bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects on the structure and properties of membranes formed by blending polydimethylsiloxane polyurethane into different soft‐segment waterborne polyurethanes
Authors: Yen Meng‐Shung , Tsai Ping‐Yuan
Published: July 2006

Polydimethylsiloxane polyurethane (PDMS‐PU), which was synthesized from PDMS as the soft segment, was blended into a variety of ester‐ or ether‐based soft‐segment waterborne polyurethanes with different concentrations to investigate the crystallization, thermal, and physical properties of the membrane formations. According to X‐ray analysis, the ether‐based PUs, synthesized from soft segments of poly(propylene glycol) (PPG1000) or poly(ethylene glycol) (PEG2000), were found to have maximum crystallinity at a 5% blending ratio of PDMS‐PU, but the ester‐based PU, synthesized from soft segments of polycaprolactone (PCL1250), had decreased crystallinity at a 5% blending ratio. Differential scanning calorimetric analysis revealed that the Tg,s values of PUs were highest when the blending ratio of PDMS‐PU was 5%–10%, except for PU from PCL1250. Moreover, ether‐based PUs showed maximum Tm,h values, but the Tm,h of the ester‐based PU was greatly reduced when PU with PCL1250 was blended with PDMS‐PU. In addition, the PU from PEG2000 had the highest melting entropy. Mechanical property analysis showed that the stress of ether‐based PUs would be increased when PUs were blended with a small amount of PDMS‐PU and that the stress of PU from poly(tetramethylene glycol) (PTMG1000) increased to its greatest value (20–30 MPa). On the other hand, the ester‐based PU, from PCL1250 blended with PDMS‐PU, would have reduced stress. On the whole, the stress and strain of PU from PEG1000 had excellent balance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 210–221, 2006
Distribution of carbon black in natural rubber/acrylic rubber blends
Authors: Wootthikanokkhan J. , Rattanathamwat N.
Published: July 2006

Distributions of carbon black in 30/70% (w/w) natural rubber (NR)/acrylic rubber (ACM) blends were investigated as a function of the carbon black content and type using a dynamic mechanical thermal analysis (DMTA) technique. Two different types of carbon black (N220 and N330) were used, and 10–50 phr carbon black was compounded to the rubber blends. From the DMTA thermograms of various blends, the weight fractions of carbon black in the NR and ACM phases were calculated. Carbon black was unevenly distributed in the rubber blend. It preferred to migrate into the NR phase, regardless of the amount of carbon black that was used. By increasing the carbon black content, the weight fraction of carbon black in the NR phase decreased whereas that in the ACM phase increased. A change in the type of carbon black from N220 to N330 significantly decreased the weight fraction of carbon black in the NR phase, but it was not sufficiently strong to affect the tensile properties and hardness of the rubber blend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:248–256, 2006
Interaction between polyacrylonitrile and alkalis
Authors: Hou Chen , Qun Wang , Qu Rongjun , Wang Chengguo
Published: July 2006

Interactions between highly isotactic acrylonitrile homopolymers and alkalis in dimethyl sulfoxide solvent were examined. Coloration occurred as soon as polyacrylonitrile was added to a dimethyl sulfoxide/alkali mixture. The effects of alkali on highly isotactic polyacrylonitrile were greater than those on ordinary polyacrylonitrile. The intrinsic viscosity of polyacrylonitrile decreased quickly with the addition of sodium ethoxide and sodium hydroxide, and the effect of sodium ethoxide was more prominent than that of sodium hydroxide. As the concentration of sodium ethoxide and sodium hydroxide went beyond 0.01 mol/L, the intrinsic viscosity showed a trend of increasing. Within the first half‐hour, there was a great drop in the intrinsic viscosity of highly isotactic polyacrylonitrile, and then the intrinsic viscosity appeared to increase. The intrinsic viscosity of highly isotactic polyacrylonitrile increased continuously with the addition of diethylamine along with time. The effects of alkalis on the tacticity of the polymers followed the order of the alkali strength. Diethylamine was more effective for moderating the stabilization exotherm of polyacrylonitrile than sodium ethoxide and sodium hydroxide. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 272–275, 2006
Photodegradation of poly(vinyl alcohol) under UV and pulsed‐laser irradiation in aqueous solution
Authors: Vijayalakshmi S. P. , Madras Giridhar
Published: July 2006

The photodegradation of poly(vinyl alcohol) (PVA) in aqueous solution was investigated under UV exposure and pulsed‐laser irradiation. The degradation under UV exposure was studied at different pH values and with the addition of potassium chloride and potassium dichromate. The pulsed‐laser degradation of PVA was investigated with a Nd : YAG laser, operating at a wavelength of 266 nm with about 6‐ns pulses. The pulsed‐laser degradation was studied at different polymer concentrations and light intensities. Samples were analyzed by gel permeation chromatography. The degradation rate coefficients were determined by the application of a continuous distribution model. The photodegradation rates under UV exposure were highest at extremes of pH and were greatly enhanced by the addition of potassium chloride and potassium dichromate. The pulsed‐laser degradation of the polymer decreased with increasing polymer concentration, although a threshold light intensity was required to initiate the degradation process. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 958–966, 2006
Ultraviolet grafting of styrene and maleic anhydride on polyethylene‐terephthalate film
Authors: Zhou Yanfei , Bai Yongping , Wei Jiangong
Published: July 2006

UV‐induced graft copolymerization with mixed monomers such as styrene (St) and maleic anhydride (MAH) onto the surface of polyethylene‐terephthalate (PET) films was carried out. The chemical properties and the morphology of the surface of grafted films were investigated via attenuated total reflection (ATR), scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. ATR images revealed that MAH was succeeded in being grafted. On the other hand, SEM and AFM analysis showed that many granules, which may be grafted St and MAH chains, formed after being treated for 40 s by UV light. The water contact angle of grafted film is about 43°,which reduced sharply compared with pristine film. UV spectra of CTC, which was formed by St and MAH, provided the argument about the mechanism of formation of grafted chains. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 285–288, 2006
Enhancing thermal conductivity and physical properties of phenol‐formaldehyde resin by adding VGCF during pyrolysis
Authors: Ko Tse‐Hao , Hu Hsien‐Lin , Kuo Wen‐Shyong , Wang Su‐How
Published: July 2006

After vapor‐grown carbon‐fibers (VGCF) were added to resol‐type phenolic resin, their influence on microstructure, thermal conductivity, flexural strength, and physical properties of the resin was characterized in this work. Resin with content 0–10 wt % VGCF was heat‐treated at 230–2500°C. As a result, it was observed that adding VGCF into resin during pyrolysis not only reduced weight loss but also limited shrinkage of resin. Moreover, adding VGCF to resin promoted the degree of arranging carbon basal planes and chemical densification of the structure of final heat‐treated resins. At 2500°C, the graphitized resin with 10 wt % VGCF enhanced flexural strength and thermal conductivity over 300%, while decreasing weight loss around 20% versus graphitized phenol‐formaldehyde resin developed from the original resin. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1531–1538, 2006
Molecular structure and ion exchange of amidoximated cellulosic materials
Authors: Nada A. M. A. , El‐Wakil Nahla A.
Published: July 2006

Modification of lignocellulosic materials, e.g., cotton stalks, bagasse, and rice straw, by incorporation of amidoxime group for ion exchange is investigated. The uptake of metal ions Cu, Cr, Ni, and Fe by these modified lignocellulosic materials is measured. Amidoximated bagasse has higher efficiency toward metal ions uptake than amidoximated cotton and rice straw. The effect of different variables, e.g., metal ion concentration, temperature of metal ion solution, and time of steeping, on the efficiency of the amidoximated (bagasse raw material, unbleached bagasse, and bleached bagasse) ion exchangers toward metal ions uptake is tested. The molecular structure of the prepared amidoxime from bagasse and its pulps is studied by using infrared spectroscopy. New bands appeared at 1661 and 916 cm−1 in the spectra of amidoximated bagasse and its pulps ion exchangers due to the formation of CN and NOH groups. The thermal properties of these ion exchangers is also studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 303–311, 2006
Variation of inhibited oxidation parameters in the range of phase transition
Authors: Kalinina I. G. , Gumargalieva K. Z. , Shlyapnikov Yu. A.
Published: July 2006

Parameters of inhibited oxidation of isotactic propylene containing antioxidant 2,2′‐methylene‐bis(4‐methyl‐6‐tert‐butylphenol) has been studied in the temperature range 140–210°C. Unlike polyethylene, the dependencies of inhibited oxidation parameters: of critical antioxidant concentration and of rate constant of antioxidant consumption change with temperature do not obey Arrhenius law both below and above the melting temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 312–314, 2006
Technological evaluation of reactive cyclodextrin in cotton printing with reactive and natural dyes
Authors: Hebeish A. A. , Ragheb A. A. , Nassar S. H. , Allam E. E. , El Thalouth J. I. Abd
Published: July 2006

The chemical modification of cotton fabric with reactive cyclodextrin (R‐CD) at different concentrations was carried out to enhance the printability of cotton fabric. The extent of the modification reaction was expressed as %N. Reactive and natural dyes were used to print cotton fabric before and after modification. Printing pastes were applied immediately after preparation or after 24 h of storage. Printing fixation was performed through either steaming or thermal treatment. The effect of the incorporation of R‐CD in the printing paste of unmodified cotton was also studied. The results reveal that the extent of the modification reaction increased with increasing R‐CD concentration and so did the color strength (K/S) of the printed sample regardless of the dye used. The results also revealed that K/S of the R‐CD modified cottons were higher than that of the corresponding unmodified samples regardless of the method of fixation or the time elapsed before printing. On the other hand, the incorporation of R‐CD in the printing pastes of reactive dyes, namely, Cibacron Brown 6R‐P or Remazol Brilliant Red GG, had adverse effects, most probability due to the (a) increasing viscosity of the paste and/or (b) interaction of the reactive dye with R‐CD hydroxyls. The opposite held true when a natural dye was used. Further, the incorporation of R‐CD in the printing pastes had no effect on the rheological type of the pastes or the on overall fastness properties of the prints. Nevertheless, such an incorporation of R‐CD was accompanied by a remarkable increase in the magnitude of the apparent viscosity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 338–347, 2006
Studies on synthesis, characterization, and metal adsorption of mimosa and valonia tannin resins
Authors: Özacar Mahmut , Soykan Cengiz , Şengi̇l İ. Ayhan
Published: July 2006

A few thermosetting wood adhesive tannin resin system from formaldehyde reaction with both condensed and hydrolysable tannin has been developed. Polymerization of formaldehyde with mimosa tannin and valonia tannin was carried out at optimal conditions obtained from literature to establish the adhesive resin formulation. Formed reaction products were characterized by FTIR spectroscopy. The possible adsorption mechanisms for the adsorption of various metal ions onto tannin‐formaldehyde resins were proposed. Also, thermal analysis were studied and discussed by differential scanning calorimetry and thermogravimetry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 786–797, 2006
PH‐dependent swelling behavior and network parametes of ionic poly(N‐t‐butylacrylamide‐co‐acrylamide) hydrogels
Authors: Turan Eylem , Demirel Gökhan , Zengin Meltem , Şimsek Dilek , Çaykara Tuncer
Published: July 2006

Ionic poly(N‐t‐butylacrylamide‐co‐acrylamide) [P(TBA‐co‐AAm)] hydrogels were synthesized by the free‐radical crosslinking copolymerization of N‐t‐butylacrylamide and acrylamide monomers in fixed amounts and the maleic acid (MA) comonomer in methanol in different amounts with N,N‐methylene bis(acrylamide) as the crosslinker, ammonium persulfate as the initiator, and N,N,N′,N′‐tetramethylenediamine as the activator. The swelling behavior of these hydrogels was analyzed in buffer solutions at various pHs. The polymer–solvent interaction parameter (χ) and the average molecular weight between crosslinks of the ionic P(TBA‐co‐AAm) hydrogels were calculated from swelling studies in buffer solutions at various pHs and were related to the MA content. The results indicated that the swelling behavior of the ionic P(TBA‐co‐AAm) hydrogels at different pHs agreed with the modified Flory–Rehner equation based on the affine network model and the ideal Donnan theory. The enthalpy (ΔH) and entropy (ΔS) changes appearing in the χ parameter for the hydrogels were also determined with the modified Flory–Rehner equation. The negative values for ΔH and ΔS indicated that the hydrogels had a negative temperature‐sensitive property in water, that is, swelling at a lower temperature and shrinking at a higher temperature. The experimental swelling data of the hydrogels at different temperatures agreed with the modified Flory–Rehner approach based on the affine network model, which ensured that the sensitive dependence of the χ parameter on both the temperature and polymer concentration was taken into account. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1624–1630, 2006
Effects of spinning and drawing conditions on the crimp contraction of side‐by‐side poly(trimethylene terephthalate) bicomponent fibers
Authors: Oh Tae Hwan
Published: July 2006

The crimp properties in the melt‐spinning and drawing processes of side‐by‐side bicomponent fibers with poly(trimethylene terephthalate)s (PTTs) of different viscosities were studied. Two PTTs of different intrinsic viscosities (1.02 and 0.92) were selected to make latent crimp yarn. The spinning and drawing conditions were changed to investigate the relation between the process conditions and crimp contraction. An orthogonal array was used to rule out the weak variables. The draw ratio, heat‐set temperature, and portion of high‐viscosity PTT were selected as variables having an effect on the crimp contraction. An analysis of the effects of the spinning and drawing conditions on the crimp contraction showed that the draw ratio was the most critical variable. Increasing the draw ratio caused a difference in the shrinkage between the two parts of PTT and caused the self‐crimping of the bicomponent fibers. Although changing the heat‐set temperature and the portion of high‐viscosity PTT did not produce a dimensional change, the crimp contraction varied with those variables. As the heat‐set temperature and the high‐viscosity portion increased, the crimp contraction increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1322–1327, 2006
Effect of the anionic‐group/cationic‐group ratio on the swelling behavior and controlled release of agrochemicals of the amphoteric, superabsorbent polymer poly(acrylic acid‐co‐diallyldimethylammonium chloride)
Authors: Xu Shimei , Wu Ronglan , Huang Xiaojuan , Cao Liqin , Wang Jide
Published: July 2006

A series of amphoteric, superabsorbent polymers [poly(acrylic acid‐co‐diallyldimethylammonium chloride)] with different molar ratios of anionic groups to cationic groups were prepared by solution polymerization to investigate their swelling behaviors and the controlled release of agrochemicals. Various factors, including the solution pH, the concentrations of different salt solutions, and the temperature, were studied. The dynamic parameters of hydrogels at different temperatures suggested that diffusion was Fickian at lower temperatures, whereas non‐Fickian diffusion prevailed at higher temperatures. A copolymer hydrogel with a low anionic‐group/cationic‐group ratio showed a higher swelling capacity in water and higher salt tolerance. Also, the anionic‐group/cationic‐group ratio was not the dominant factor in determining the water retention. A poly(acrylic acid‐co‐diallyldimethylammonium chloride) hydrogel could control the release of agrochemicals effectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 986–991, 2006
Structure and properties of polypropylene/low‐density polyethylene blends grafted with itaconic acid in the course of reactive extrusion
Authors: Krivoguz Y. M. , Pesetskii S. S. , Jurkowski B. , Tomczyk T.
Published: July 2006

This study was concerned with the structural features and mechanical properties of polypropylene (PP)/low‐density polyethylene (LDPE) blends, which after compounding were modified by the free‐radical grafting of itaconic acid (IA) to produce [PP/LDPE]‐g‐IA in the course of reactive extrusion. To analyze the structural features of the [PP/LDPE]‐g‐IA systems, differential scanning calorimetry and relaxation spectrometry techniques were used. The data were indicative of the incompatibility of PP and LDPE in the [PP/LDPE]‐g‐IA systems on the level of crystalline phases; however, favorable interactions were observed within the amorphous phases of the polymers. Because of these interactions, the crystallization temperature of PP increased by 5–11°C, and that of LDPE increased by 1.3–2.7°C. The rapprochement of their glass‐transition temperatures was observed. The single β‐relaxation peak for the [PP/LDPE]‐g‐IA systems showed that compatibility on the level of structural units was responsible for β relaxation in the homopolymers used. Variations in the ratios of the polymers in the [PP/LDPE]‐g‐IA systems led to both nonadditive and complex changes in the viscoelastic properties as well as mechanical characteristics for the composites. Additions of up to 5 wt % PP strengthened the [PP/LDPE]‐g‐IA blended systems between the glass‐transition temperatures of LDPE and PP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1746–1754, 2006
Surface functionalization of Si3N4 nanoparticles by graft polymerization of glycidyl methacrylate and styrene
Authors: Luo Ying , Rong Min Zhi , Zhang Ming Qiu , Friedrich Klaus
Published: July 2006

To improve dispersibility and interfacial interaction of nano‐Si3N4 particles in epoxy‐based composites, graft of glycidyl methacrylate (GMA) and styrene (St)/GMA onto the nanoparticles' surface was carried out in terms of emulsion polymerization method. The grafting polymers proved to be chemically attached to the nanoparticles via the double bonds introduced during the coupling agent pretreatment. The factors affecting the graft parameters, such as monomer concentration, initiator consumption, reaction time, etc., were investigated. It was shown that higher concentrations of monomer and initiator are favorable for the graft polymerization. When St/GMA was employed as the grafting monomer, the nanoparticles were found to play the role of polymerization loci. The grafted nanoparticles exhibit greatly improved dispersibility in cured epoxy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 992–999, 2006
Lipase‐catalyzed modification of konjac glucomannan
Authors: Chen Zhi‐Gang , Zong Min‐Hua , Li Guang‐Ji
Published: July 2006

Regioselective acylation of konjac glucomannan (KGM) with vinyl acetate in a solvent‐free system was successfully performed using Novozym 435 as a biocatalyst. The degree of substitution (DS) of the modified KGM was used to evaluate the extent of acylation. The influence of various factors, such as water activity (aw), reaction temperature, shaking rate, enzyme dosage, and the molecular weight of KGM, on the reaction was examined. The water activity of the reaction system played a key role in the acylation of KGM. The optimum water activity, reaction temperature, shaking rate, and enzyme dosage were 0.84, 50°C, 200 rpm and 400 U/mL, respectively. It has also been found that the DS of modified KGM sample decreases with increase in KGM molecular weight. Additionally, the acylation of KGM was shown to be regioselective, with acylation occurring at the C6OH. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1335–1340, 2006
A study on the moisture sorption characteristics in woven sisal fabric reinforced natural rubber biocomposites
Authors: Jacob Maya , Varughese K. T. , Thomas Sabu
Published: July 2006

Textile biocomposites were prepared by reinforcing natural rubber with woven sisal fabric. Sisal fabric was subjected to various chemical modifications like mercerization, silanization, and thermal treatment. The moisture uptake of the textile composites was found to depend upon fiber content as well as architecture. The mechanism of diffusion in the composites was found to be fickian in nature. The effect of chemical modification of sisal fabric on moisture uptake was also analyzed. Mercerization was seen to increase the water uptake in the composites while thermally treated fabric reinforced composites exhibited lower water uptake. The influence of temperature on water sorption of the biocomposites is also analyzed. The thermodynamic parameters of the sorption process were also evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 416–423, 2006
Effect of molecular weight on dielectric properties of polyvinyl alcohol films
Authors: Joshi Girish , Pawde S. M.
Published: July 2006

Impedance analysis is the best technique to reveal the microstructural details of the polymeric material. The dielectric polarization not only depends on physical and chemical properties, but also on the degree of polymerization (DP) of the polymeric material. In the present study, to understand the polarizing mechanism, two different molecular weights of polyvinyl alcohol (PVA) films were used for impedance analysis. Dielectric polarization of PVA film measured at normal temperature and pressure (NTP) condition by using LCR‐4282A Impedance analyzer, within the frequency range 20 Hz to 1 MHz. The importance of investigation is to know the simultaneous application of DC bias potential from 0 to 40 V with AC signal for measurement of over all electrical parameters. The result shows higher magnitude of dielectric constant for low‐molecular weight (LMW) of PVA film in comparison to higher molecular weight (HMW), which is based on Maxwell‐Wagner (M–W) theory. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1014–1016, 2006
Synthesis of tellurium containing syndiotactic polymethyl methacrylate using diphenyl ditelluride as a novel initiator
Authors: Tripathi Anjali , Srivastava Anil K. , Khandelwal Bishan L.
Published: July 2006

The synthesis of syndiotactic polymethyl methacrylate containing tellurium by using diphenyl ditelluride in the dioxan at (60 ± 0.1)°C for 2 h has been carried out. The presence of tellurium in the polymer has been confirmed qualitatively as well as by induced coupled plasma mass spectroscopy (ICP‐MS). The electron spin resonance spectrum shows the presence of TėPh, and value of gyromagnetic constant g has been calculated as 2.2203. The Tg of the polymer, measured by DSC, is 105°C. The syndiotactic nature has been confirmed by FTIR and NMR spectroscopy and DSC. The system follows ideal kinetics with activation energy 66 kJ mol−1. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1017–1022, 2006
Wood plastic composites by melt impregnation: Polymer retention and hardness
Authors: Zhang Yaolin , Zhang S. Y. , Chui Ying Hei , Wan Hui , Bousmina Mosto
Published: July 2006

Wood plastic composites were prepared through impregnation of solid wood with polyethylene. The effects of impregnation parameters on polymer retention and hardness were investigated. A screening strategy of 16‐run resolution IV design for seven factors at two levels was adopted. The seven factors were: ratio of maleated polyethylene in formulations, ratio of polyethylenes with different molecular weights, four process factors (vacuum, pressure, time, and temperature), and wood species (red maple and aspen). Polymer retention (PR) and Brinell hardness (HB) were investigated and discussed on the basis of the impregnation parameters. The present work showed that process parameters (pressure and temperature), polymer impregnants (different molecular weight polyethylenes), and wood species contributed significantly to PR and HB. Increasing pressure and temperature resulted in a higher PR and HB, whereas increasing the molecular weight of polyethylene and switching wood species from aspen to red maple gave a lower PR and HB. This study was aimed at understanding how impregnation parameters affect the final properties of wood plastic composites and developing an optimal fabrication process for wood plastic composites.
© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1672–1680, 2006
Preparation of porous poly(lactic acid)/Sio2 hybrid microspheres
Authors: Wang Hualin , Fang Mingshan , Shi Tiejun , Zhai Linfeng , Tang Chao
Published: July 2006

With 3‐aminopropyltriethoxysilane (APTES) as coupling agent, poly(lactic acid) (PLA)/SiO2 hybrid material was prepared to produce poly(lactic acid)/SiO2 hybrid microspheres (PLAHs) with porous structure bythe oil‐in‐water, single‐emulsion solvent evaporation method. Field scanning electron microscopy results show that the PLAHs were porous microspheres about 20 μm in diameter. The holes in the PLAHs opened outside and were not complicated. A nitrogen adsorption–desorption experiment showed that the nitrogen adsorbed in the holes was easily desorbed, and the specific surface area of the PLAHs was calculated to be 6.87 m2/g according to the Brunauer–Emmett–Teller equation. Fourier transform infrared spectroscopy results show that PLA was amidated with APTES successfully and formed a kind of organic–inorganic hybrid material by hydrolysis and con‐condensation with tetraethoxysilane. Moreover, the molecular structure of the hybrid material was confirmed by X‐ray photoelectron spectroscopy. Differential scanning calorimetry results show that the melting point ofthe PLAHs was higher than that of PLA by about 11.2°C. These PLAHs may be used in the controlled release of drugs by the embedding of the drugs in the holes of the PLAHs, and the drug loading amount can be controlled by the size and number of holes in the PLAHs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 679–683, 2006
Synthesis and characterization of polyurethane urea based on fluorine‐containing bisphenoxydiamine
Authors: Qin Xiu‐Min , Fang Fang , Yang Xiao‐Hui , Wang Xin‐Ling , Zheng Zhen
Published: July 2006

A fluorine‐containing bisphenoxydiamine, 2,2‐bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane (BAPF6P), was synthesized and characterized by means of Fourier transform infrared spectrometry (FTIR), NMR, and elemental analysis. The obtained BAPF6P was used as a chain extender to prepare polyurethane urea (PUU), whose morphology and properties were measured through FTIR, differential scanning calorimetry, thermogravimetric analysis, tensile measurements, and atomic force microscopy. The results show that the PUU elastomers based on BAPF6P exhibited good mechanical properties and thermal stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1863–1869, 2006
Synthesis, structure, and properties of new methacrylic derivatives of naphthalene‐2,3‐diol
Authors: Gawdzik Barbara , Podkościelna Beata , Bartnicki Andrzej
Published: July 2006

The synthesis of a new monomer, 2,3‐(2‐hydroxy‐3‐methacryloyloxypropoxy)naphthalene, and its copolymerization with divinylbenzene is presented. This monomer was obtained from naphthalene‐2,3‐diol in a two‐step synthesis. Copolymers in the form of porous microspheres were prepared by a suspension‐emulsion polymerization method. As pore‐forming diluents, toluene, 1‐decanol, benzyl alcohol, and their mixtures were used. In studies of their porous structure, two methods were used: the adsorption of nitrogen at low temperatures, which provided information about the porous structure of the material in a dry state, and inverse exclusion chromatography, which provided information about the porous structure of the polymer swollen by a good solvent. The obtained results suggest that the porous structures for the dry and swollen polymers were different. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1886–1895, 2006
Effect of geometry and surface properties of silicates on nanostructuration of suspension in precursors of an epoxy/amine network
Authors: Boukerrou Amar , Duchet Jannick , Fellahi Said , Sautereau Henry
Published: July 2006

Several lamellar silicates (Montmorillonite, Hectorite, Mica) showing different host structures and aspect ratios were modified with octadecylammonium ions by a cationic exchange process. The resulting organoclays were characterized using thermal gravimetric analysis and X‐ray diffraction, which allowed us to estimate the amount of surfactants within the organoclays and their organization in the interlamellar spacing. Some local pseudo‐organizations were found and checked by differential scanning calorimetry (DSC). The interactions of organophilic silicates were evaluated, without any shear, with the precursors of a rubbery epoxy/amine network. These silicate/monomers interactions were monitored via the measurements of the interlamellar swelling, the surface energies and the physical gel formation. The organoclays used form gels in the monomers above the percolation threshold if no shear is applied and present a gel/sol transition at a critical shear stress. Gel strength determined from storage modulus and viscosity values determined at high shear rates reveal different organizations of clay in the monomers depending on the silicate aspect ratio and silicate/monomers interactions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1380–1390, 2006
Abrasion phenomena in twill tencel fabric
Authors: Abdullah Iram , Blackburn Richard S. , Russell Stephen J. , Taylor Jim
Published: July 2006

The abrasion characteristics of Tencel fabrics were evaluated by Martindale abrasion and laundering, and the breakdown mechanism of fibers was surveyed by scanning electron microscopy. The fabric was subjected to pad‐dry‐cure treatment with two different types of modified dimethyloldihydroxyethylene urea resins (Reaktant DH and Reaktant FC). Although the degree of dry abrasion varied with different resins, the damage exhibited by individual fibers differed little from untreated to resin‐treated; the major mechanism of abrasion was through friction, and the mechanism of fiber failure was multiple splitting and transverse cracking. In untreated Tencel, the characteristic feature of wet abrasion was massive fibrillation, and in crosslinked fabrics, the wet abrasion mechanism was through fiber slippage and slicing action, although in the Reaktant FC‐treated fabric, the wet abrasion mechanism was more through slicing than through fiber splitting. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1391–1398, 2006
Synthesis and crystallization behavior of segmented copolyesters/silica composites
Authors: Zhao Yun Hui , Li Li‐Li , Yuan Xu‐Bo , Sheng Jing
Published: July 2006

Silica were introduced to segmented copolyester system (poly(butylene terephthalate)‐poly(ethylene terephthalate‐co‐isophthalate‐co‐sebacate) (PBT‐PETIS)) by in situ polymerization. Investigations on melting behavior and crystalline structure were undertaken, and the dispersion situation of silica in segmented copolyester composites was detected. A diverse crystallization characteristic has been found when the modified Avrami analytical method was applied to investigate nonisothermal crystallization behavior of the composites. Crystallization rate was restricted rather than be promoted by increasing loading of silica. The values of Avrami exponent ranged from 2.25 to 2.45, presenting a mechanism of three‐dimensional spherulitic growth with heterogeneous nucleation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1052–1058, 2006
Radiation crosslinking of biodegradable carboxymethylchitin and carboxymethylchitosan
Authors: Wasikiewicz J. M. , Mitomo H. , Nagasawa N. , Yagi T. , Tamada M. , Yoshii F.
Published: July 2006

Radiation induced crosslinking of carboxymethylchitin (CMCht) and carboxymethylchitosan (CMChts) has been investigated both by electron beam (EB) and γ‐irradiations. The highest crosslinking efficiency, measured as gel content of obtained hydrogels, by EB irradiation was 72 and 50% for CMCht and CMChts, respectively, at polymer concentration of 40% at room temperature. For irradiation crosslinking at different temperatures by γ‐irradiation, the best ratio of crosslinking to degradation processes was obtained at low temperature for low concentrated polymers and at high temperature for high concentrated ones. Both hydrogels revealed significant swelling properties in deionized water, with maximum water uptake 241.2 and 63 g water/g dry gel for CMCht and CMChts, respectively. Biodegradation tests, including enzymatic controlled microorganisms degradations and soil burial, have indicated that both hydrogels undergo spontaneous biodegradation with satisfactory results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 758–767, 2006
Fire‐retardant properties of the viscose rayon containing alkoxycyclotriphosphazene
Authors: Chen Sheng , Zheng Qing‐kang , Ye Guang‐dou , Zheng Guang‐kong
Published: July 2006

The viscose rayon containing cyclotriphosphazene were prepared by the method of blending spinning. The combustibility and thermal stability of the fire‐retardant viscose rayon were evaluated by 45 ° slope burning method, limit oxygen index (LOI), differential scanning calorimetry, thermogravimetry analysis. The results indicated that the LOI of the modified fiber could reach LOI ≥ 28, and the combustibility of the modified fiber could reach the fire‐retardant standard of Japan industry standard JIS 10 91–77 (times of ignition ≥ 3 times). The analysis of the fiber's thermal degradation suggested that the flame retardant plays a multirole of heat absorption, catalytic dehydration and carbonization, condensation‐phase and gas‐phase flame retardation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 698–702, 2006
γ‐Irradiation effects on the thermal and structural characteristics of modified, grafted polypropylene
Authors: Khalil Magda M. I. , El‐Sawy Naeem M. , El‐Shobaky Gamil A.
Published: July 2006

The effects of both the degree of grafting and γ irradiation on the thermal stability and structural characteristic of polypropylene‐graft‐polyvinylpyrrolidone and polypropylene‐graft‐polyvinylpyrrolidone modified with α‐cyano‐δ‐(2‐thienyl) crotononitrile were investigated. The employed techniques were thermogravimetric analysis, differential thermogravimetry, and X‐ray diffraction. The thermal stability of various polymeric substrates was investigated through the determination of the degradation temperature and activation energy of degradation. The effects of different parameters on the structural characteristics of different films were investigated through the determination of possible changes in the degree of ordering of the polymeric substrates. The results revealed that the thermal stability of the trunk polymer, grafted polymer, and polymer modified by α‐cyano‐δ‐(2‐thienyl) crotononitrile increased progressively with an increasing degree of grafting. The increase was, however, more pronounced for the sample undergoing the lowest degree of grafting. The activation energy of the thermal degradation process remained almost unchanged, and this indicated that the degradation processes of the different films followed almost the same mechanism. The γ irradiation at a dose of 60 kGy of the sulfur‐treated polymeric films [i.e., the polymeric films treated with α‐cyano‐δ‐(2‐thienyl) crotononitrile] reduced their thermal stability. This conclusion was reached by the consideration of the changes observed in the pre‐exponential factor of the Arrhenius equation due to different chemical and γ‐irradiation treatments. The degree of ordering, evidenced by X‐ray diffraction measurements of the trunk polymer, grafted polymer, and modified polymer, suffered a significant drop. This drop was much more pronounced for the sulfur‐containing polymeric materials. The observed drop in the degree of ordering of the polymeric substrates was taken as a measure of the structure collapse due to a certain treatment (degree of grafting and sulfur inclusion). The γ irradiation of the sulfur‐containing polymeric materials greatly increased their degree of ordering, which reached a value greater than that measured for the trunk polymer. Therefore, it was concluded that the thermal stability increased as the degree of ordering decreased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 506–515, 2006
Synthesis of polyethylene oxide hydrogels by electron radiation
Authors: Branca C. , Magazù S. , Maisano G. , Auditore L. , Barnà R. C. , De Pasquale D. , Emanuele U. , Trifirò A. , Trimarchi M.
Published: July 2006

Poly(ethylene oxide) (PEO) hydrogels were prepared by crosslinking of aqueous PEO 35,000 solutions at a 30% concentration by using electron irradiation. Measurements were performed at different dose rates and irradiation doses. The swelling properties of each sample have been investigated and the network properties of the PEO hydrogels calculated. In particular, the effect of dose rate and dose irradiation on the crosslinking density were investigated. Finally, the experimental results illustrating the effects of the beam parameters on the network properties for a pulsed irradiation are compared to those of a continuum beam. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 820–824, 2006
Ion exchange properties of carboxylated bagasse
Authors: Nada Abd‐Allah M. A. , Hassan Mohammad L.
Published: July 2006

Bagasse fibers were chemically modified with the aim to prepare lignocellulosic materials that have the ability to remove heavy metal ions from waste water. Three different reactions were used for the modification: etherification using monochloroacetic acid, esterification using succinic anhydride, and oxidation using sodium periodate and sodium chlorite. Bagasse was crosslinked using epichlorohydrin before chemical modification to avoid loss of its constituents during the chemical modification or application. The structure of the prepared derivatives was proofed using Fourier transform infrared and chemical methods. The ability of the prepared bagasse cation exchangers to adsorb heavy metal ions (Cu2+, Ni2+, Cr3+, Fe3+), on a separate basis or in a mixture of them, at different metal ion concentration was tested. Thermal stability of the different bagasse derivatives was studied using thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1399–1404, 2006
ABA triblock copolymers from poly(p‐dioxanone) and poly(ethylene glycol)
Authors: Yang Ke‐Ke , Zheng Li , Wang Yu‐Zhong , Zeng Jian‐Bing , Wang Xiu‐Li , Chen Si‐Chong , Zeng Qiang , Li Bin
Published: July 2006

Poly(p‐dioxanone)–poly(ethylene glycol)–poly(p‐dioxanone) ABA triblock copolymers (PEDO) were synthesized by ring‐opening polymerization from p‐dioxanone using poly(ethylene glycol) (PEG) with different molecular weights as macroinitiators in N2 atmosphere. The copolymer was characterized by 1H NMR spectroscope. The thermal behavior, crystallization, and thermal stability of these copolymers were investigated by differential scanning calorimetry and thermogravimetric measurements. The water absorption of these copolymers was also measured. The results indicated that the content and length of PEG chain have a greater effect on the properties of copolymers. This kind of biodegradable copolymer will find a potential application in biomedical materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1092–1097, 2006
Transverse alignment of liquid crystalline epoxy resin on carbon fiber surface
Authors: Lee Jun Yeob
Published: July 2006

Transverse alignment of liquid crystalline epoxy (LCE) resin was effectively induced on carbon fiber (CF) surface by amine treatment. Aliphatic and aromatic amines were grafted on oxidized CF surface, and anisotropic orientation of LCE network was identified with X‐ray diffraction and it was correlated with mechanical properties of CF/LCE composites. Vertical alignment of LCE enhanced the transverse dynamic modulus of the composite. Especially, aromatic diamines were effective in promoting the interfacial adhesion as well as transverse composite modulus. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 684–689, 2006
Solvents effect in horseradish peroxidase catalyzed modification of UHMWPE fiber
Authors: Fan Guoning , Zhao Jingchan , Yuan Hongan , Guo Zhian , Wang Junlong , Liang Guozheng
Published: July 2006

Graft copolymerization of acrylamide onto ultrahigh molecular weight polyethylene (UHMWPE) using horseradish peroxidase as catalyst was performed in different reaction solution to study the solvent effect. The factors affecting the grafting effect such as the solvents composition, initiator, reaction temperature, and reaction time were investigated. The grafted UHMWPE fiber surface was characterized by IR spectrum, scanning electron microscopy, thermal analysis, contact angle measurement, and single fiber pull out test. Polar groups such as CO and NH2 are approved to appear on the surface after treatment. The contact angle with water decreased from 85 to 50, indicating the wettability of the fiber has been increased. The surface of the grafted fiber became rougher and its adhesion to resin increased significantly, and hence is expected to produce reinforced plastics with resin. It was also found that the grafting effect was higher in dioxane than in other solvents used and the initiator substituted by electron donating group facilitates the grafting reaction. And the optimum reaction condition was determined to be reacting in 40% (v/v) dioxane solution at 30°C for 2 h. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 674–678, 2006
Preparation and characterization of poly(vinyl chloride)/layered double hydroxides nanocomposite via in situ suspension polymerization
Authors: Bao Yong‐Zhong , Huang Zhi‐Ming , Weng Zhi‐Xue
Published: July 2006

Poly(vinyl chloride)/layered double hydroxides (PVC/LDHs) composite resins were prepared by in situ suspension polymerization of vinyl chloride monomer in the presence of LDHs intercalated with dodecyl sulfate anions (LDH‐DS), and were further processed to obtain PVC/LDH‐DS nanocomposites. It was found that the mean particle size of PVC composite resins decreased as LDH‐DS was added in the polymerization system. The 5 and 10% weight loss temperatures of PVC resins significantly increased with the increase of LDH‐DS weight fraction in the composite resins. The transmission electron microscopy images showed that LDH‐DS particles were partially intercalated and partially exfoliated, and well distributed in the PVC nanocomposites. The storage modulus below the glass transition region and the glass temperature of the PVC/LDH‐DS nanocomposites are greater than that of the pristine PVC. The mechanical properties of PVC/LDH‐DS nanocomposites indicate that LDH‐DS nanoparticles stiffen and toughen PVC. The tensile strength, Young's modulus, and Charpy notched impact strength of the PVC/LDH‐DS nanocomposites are greater than those of the pristine PVC and PVC/LDH‐DS composites prepared by the melt blending. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1471–1477, 2006
Electron beam synthesis and characterization of poly(vinyl alcohol)/montmorillonite nanocomposites
Authors: Abd Alla Safaa G. , Nizam El‐Din Horia M. , El‐Naggar Abdel Wahab M.
Published: July 2006

Poly(vinyl alcohol) (PVA)/montmorillonite clay (MMT) nanocomposites in the form of films were prepared under the effect of electron beam irradiation. The PVA/MMT nanocomposites gels were characterized by X‐ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and mechanical measurements. The study showed that the appropriate dose of electron beam irradiation to achieve homogeneous nanocomposites films and highest gel formation was 20 kGy. The introduction of MMT (up to 4 wt %) results in improvement in tensile strength, elongation at break, and thermal stability of the PVA matrix. In addition, the intercalation of PVA with the MMT clay leads to an impressive improved water resistance, indicating that the clay is well dispersed within the polymer matrix. Meanwhile, it was proved that the intercalation has no effect on the metal uptake capability of PVA as determined by a method based on the color measurements. XRD patterns and SEM micrographs suggest the coexistence of exfoliated intercalated MMT layers over the studied MMT contents. The DSC thermograms showed clearly that the intercalation of PVA polymer with these levels of MMT has no influence on the melting transitions; however, the glass transition temperature (Tg) for PVA was completely disappeared, even at low levels of MMT clay. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1129–1138, 2006
Concentrated emulsion polymerization for preparation of β‐cyclodextrin‐supported chromatography columns
Authors: Baharvand H. , Zeynali M. E. , Rabiee A.
Published: July 2006

Concentrated inverse emulsion polymerization was used for making chromatography columns (based on crosslinked polystyrene divinylbenzene (PS‐DVB)) with pore sizes less than 10 μm. According to DSC‐thermal gravimetry thermograms, it was confirmed that the residual monomer concentration after polymerization process is negligible. For application of these columns in chiral chromatography, the β‐cyclodextrin is chemically fixed on the PS‐DVB resin pore surface. The presence of hydroxyl groups in the PS‐DVB resin after chemical modification was confirmed by FTIR spectroscopy. By chemical modification of the PS‐DVB resin, thermal stability increased up to 446°C. The structure of columns was analyzed by scanning electron microscopy (SEM). SEM evaluations showed that the porous structure of PS‐DVB resin was maintained intact after the chemical modification with β‐cyclodextrin. According to X‐ray data, presence of the crystalline domain that is related to β‐cyclodextrin is confirmed.© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 857–863, 2006