by plasma
Authors: Olayo M. G. , Enríquez M. A. , Cruz G. J. , Morales J. , Olayo R. 
Published: September 2006

AbstractThis work presents an experimental study about the electric conductivity in polyanilines synthesized by plasma obtained from halogenated anilines in which chlorine or iodine atoms are bonded in meta position to the aniline rings. The objective is to study the enhancement of the electric conductivity of these structures due to the addition of electronegative atoms to the polymeric chains. The results show that the halogenated anilines produce polymers with an electric conductivity up to eight orders of magnitude higher than those of the undoped polyanilines, reaching ∼10−4 S/cm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4682–4689, 2006
Influence of curing agent and compatibilizer on the physicomechanical properties of polypropylene/nitrile butadiene rubber blends investigated by positron annihilation lifetime technique
Authors: Soares B. G. , Almeida M. S. M. , Deepa Urs M. V. , Kumaraswamy G. N. , Ranganathaiah C. , Siddaramaiah  , Mauler R. 
Published: September 2006

AbstractA series of thermoplastic vulcanizates of polypropylene (PP)/nitrile butadiene rubber (NBR) (50/50) have been prepared by melt‐mixing method, using phenolic resin/SnCl2 as the curing system and maleic anhydride‐functionalized PP (PP‐g‐MA) and carboxylated NBR (NBRE‐RCOOH) as the compatibilizing system. Triethylenetetramine was also employed to promote the reaction between the functionalized polymers. The effects of curing agent and compatibilizer on the mechanical and morphological properties have been studied. A novel technique based on positron annihilation lifetime spectroscopy has been used to measure the free volume parameters of these systems. The positron results showed minimum free volume size and free volume fraction at 5.0% of the curing agent suggesting some crosslinking in the rubber phase. The reduction in free volume holes at 2.5% of the compatibilizer is interpreted as improvement in the interfacial adhesion between the components of the blend. The observed variation of free volume fraction is opposite to the tensile strength and exhibits the correlation that, lesser the free volume more is the tensile strength at 2.5% of the compatibilizer in the blend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4672–4681, 2006
Microwave‐assisted preparation of temperature sensitive poly(N‐isopropylacrylamide) hydrogels in poly(ethylene oxide)‐600
Authors: Shi Shaohua , Liu Lijian 
Published: September 2006

AbstractIn this article, a series of poly(N‐isopropylacrylamide) (PNIPAM)‐based hydrogels were prepared under microwave irradiation using poly(ethylene oxide)‐600 (PEO‐600) as reaction medium and microwave‐absorbing agent as well as pore‐forming agent. All of the temperature measurements, gel fractions, and FTIR analyses proved that the PNIPAM hydrogels were successfully synthesized. Within 1 min, the PNIPAM hydrogel with a 98% yield was obtained under microwave irradiation. The PNIPAM hydrogels thus prepared exhibited controllable properties such as pore size, equilibrium swelling ratios, and swelling/deswelling rates when changing the feed weight ratios of monomer (N‐isopropylacrylamide, NIPAM) to PEO‐600. These properties are well adapted to the different requirements for their potential application in many fields such as biomedicine. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4177–4184, 2006
Effect of immobilized neutral protease on the preparation and physicochemical properties of low molecular weight chitosan and chito‐oligomers
Authors: Li Jin , Du Yu Min , Liang Hong Bo , Yao Ping Jia , Wei Yuan An 
Published: September 2006

AbstractNeutral protease was immobilized on glutaraldehyde‐pretreated N‐succinyl chitosan hydrogel beads and the biocatalyst obtained was used for the preparation of low molecular weight chitosan and chito‐oligomers with molecular weight of 1.9–23.5 kDa from commercial chitosan. Factors affecting the chitinolytic hydrolysis were described. The degradation was monitored by gel permeation chromatography. The structure of degraded chitosan was characterized by Fourier transform infrared, X‐ray diffraction and liquid chromatography‐mass spectrometry. Immobilized neutral protease showed optimal depolymerization at pH 5.7 and 50°C. The degree of deacetylation of the hydrolysates did not change compared to that of the initial chitosan. The decrease of molecular weight led to transformation of crystal structure but the chemical structures of residues were not modified. The degree of polymerization of chito‐oligomers was mainly from 3 to 8. The method allows cyclic procedures of immobilized enzyme and N‐succinyl chitosan support utilization, and is suitable for a large‐scale production of the low molecular weight chitosan and chito‐oligomers free of protein admixtures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4185–4193, 2006
Interfacial adhesion through maleic anhydride grafting of EPDM in PP/EPDM blend
Authors: Purnima D. , Maiti S. N. , Gupta A. K. 
Published: September 2006

AbstractThis paper presents a study of interface modification effect through the use of maleic anhydride (MAH) grafting on one of the component polymers of the binary blend. The system used is binary blend of polypropylene (PP) and the elastomer EPDM (copolymer of ethylene–propylene–diene monomer). Two sets of the blend (i) PP/EPDM binary blend and (ii) PP/EPDM‐g‐MAH binary blend at constant degree of grafting (i.e., EPDM : MAH ratio) and at varying blending ratios were studied and compared for the properties and structure development. Results are discussed to illustrate the effect of interfacial modification due to presence of MAH by comparing the data of mechanical properties and crystallization behavior for the two sets of the binary blend at identical blending ratios, as well as to study the trends of variation of properties with blending ratio for each individual set of the blend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5528–5532, 2006
Effect of the interface with solid on the interfacial region in the blends of linear polymers formed in situ
Authors: Lipatov Yu. S. , Kosyanchuk L. F. , Yarovaya N. V. 
Published: September 2006

AbstractBlends of polyurethane and poly (methyl methacrylate) of various compositions were synthesized in situ in presence of various amounts of nanoparticles (fumed silica). From thermo‐ physical measurements it was found that the reaction is accompanied by the phase separation and evolution of two phases. The temperature transitions in the systems and their positions depend on the blend composition and on the filler amount. Using scanning differential calorimetry, the fraction of an intermediate region between two main phases has been estimated from the changing of heat capacity increments. It was observed that in filled polymer blends in the temperature region between two main relaxation transitions, there appears the third transition. This transition is supposed to be the result of the formation of adsorption layer at the interface with solid. The appearance of such an intermediate regions increases essentially the total fraction of an interfacial region in the system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4646–4651, 2006
Effects of polydimethylsiloxane concentration on properties of polyurethane/polydimethylsiloxane hybrid dispersions
Authors: Fei Guiqiang , Shen Yiding , Wang Haihua , Shen Yue 
Published: September 2006

AbstractA series of waterborne polyurethane (WPU) derived from isophorone isocyanate and poly(tetramethylene glycol) were modified by hydroxyl‐terminated polydimethylsiloxane (HPMS). The solutions were then cast into films named as PUHS. Rheological behavior of the emulsions were studied using Rheometer and morphology was studied with transmission electron microscope. Meanwhile, the casting films were prepared from the WPU/HPMS hybrid dispersions, and their glass transition behavior, miscibility, water resistance, and medium resistance were studied with differential scanning calorimeter (DSC), wide‐angle X‐ray diffraction (WAXD), and so on. The results revealed that the emulsions' particle size decreases with increasing HPMS content and the particles are more easily affixed to each other when the HPMS content is more than 15%, and emulsions are endowed with pseudoplasticity and thixotropy. WAXD and DSC figures manifested that the casting films all exhibited a certain degree of miscibility. The degrees of crystallinity (xc) decreased with increasing HPMS content, and the PUHS films were almost amorphous. It is noticed that water and medium absorption increased in the HPMS/PU compared to pure PU, which demonstrate that the membrane surfaces have excellent water and chemical medium repellency. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5538–5544, 2006
Synthesis and characterization of new flame‐retardant poly(amide‐imide)s containing phosphine oxide and hydantoin moieties in the main chain
Authors: Faghihi Khalil 
Published: September 2006

AbstractSix new flame‐retardant poly(amide‐imide)s (PAIs) 9a–f with high inherent viscosities containing phosphine oxide and hydantoin moieties in main chain were synthesized from the polycondensation reaction of N,N′‐(3,3′‐diphenylphenylphosphine oxide) bistrimellitimide diacid chloride 7 with six hydantoin derivatives 8a–f by two different methods such as solution and microwave assisted polycondensation. Results showed that the microwave assisted polycondensation, by using a domestic microwave oven, proceeded rapidly, compared with solution polycondensation, and was completed in about 7–9 min. All of the obtained polymers were fully characterized by means of elemental analysis, viscosity measurements, solubility test, and FTIR spectroscopy. Thermal properties and flame retardant behavior of the PAIs 9a–f were investigated using thermal gravimetric analysis (TGA and DTG) and limited Oxygen index (LOI). Data obtained by thermal analysis (TGA and DTG) revealed that these polymers showed good thermal stability. Furthermore, high char yields in TGA and good LOI values indicated that these polymers are capable of exhibiting good flame retardant properties. These polymers can be potentially utilized in flame retardant thermoplastic materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5062–5071, 2006
Synthesis and characterization of dextran hydrogels prepared with chlor‐ and nitrogen‐containing crosslinkers
Authors: İmren Dilek , Gümüşderelioğlu Menemşe , Güner Ali 
Published: September 2006

AbstractIn this study, we have synthesized dextran hydrogels by the crosslinking reactions of dextran with some selective Cl‐, and N‐containing functional monomers, such as epichlorohydrin (ECH), N,N′‐methylenebisacrylamide (MBAm), and glutaraldehyde (GA). Crosslinking reactions were carried out in the basic aqueous solutions (2.8NNaOH) at 25–50°C. The optimum conditions for effective crosslinking, i.e., temperature, crosslinking time, and amount of crosslinker, were determined for each system. The hydrogel discs of 3 mm diameter and 1.5 mm thickness were subjected to a number of Tris‐buffer solutions of desired pH (2.0–9.0) at 37°C. Swelling kinetics of the hydrogels were evaluated with second–order swelling model. The pH‐dependent swelling of hydrogels was strongly influenced by the functional group of crosslinker and crosslinker content. While the hydrogels prepared with ECH and MBAm shows higher swelling ability at basic medium than that of acidic medium, GA‐containing hydrogels exhibited just the opposite behavior. Mesh sizes (ξ) and average molecular weights between crosslinks (Mc) were estimated from swelling data using the Flory‐Rehner theory. Characterization studies were completed by Fourier transform infrared spectroscopy and thermal gravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4213–4221, 2006
Aluminosilicate‐filled composites of PVA–PVP—An improved biodegradable polymeric material
Authors: Saha Nabanita , Ali S. K. Akbar , Kar Sritama , Saha Petr , Banthia Ajit K. 
Published: September 2006

AbstractPoly(viny alcohol)–poly(vinyl pyrrolidone) biodegradable polymer blend was modified with aluminosilicate. Sample films containing 5, 10, 15, and 20 wt % filler were prepared by conventional solvent casting technique using glass plates as casting surfaces. The newly developed biodegradable composites are bright red, with magnetic properties due to the presence of iron compounds. Physical, chemical, and biodegradable properties of the films were studied with the conclusion that the presence of aluminosilicate affects the properties of the matrix and enhances biodegradability of the polymer composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4963–4970, 2006
Rheological behavior of polyester blend and mechanical properties of the polypropylene–polyester blend fibers
Authors: Marcinčin Anton , Körmendy Eva , Hricová Marcela , Rusnák Andrej , Aneja Arun Pal 
Published: September 2006

AbstractThe article deals with method of preparation, rheological properties, phase structure, and morphology of binary blend of poly(ethylene terephthalate) (PET)/poly(butylene terephthalate) (PBT) and ternary blends of polypropylene (PP)/(PET/PBT). The ternary blend of PET/PBT (PES) containing 30 wt % of PP is used as a final polymer additive (FPA) for blending with PP and subsequent spinning. In addition commercial montane (polyester) wax Licowax E (LiE) was used as a compatibilizer for spinning process enhancement. The PP/PES blend fibers containing 8 wt % of polyester as dispersed phase were prepared in a two‐step procedure: preparation of FPA using laboratory twin‐screw extruder and spinning of the PP/PES blend fibers after blending PP and FPA, using a laboratory spinning equipment. DSC analysis was used for investigation of the phase structure of the PES components and selected blends. Finally, the mechanical properties of the blend fibers were analyzed. It has been found that viscosity of the PET/PBT blends is strongly influenced by the presence of the major component. In addition, the major component suppresses crystallinity of the minor component phase up to a concentration of 30 wt %. PBT as major component in dispersed PES phase increases viscosity of the PET/PBT blend melts and increases the tensile strength of the PP/PES blend fibers. The impact of the compatibilizer on the uniformity of phase dispersion of PP/PES blend fibers was demonstrated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4222–4227, 2006
Study of viscosity abnormality of PS/toluene solution in extremely dilute concentration regime
Authors: Du Deng‐Xue , Zuo Ju , An Ying‐Li , Zhou Lei , Liu Yun 
Published: September 2006

AbstractThe concentration dependence of the reduced viscosity ηsp/c and the translational diffusion coefficient D as well as the radius of gyration Rg of polystyrene in toluene were studied by viscometry and laser light scattering (LLS), respectively. The influence of the experimental error on the determination of the ηsp/c was investigated and a quantitative relation was given out. Viscometric experiment found that the ηsp/c–c curve is clearly divided into two parts by dynamic contact concentration cs. When c > cs, it shows normal linearity as predicted by Huggins equation. But when c < cs, i.e., in the extremely dilute regime, the ηsp/c–c curve is no longer linear and levels off considering the experimental uncertainty. This new finding was confirmed by the following LLS experiment, which indicates that the size of the polymer chains no longer varies with concentration when c < cs. As a result, we, for the first time, using the method of combination of viscometry and LLS, prove an important conclusion that in the extremely dilute concentration regime, the reduced viscosity of polymer solution, at least for PS/toluene, conforming to the Einstein viscosity equation is just the intrinsic viscosity and independent of the concentration. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4440–4446, 2006
Copolymers of acrylic acid with 2‐acryloyloxyethyl 2,4‐dichlorophenoxyacetate: Synthesis and herbicide release
Authors: Fernández‐García Marta , Sánchez‐Chaves Manuel 
Published: September 2006

AbstractFree‐radical copolymerization of acrylic acid with 2‐acryloyloxyethyl 2,4‐dichlorophenoxyacetate using 1.0 mol/L 1,4‐dioxane solution and 1.5 × 10−2 mol/L of 2,2′ azobisisobutyronitrile as initiator has been carried out at 50°C. In addition to low conversion solution experiments performed to estimate the monomer reactivity ratios, three different copolymerizations over the whole range of conversions have been made. Theoretical values of cumulative copolymer composition, determined by the Mayo‐Lewis terminal model, have been correlated with those experimentally obtained. Finally, the herbicide release in three different aqueous pH buffer solutions has been evaluated in heterogeneous phase. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4238–4244, 2006
Effects of multiple weak interactions on the binding of phenolic compounds by polymeric adsorbents
Authors: Cheng Shaoling , Tang Haiyan , Yan Husheng 
Published: September 2006

AbstractTo investigate the effects of multiple weak interactions on the binding of phenolic compounds by polymeric adsorbents, macroporous polystyrene (PS) resin and PS‐based adsorbents with different hydrogen‐bond acceptor atoms (PSCH2(OCH2CH2)nOCH3, n = 0, 1, 2, and 3, denoted as PS‐EG0, PS‐EG1, PS‐EG2, and PS‐EG3) were prepared. The phenol adsorption strength order on these adsorbents was PS/PS‐EG0 < PS‐EG1 < PS‐EG2 < PS‐EG3, indicating that the adsorption on PS and PS‐EG0 was driven by hydrophobic and π–π interactions, and the adsorption on PS‐EG1, PS‐EG2, and PS‐EG3 was driven by a hydrogen bond in addition to hydrophobic and π–π interactions. PS‐EG2 may adsorb a second phenol molecule on each binding site and PS‐EG3 may adsorb second and third ones. The adsorption strength of resorcinol increased in the order of PS, PS‐EG1, and PS‐EG2, indicating that the adsorption was driven by 0, 1, and 2 hydrogen bonds in addition to hydrophobic and π–π interactions. Similarly, the adsorption of phloroglucinol on PS, PS‐EG1, PS‐EG2, and PS‐EG3 was driven by 0, 1, 2, and 3 hydrogen bonds in addition to hydrophobic and π–π interactions because the adsorption strength increased in this order. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4652–4658, 2006
Control of coefficient of thermal expansion in elastomers using boron nitride
Authors: Iyer Subramanian , Detwiler Andrew , Patel Sanjay , Schiraldi David A. 
Published: September 2006

AbstractThe thermal expansion properties of three commercial elastomers; Pebax®, Estane® and Hytrel® modified with 2.5–10 wt % boron nitride were investigated. The glass transition temperatures of the filled materials were relatively unaffected; however boron nitride did effectively reinforce all the three elastomers as seen by dynamic mechanical analysis and tensile tests. The coefficients of thermal expansion of the composite materials do not obey the rule of mixtures and show a large decrease without the loss of ductility typically associated with filled elastomers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5153–5161, 2006
Effects of the molecular structure of impact modifier and compatibilizer on the toughening of PBT/SBS/PS‐GMA blends
Authors: Canto L. B. , Hage E. , Pessan L. A. 
Published: September 2006

AbstractThis work aims at studying the toughening process of poly(butylene terephthalate) (PBT) through its blends with styrene‐butadiene‐styrene block copolymers (SBS), in the presence of poly(styrene‐ran‐glicydil methacrylate) (PS‐GMA) as reactive compatibilizer. High values of impact strength were attained for PBT/SBS blends without the compatibilizer; however, this improvement is achieved for blends with SBS having similar viscosity compared to PBT, at high SBS content (40 wt %) and for blends prepared under specific processing conditions. The efficiency of the in situ compatibilization of PBT/SBS blends by PS‐GMA was found to be strongly dependent on the SBS and PS‐GMA molecular characteristics. Better compatibilizing results were observed through fine phase morphologies and lower ductile to brittle transition temperatures (DBTT) as the interfacial interaction and stability of the in situ formed compatibilizer are maximized, that is, when the miscibility between SBS and PS‐GMA and reaction degree between PBT and PS‐GMA are maximized. For the PBT/SBS/PS‐GMA blends under study, this was found when it is used the SBS with higher polystyrene content (38 wt %) and with longer PS blocks (Mw = 20,000 g mol−1) and also the PS‐GMA with moderate GMA contents (4 wt %) and with molecular weight similar to the critical one for PS entanglements (Mc = 35,000 g mol−1). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5795–5807, 2006
Production and characterization of natural fiber‐reinforced thermoplastic composites using wheat straw modified with the fungus Pleurotus ostreatus
Authors: Schirp Anke , Loge Frank , Aust Steven , Swaner Paul , Turner Glenn , Wolcott Michael 
Published: September 2006

AbstractWheat straw is an abundantly available and potentially valuable biomass that is currently under‐exploited. In this study, the feasibility of using wheat straw as a filler in high‐density polyethylene (HDPE)‐based composites was explored. Straw was treated with the white‐rot fungus Pleurotus ostreatus with the aim of improving adhesion between straw and plastic, and thereby the mechanical properties of the composite. Results indicate that the use of sterilized straw is necessary to inhibit the growth of indigenous organisms that preclude, likely through competition, removal of lignin, and hence, improved bonding between straw and plastic. Light and transmission electron microscopy revealed cell wall modification in sterilized, inoculated straw. Reduced thermal stability of treated straw did not negatively affect the production of injection‐molded straw–plastic composites (SPC). Comparable interfacial adhesion, based on activation energies obtained in dynamic mechanical analysis, was observed in untreated and treated straw‐ and pine‐based thermoplastic composites. The results of this study indicate that wheat straw represents a promising alternative to wood fillers in the production of thermoplastic composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5191–5201, 2006
Free‐radical copolymerization kinetics of acrylonitrile and methyl acrylate in [BMIM]BF4
Authors: Li Da , Zhang Yumei , Wang Huaping , Tang Jianzhong , Wang Biao 
Published: September 2006

AbstractThe copolymerization of acrylonitrile (AN) and methyl acrylate (MA) was carried out in ionic liquid [BMIM]BF4 in the presence of azobisisobutyronitrile (AIBN) as an initiator to investigate the polymerization kinetic, including the copolymerization rate, reactivity ratios, and activation energy. The copolymerization rate equation was established according to the effect of initiator and monomer concentrations on the conversion. The copolymerization rate Rp can be noted as $R_p = {\rm KC}_{\rm AIBN} {^{0.74}} C_{\rm MA} {^{0.61}} C_{\rm AN} {^{0.44}}$, when the copolymerization was in the steady state. The apparent activation energy is 87.94 kJ/mol, while the value of that in the conventional organic solvent (DMF) is ∼ 81 kJ/mol. The reactivity ratios of the investigate system are rAN = 0.36 and rMA = 0.68. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4254–4257, 2006