bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modification of cellulase with polyalkylene oxide allyl ester–maleic acid anhydride copolymer and its application to the pulp and paper industry
Authors: Park Kwinam , Park Jinwon , Lee Ju‐Han 
Published: October 2004

AbstractFunctional copolymer‐modified cellulase was applied to newspaper reprocessing. The new copolymers, composed of polyalkylene oxide (PAO) and maleic acid anhydride (MA), were synthesized to modify the cellulase. MA was attached to PAO allyl ester, formed by the reaction between PAO allyl alcohol and lauric acid. The modification is produced by the ability of MA to react with the amino acid group of the cellulase for modification. At the maximum degree of modification of 52%, modified cellulase showed more than 65% activity over the unmodified native cellulase. When modified cellulase was applied to the waste paper reprocessing, it was found that the cellulase enhanced the detachment of ink particles from paper. PAO was found to also cause the removal of the detached ink particles by floatation. This process creates a more moderate environment than conventional methods, improves the physical properties of the paper such as freeness and whiteness in comparison to conventional NaOH methods, while maintaining the same ink particle removal ability. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 894–899, 2002; DOI 10.1002/app.10088
Synthesis and characteristics of chelating fibers containing imidazoline group or thioamide group
Authors: Liu Ruixia , Li Yi , Tang Hongxiao 
Published: October 2004

AbstractTwo types of chelating fibers containing an imidazoline or thioamide group were prepared through the functionalization of hydrazine‐modified polyacrylonitrile fiber by ethylenediamine and through the amination and sulfurization reaction of the hydrazine‐modified polyacrylonitrile fiber under appropriate conditions, respectively. It is shown that the reaction temperature, time, and agent concentration are the dominant factors in the synthesis of fibrous sorbents. The increase of the ethylenediamine concentration from 33 to 45% (v/v) at 95–98°C results in a twofold higher increase of the fibrous sorbent with the imidazoline group, and a doubling of the reaction time from 2 to 4 h leads to a weight increase of the fibrous sorbent from 10 to 25% (w/w). Raising the temperature by about 5°C significantly accelerates the amination reaction of the hydrazine‐modified fiber, but the temperature is an insensitive factor in the thioamide‐functionalized reaction of the aminated fiber. The introduction of a thioamide or imidazoline group is further verified by IR spectroscopy analysis. X‐ray diffraction spectroscopy indicates the absolute disappearance of crystalline peaks for the fibers containing an imidazoline or thioamide group. However, the crosslinking reaction of the polyacrylonitrile fiber by hydrazine may make up for the effect of the crystallinity on the mechanical strength of the fibers, and the surface crackles of fibrous sorbents are not found by SEM photographs. The adsorption experiment results show that the newly prepared sorbents have high sorption capacities for noble metals in a high acidity, and it is also proved that Au(III) loaded on the chelating fibers may be reduced to Au(0). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1608–1616, 2002
Effect of reactive polyurethane on toughness of unsaturated polyester resin
Authors: Min Kyung‐Eun , Hwang Yeong‐Geun , Choi Gwan‐Young , Kim Ho‐Gyum , Kim Woo‐Sik , Lee Dong‐Ho , Park Lee‐Soon , Seo Kwan‐Ho , Kang Inn‐Kyu , Jun Il‐Ryun , Lim Jeong‐Cheol , Song Han‐Chul 
Published: October 2004

AbstractUnsaturated polyester (UP) resin is one of the major thermosetting resins and is very useful as a matrix resin of composite material for its processibility. UP resin, however, has several shortcomings: it is weak in alkalis, volume shrinkage occurs during the crosslinking reaction of the oligomeric UP resin with a styrene monomer, and it is also brittle. The mechanical properties of UP resin can be enhanced by blending it with various materials. In this study, polyurethane (PU) was used as a modifier to improve the toughness of the UP resin. The effect of the polyol molecular weight as a PU soft segment and the PU contents on the toughness of PU‐modified UP resins were studied. A UP/PU polymer network may occur through a reaction between an isocyanate group in the methyl diisocyanate (MDI) and a hydroxyl one in the UP molecules. The maximum toughness was observed at approximately 2 wt % of the PU content. These results can be rationalized by the incorporation of a rubbery PU segment into a brittle UP resin. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 84: 735–740, 2002; DOI 10.1002/app.10169
Iodination of plasticized poly(vinyl chloride) in aqueous media via phase transfer catalysis
Authors: Lakshmi S. , Jayakrishnan A. 
Published: October 2004

AbstractNucleophilic substitution of chlorine on plasticized poly(vinyl chloride) (PVC) was carried out using potassium iodide (KI) in the presence of a phase transfer catalyst (PTC) in aqueous media. Iodination was confirmed using energy dispersive X‐ray analysis (EDAX). The extent of iodination was studied with respect to time, temperature, concentration of the reactants, as well as different PTCs. Among the different PTCs examined, tetrabutylammonium bromide (TBAB) and tetrabutylammonium hydrogen sulfate (TBAH) were found to be highly efficient for the reaction. About 25% increase in weight was observed for PVC sheets iodinated under optimal reaction conditions. The thermal stability of the modified PVC was found to be impaired upon iodination. The iodinated PVC released iodide ions when kept in distilled water, as evidenced by UV spectroscopy. Sustained release of iodide ion in distilled water was followed up for about 30 days. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 493–499, 2002; DOI 10.1002/app.10176
Preparation and characterization of interpenetrating network beads of poly(vinyl alcohol)‐grafted‐poly(acrylamide) with sodium alginate and their controlled release characteristics for cypermethrin pesticide
Authors: Kumbar Sangamesh G. , Aminabhavi Tejraj M. 
Published: October 2004

AbstractInterpenetrating network polymeric beads of poly(vinyl alcohol)‐grafted‐acrylamide with sodium alginate have been prepared by crosslinking with glutaraldehyde. Cypermethrin, a widely used pesticide, was loaded with 80% efficiency in these hydrogel beads. The beads were characterized by Fourier transform infrared spectroscopy to confirm the grafting. Scanning electron microscopy was used to know the morphology of the beads. Equilibrium swelling experiments indicated that swelling of the beads decreased with an increase in crosslinking. The in vitro release studies were performed under static conditions and the release data have been fitted to an empirical relation to estimate the transport parameters. The diffusion coefficients have been calculated for the transport of pesticide through the polymeric beads using the initial time approximation method. These values showed decrease with increasing crosslinking as well as increasing pesticide loading. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 552–560, 2002; DOI 10.1002/app.10306
Synthesis and characterization of block copolymers containing PC segments and PHTH‐6 mesogenic units
Authors: Zhao Xiongyan , Hu Xiao , Yue Chee Yoon , Zhang Huijing , Zhou Qixiang 
Published: October 2004

AbstractLiquid crystalline block copolymers that incorporate both PHTH‐6 mesogenic units and polycarbonate (PC) segments in the main chain were synthesized by polycondensation in solution of hydroxyl‐terminated PC and acid‐chloride‐terminated PHTH‐6. The copolymer compositions were determined from 1H‐NMR data. The structure, thermal properties, as well as liquid crystalline behavior of the block copolymers were characterized by 1H‐NMR, Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), polarizing optical microscopy (POM), transmission electron microscopy (TEM), and X‐ray scattering, etc. A novel kind of morphology of a liquid crystalline block copolymer, a feathery structure, was observed for the first time, in which the PHTH‐6 mesogenic microphase dispersed in the PC microdomain in the form of feathery structure. These block copolymers showed a microphase‐separation system, for which the geometry on a length scale changes from tens of nanometers to 600 nm and the degree of phase separation was strongly dependent on the segment lengths incorporated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 283–294, 2002; DOI 10.1002/app.10318
Synthesis and properties of agglomerating agent for high‐solids NBR latices
Authors: Cho Kyo Dong , Jang Killsoo , Yang Gun‐Ho , Chang Jin Gyu , Ha Ki Ryong , Park Jong Woo , Park Lee Soon , Song Sang Moo 
Published: October 2004

AbstractAgglomerating agents were synthesized in a latex form utilizing a seeded emulsion polymerization method to get high solid content NBR latex without exhibiting excessively high viscosity and unstability in the concentration process. An agglomerating agent synthesized with ethylacrylate in the core part and methacrylamide as the hydrophilic monomer in the shell effectively increased the average size of the NBR base latex when it was mixed with the NBR latex and settled for about 2 h. The NBR latex, treated with the proper amount of an agglomerating agent, could be concentrated up to 60.5 wt % solid, while an untreated NBR latex could only be concentrated to 45.0 wt % solid due to the viscosity buildup. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 276–282, 2002; DOI 10.1002/app.10325
Copolymerization of ethylene/propylene elastomer using high‐activity Ziegler–Natta catalyst system of MgCl2 (ethoxide type)/EB/PDMS/TiCl4/PMT
Authors: Zohuri G. H. , Sadegvandi F. , JamJah R. , Ahmadjo S. , Nekoomanesh M. , Bigdelli E. 
Published: October 2004

AbstractA high‐activity Ziegler–Natta catalyst of TiCl4‐supported MgCl2 (ethoxide type) was prepared. Ethyl benzoate (EB) and polydimethylsiloxane (PDMS) were used as internal donors, while p‐methyl toluate (MPT) and triethylaluminum (TEA) were used as the external donor and cocatalyst, respectively. Suspension copolymerization of ethylene–propylene (EPM) was carried out in n‐heptane using the catalyst system. The relative pressures of 1.5 : 1 and 2 : 1 atmosphere of propylene‐to‐ethylene (PP/PE) gave a polymer with elastomeric properties. The relative pressure of propylene‐to‐ethylene higher and lower than the above values, however, gave a homopolymer or copolymer without elastomeric properties. The effect of the TEA concentration, H2 concentration, temperature, and pressure of PP/PE on the yield of the polymer obtained was investigated. The effects of these factors on the glass transition temperature (Tg) and ethylene content of the polymer were studied. The content of ethylene in EPM was determined using the FTIR technique. The molar ratio of Al : MPT : Ti = 355 : 107 : 1 gave a polymer with an ethylene content of about 32%. However, a ratio lower than AL : MPT : Ti = 355 : 107 : 1 did not give a good elastomeric polymer. The highest productivity of the catalyst was obtained at a molar ratio of AL : MPT : Ti = 355 : 107 : 1. Increasing the temperature from 45 to 70°C caused a slight increase of Et % content and a decrease of the Tg of the copolymer obtained, while the highest productivity of the catalyst was obtained at 55°C with good elastomeric properties using an AL : MPT : Ti = 497 : 107 : 1 molar ratio. Increasing the pressure of propylene from 1.5 to 2.5 atm caused a sharp decrease in the Tg and ethylene content of the polymer. When the ethylene content in the copolymer was increased, the Tg value had a tendency to be closer to the polyethylene Tg. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 84: 785–790, 2002; DOI 10.1002/app.10330
Prediction of the release characteristics of alcohols from EVA using a model based on Fick's second law of diffusion
Authors: Krüger Arnoldus J. , Tolmay Andries T. 
Published: October 2004

AbstractThis study evaluates the use of a simple mathematical model to predict release characteristics of volatile substances from polymer dispensers. The model can be used to simplify the design process of polymer dispensers, which is traditionally done by trial and error. The coefficients of diffusion, D, of four alcohols through EVA disks were determined with the time lag technique. The value of D was used to predict the residual mass of dispensers over time using a model based on Fick's second law of diffusion. Injection‐molded dispensers containing 10% alcohol were prepared, and the release of the alcohol were monitored experimentally. The modeled results were compared to the experimental results. A good correlation was found between the predictions and the experimental results. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 84: 806–813, 2002; DOI 10.1002/app.10333
Effect of processing conditions on the yield and failure response of an aliphatic polyketone terpolymer
Authors: Karttunen Nicole R. , Lesser Alan J. 
Published: October 2004

AbstractThe effect of processing conditions on the yield and failure behavior of an aliphatic polyketone terpolymer was studied. Testing and characterization were performed on samples that were extruded in the form of hollow cylinders. We performed the extrusion process at different shear rates and at different cooling rates to assess the effect that process conditions had on the polymer properties. We performed biaxial testing on the samples to characterize the failure envelopes, including the ductile–brittle transition condition for each process condition. The effect of shear rate was negligible, whereas the cooling rate significantly affected the failure behavior. To explain these differences in behavior, we performed characterization via differential scanning calorimetry, wide‐angle X‐ray diffraction, attenuated total reflection IR spectroscopy, dynamic mechanical thermal analysis, scanning electron microscopy, and residual stress measurements. A broad glass transition was found for all samples at temperatures higher than previously reported for this material. Alteration of the processing conditions did not influence the crystalline phase (percentage crystallinity, crystalline orientation, crystallite size, etc.). A change in spherulitic structure was also observed with altered cooling rate and is suggested to have contributed to the change in failure behavior. Residual stresses also affected the behavior of all samples. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 318–334, 2002; DOI 10.1002/app.10334
Chemical modification of 3,3′,4,4′‐biphenyltetracarboxylic dianhydride polyimides by a catechol‐derived bis(ether amine)
Authors: Yang Chin‐Ping , Hsiao Sheng‐Huei , Chen Ruei‐Shin , Wei Chi‐Shu 
Published: October 2004

AbstractHaving previously demonstrated that the polyimide derived from 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA) and 1,2‐bis(4‐aminophenoxy)benzene [termed triphenyl ether catechol diamine (TPEC)] exhibited superior tensile properties in addition to good thermal properties, we now provide a preliminary assessment of the properties of the copolyimides prepared from BPDA, TPEC, and another aromatic diamine. The homopolyimides derived from BPDA and many aromatic diamines generally possessed good mechanical properties and thermal properties; however, they were insoluble in available organic solvents. In several cases, organosoluble BPDA copolyimides could be prepared from BPDA and equimolar mixtures of TPEC and another aromatic diamine. All the copolyimides could be formed into tough films with high moduli and strengths and, in most cases, high extensions to break. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 351–358, 2002; DOI 10.1002/app.10342
Energy‐transfer method to study vapor‐induced latex film formation
Authors: Pekcan Ö. , Adiyaman N. , Uğur Ş. 
Published: October 2004

AbstractNonradiative energy transfer method was used to study latex film formation induced by organic solvent vapor. Seven different films with the same latex content were prepared separately from poly(methyl methacrylate) (PMMA) particles and exposed to ethyl benzene, toluene, chloroform, dichloromethane, tetrahydrofuran, and acetone vapor in seven different experiments. Energy‐transfer experiments were carried out between PMMA‐bound naphthalene (N) and pyrene (P) during vapor‐induced film formation. Latex films were prepared from equal amounts of N‐ and P‐labeled latex particles, and steady state spectra of N and P were monitored during film formation. It was observed that the P to N intensity ratio, IP/IN, increased as the vapor exposure time increased. The Prager–Tirrell (PT) model was employed to obtain back‐and‐forth frequencies, ν, of the reptating PMMA chains during latex film formation induced by solvent vapor. ν values were obtained and found to be correlated with the solubility parameter, δ. Polymer interdiffusion obeyed the t1/2 law during film formation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 632–645, 2002; DOI 10.1002/app.10346
Toughening of cycloaliphatic epoxy resins by poly(ethylene phthalate) and related copolyesters
Authors: Iijima Takao , Fujimoto Ken‐Ichiro , Tomoi Masao 
Published: October 2004

AbstractPoly(ethylene phthalate) (PEP) and poly(ethylene phthalate–co‐ethylene terephthalate) were used to improve the brittleness of the cycloaliphatic epoxy resin 3,4‐epoxycyclohexylmethyl 3,4‐epoxycyclohexane carboxylate (Celoxide 2021™), cured with methyl hexahydrophthalic anhydride. The aromatic polyesters used were soluble in the epoxy resin without solvents and effective as modifiers for toughening the cured epoxy resin. For example, the inclusion of 20 wt % PEP (MW, 7400) led to a 130% increase in the fracture toughness (KIC) of the cured resin with no loss of mechanical and thermal properties. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behaviors of the modified epoxy resin system. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 388–399, 2002; DOI 10.1002/app.10363
Toughening of vinylester–urethane hybrid resins through functionalized polymers
Authors: Gryshchuk O. , Jost N. , Karger‐Kocsis J. 
Published: October 2004

AbstractLiquid nitrile rubber, hyperbranched polyester, and core/shell rubber particles of various functionality, namely, vinyl, carboxyl, and epoxy, were added up to 20 wt % to a bisphenol‐A‐based vinylester–urethane hybrid (VEUH) resin to improve its toughness. The toughness was characterized by the fracture toughness (Kc) and energy (Gc) determined on compact tensile (CT) specimens at ambient temperature. Toughness improvement in VEUH was mostly achieved when the modifiers reacted with the secondary hydroxyl groups of the bismethacryloxy vinyl ester resin and with the isocyanate of the polyisocyanate compound, instead of participating in the free‐radical crosslinking via styrene copolymerization. Thus, incorporation of carboxyl‐terminated liquid nitrile rubber (CTBN) yielded the highest toughness upgrade with at least a 20 wt % modifier content. It was, however, accompanied by a reduction in both the stiffness and glass transition temperature (Tg) of the VEUH resin. Albeit functionalized (epoxy and vinyl, respectively) hyperbranched polymers were less efficient toughness modifiers than was CTBN, they showed no adverse effect on the stiffness and Tg. Use of core/shell modifiers did not result in toughness improvement. The above changes in the toughness response were traced to the morphology assessed by dynamic mechanical thermal analysis (DMTA) and fractographic inspection of the fracture surface of broken CT specimens. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 672–680, 2002; DOI 10.1002/app.10392
Copolymerization of ethylene/nonconjugated dienes over a Bis(2‐methyl indenyl) zirconium dichloride/methylaluminoxane catalyst system
Authors: Jin Hyoung‐Joon , Choi Chang‐Ho , Park Eun‐Soo , Lee Ik‐Mo , Yoon Jin‐San 
Published: October 2004

AbstractEthylene was copolymerized with 1,5‐hexadiene (1,5‐HD), 1,4‐hexadiene (1,4‐HD) and 1,7‐octadiene (1,7‐OD) with bis(2‐methyl indenyl) zirconium dichloride/methylaluminoxane. 1,5‐HD units formed the trans‐structured cyclopentane rings and 1‐butenyl side chains, and cross‐linking took place during ethylene/1,5‐HD (E15HD) copolymerizations. The lower the polymerization temperature was, the larger the amount of hot xylene (XYL)‐insoluble faction was. Copolymers of ethylene/1,7‐OD (E17OD) did not have any cyclic structures and were nearly insoluble in XYL when produced below 60°C. In contrast, all the copolymers of ethylene/1,4‐HD (E14HD) were completely soluble in XYL. The broadest differential scanning calorimetry melting peak was found for E15HD and then for E17OD, and the narrowest was found for E14HD due to the presence or the absence of the cyclic structures and cross‐linking. Addition of 1,7‐OD or 1,4‐HD as a comonomer reduced the polymerization rate and the molecular weight of the respective copolymers much more than that of 1,5‐HD. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1048–1058, 2002; DOI 10.1002/app.10397
Functional, uniform, and macroporous latex particles: Preparation, electron microscopic characterization, and nonspecific protein adsorption properties
Authors: T. Çamli  , Tuncel M. , Şenel S. , Tuncel A. 
Published: October 2004

AbstractA series of uniform, macroporous particles with different surface chemistries were prepared with different acrylic comonomers [methyl methacrylate (MMA), butyl methacrylate (BMA), epoxypropyl methacrylate (EPMA), 2‐hydroxyethyl methacrylate (HEMA), and methacrylic acid (MAA)] with styrene–divinylbenzene (S–DVB) in a multistep seeded polymerization. In the synthesis, uniform polystyrene seed particles 6.2 μm in size were swollen first with a low molecular weight organic agent and then with a monomer phase including an S–DVB mixture and a relatively polar acrylic monomer. Final macroporous particles approximately 10 μm in size were obtained by the repolymerization of the monomer phase in the swollen seed particles. Surface and bulk morphologies were investigated with scanning and transmission electron microscopy, respectively. Although highly porous particles could be achieved with relatively hydrophobic monomers such as styrene, BMA, MMA, and EPMA, the use of hydrophilic monomers such as HEMA and MAA led to the synthesis of uniform particles with lower macroporosity. A comparison of Fourier transform infrared and Fourier transform infrared/diffuse reflectance spectroscopy spectra indicated that the concentration of polar acrylic monomer on the surface was higher than in the bulk structure. The nonspecific protein adsorption behavior of uniform, macroporous particles was investigated with albumin as a model protein. The highest nonspecific albumin adsorption was observed with plain poly(styrene‐co‐divinylbenzene) [poly(S–DVB)] particles. The particles produced with MMA and EPMA also exhibited albumin adsorption capacities very close to that of plain poly(S–DVB). Reasonably low nonspecific albumin adsorption was observed with the particles produced in the presence of MAA, HEMA, and BMA. Poly(S–DVB) particles functionalized with poly(vinyl alcohol) provided nearly zero nonspecific albumin adsorption. For nonspecific albumin binding onto the particles via a physical adsorption mechanism, desorption ratios higher than 80% could be achieved. The desorption ratio with the EPMA‐carrying particles was only 5% because the albumin adsorption onto EPMA‐carrying particles occurred predominantly with covalent‐bond formation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 414–429, 2002; DOI 10.1002/app.10412