bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and properties of transparent and conducting nylon 6‐based composite films
Authors: Im Sung Soon , Byun Sung Weon 
Published: April 2003

AbstractHighly transparent and conducting polypyrrole–(PPy–N) and polyaniline–nylon 6 (PAN) composite films could be easily obtained by immersing nylon 6 films containing pyrrole or aniline into an oxidant solution such as aqueous FeCl3 solution or aqueous (NH4)2S2O8 solution containing HCl. The conductivity, transmittance, and mechanical properties of these composite films were affected by the preparative conditions. The maximum conductivity and transmittance of the PPy–N composite films were 10−3 S/cm and about 75% at 550 nm, and in the case of the PA–N composite films, 10−2 S/cm and 75%, respectively. The morphology of PPy–N and PA–N composite films depended on the polymerization conditions, which might be due to the difference in the polymerization speed of pyrrole or aniline in polymer matrices. These PPy–N and PA–N composite films exhibited good environmental stability and excellent mechanical properties. © 1994 John Wiley & Sons, Inc.
Polarized internal reflectance spectroscopic studies of oriented poly(ethylene terephthalate)
Authors: Lofgren E. A. , Jabarin S. A. 
Published: April 2003

AbstractPolarized internal reflectance spectroscopy (IRS) has been used to evaluate molecular orientation and crystallinity of poly(ethylene terephthalate) film surfaces. Measurements were taken using samples stretched in both uniaxial and biaxial modes. All bands of interest were normalized with a reference band near 1410 cm−1, resulting from phenylene ring vibrations. Normalization was performed in order to overcome problems with sample contact and effective thickness. Results obtained using bands representing trans and gauche rotational isomers, present, respectively, at 1340 and 1370 cm−1, have been related to data acquired using density and birefringence techniques. The polarized IRS technique discussed is well suited for investigations of polymer orientation and crystallinity, since it avoids limitations related to sample thickness and clarity imposed by polarized transmission infrared spectroscopy. Parameters such as orientation functions, attenuation indices, dichroic ratios, and structural factors have been determined from data collected in each of the three spatial directions. Results are correlated with corresponding density, birefringence, and refractive index values and are found to give good agreement with these methods. © 1994 John Wiley & Sons, Inc.
Cold‐setting wood adhesives from kraft hardwood lignin
Authors: Truter P. , Pizzi A. , Vermaas H. 
Published: April 2003

AbstractThe model compound used in this study, for hardwood kraft lignin, 3,5‐dimethoxy‐4‐hydroxyphenyl ethane, was successfully hydroxymethylated at the position meta to the aromatic hydroxy group. The consequent expectation that kraft hardwood lignin syringyl units can, under optimum conditions, also be hydroxymethylated to a substantial extent was confirmed in the present work and made it possible to cross‐link the kraft hardwood lignin to yield polymeric products that could be used as adhesives. © 1994 John Wiley & Sons, Inc.
Transport of small molecules in polyolefins. III. Diffusion of topanol CA in ethylene polymers
Authors: Földes Enikó 
Published: April 2003

AbstractTransport properties of Topanol CA, [1,1,3‐tris(2‐methyl‐4‐hydroxy‐5‐tert‐butyl‐phenyl)‐butane], were studied in low‐density polyethylene (LDPE), in a blend of low‐density and linear low‐density polyethylenes (LDPE/LLDPE) and in ethylene vinyl acetate copolymer (EVA). The rate of diffusion (D) was evaluated on the free‐volume theory basis. A linear relationship was obtained between In D and the reciprocal fractional free volume of the noncrystalline phase of the polymers. Solubility of the additive is higher in EVA than in polyethylene. Compatibility of Topanol CA with ethylene polymers is poor, the measured solubility values depend on the experimental conditions and thermal history of the additive source. © 1994 John Wiley & Sons, Inc.
A study of coating properties of novel poly(amino‐quinone)s prepared from 2‐methylbenzoquinone and 2‐phenylbenzoquinone
Authors: Reddy T. Ashok , Erhan S. 
Published: April 2003

AbstractNovel poly(amino‐quinone)s were quantitatively prepared from in situ produced 2‐methylbenzoquinone and 2‐phenylbenzoquinone with Jeffamine D‐400® in the presence of calcium hypochlorite as the oxidizing agent. These polymers were readily soluble in most of the organic solvents such as ethanol, acetone, tetrahydrofuran, chloroform, N,N‐dimethylformamide (DMF), N‐methyl‐2‐pyrrolidone (NMP), and N,N‐dimethylacetamide (DMAc). The coatings prepared from these polymers showed very good adhesion to metals, hardness, and flexibility even after curing at 110°C for 5 h. Particularly, coatings formulated with epoxy‐novalac resin D.E.N‐438 showed excellent corrosion resistance in artificial sea water and did not form any blisters. © 1994 John Wiley & Sons, Inc.
Curl‐free high‐adhesion polyimide/copper laminate
Authors: Chen H. L. , Ho S. H. , Wang T. H. , Chen K. M. , Pan J. P. , Liang S. M. , Hung Aina 
Published: April 2003

Abstract6‐Amino‐2‐(p‐aminophenyl) benzimidazole (BIA) was synthesized and empolyed as a diamine component in the preparation of polyamic acid. The mechanical and thermal properties of polyimides made from BIA as a diamine component were investigated. A highadhesion, curl‐free polyimide/copper laminate has been obtained by using BIA as a diamine component. © 1994 John Wiley & Sons, Inc.
Interaction of dyes used for foods with food packaging polyester fibers
Authors: Arvanitoyannis I. , Tsatsaroni E. , Psomiadou E. , Blanshard J. M. V. 
Published: April 2003

AbstractThe effect of pH, temperature, dye concentration, and additives on the absorption of the dyes FD & C (Food, Drugs and Cosmetics) Blue 1 and Blue 2 upon poly(ethylene terephalate) (PET) and poly(butylene terephthalate) (PBT) subjected to different draw ratios (and, thus, resulting in different percentage crystallinities determined with DSC and wide‐angle X‐ray diffraction patterns) was investigated and a correlation between these parameters and the dye uptake was suggested. The absorption kinetics of the dyes on the polyesters were studied and a mechanism based upon the development of hydrogen bonds between the dyes and the end groups (COOH,OH) of the polyesters and the swelling of the network was proposed. Finally, an indirect measurement of the Tg values of the polyesters was suggested based upon the different dyeing diffusion rates. © 1994 John Wiley & Sons, Inc.
Improved methods for solving monomer partitioning in emulsion copolymer systems
Authors: Armitage Philip D. , De La Cal José C. , Asua José M. 
Published: April 2003

AbstractA new algorithm for the calculation of monomer partitioning in emulsion copolymer systems is presented. The algorithm can be applied both to monodisperse and polydisperse systems and the outputs of the algorithm include the distribution of the volume fractions of the monomers according to the particle size distribution, the volume fractions of the monomers in the monomer droplets, and the aqueous phase and the total volumes of all the phases in the system. The algorithm can handle both Interval II and Interval III conditions, using the same set of equations. This results in substantial computer time savings during the simulation of emulsion copolymerization systems. Examples of applications are given. © 1994 John Wiley & Sons, Inc.
Preparation of porous membranes grafted with poly(spiropyran‐containing methacrylate) and photocontrol of permeability
Authors: Chung Dong‐June , Ito Yoshihiro , Imanishi Yukio 
Published: April 2003

AbstractGraft copolymerization of spiropyran‐containing methacrylate (SPMMA) and acrylamide (AM) onto the surface of a porous polymer membrane was carried out. The permeability of the graft membrane varied with ultraviolet (UV) ‐ or visible‐light irradiation. It was found that the change by UV‐light irradiation of the permeability of the H2O/CH3OH mixture through the SPMMA/AM‐grafted membrane is related to the change by UV‐light irradiation of the solubility, i.e., the chain extension, of the graft copolymer in the mixed solvent. When the free SPMMA/AM copolymer becomes insoluble in the H2O/CH3OH mixture by UV‐light irradiation, the permeability of the H2O/CH3OH mixture through the SPMMA/AM‐grafted membrane is increased. © 1994 John Wiley & Sons, Inc.
Various properties of diimide–diacid‐modified saturated polysters
Authors: Lee Wen‐Fu , Chen Ienwhei , Chang Chi‐Hong 
Published: April 2003

AbstractPolyesterdiimide prepolymers containing synthesized diimide–diacid monomer (DIDAn) were synthesized under conditions previously under conditions previously reported. One‐component varnishes were obtained by mixing the synthesized prepolymers with phenol‐blocked toluene diisocyanate (TDI) and/or hexamethylene diisocyanate (HMDI). The solubility parameter of diimidemodified polyester prepolymer was investigated using an intrinsic viscosity measurement. Thermal behavior and pyrolysis activation energy were also investigated using thermogravimetric analysis. The thermal stability increased with an increase in the content of DIDA. The diimide‐modified polyester one‐component varnishes coated onto an aluminum panel were found to be acceptable, according to the specification of ASTM D‐3794. © 1994 John Wiley & Sons, Inc.
On the compatibilization and dynamic vulcanization of polyacetal/ethylene propylene diene terpolymer blends
Authors: Kumar G. , Neelakantan N. R. , Subramanian N. 
Published: April 2003

AbstractThis study describes an attempt to improve the impact resistance of polyacetal (POM)/ethylene propylene diene terpolymer (EPDM) blends by means of compatibilization and dynamic vulcanization. A commerical copolymer, poly(acrylic acid)‐grafted polypropylene (PGP), has been used as a compatibilizer to control the phase morphology of the blend system. Dicumyl peroxide is used to dynamically vulcanize the EPDM elastomer in the blend. At temperatures higher than 185°C, the compatibilizer decreases the viscosity of compatibilized and dynamically vulcanized (cdv) POM/EPDM blends. Impact strength of the cdv blend system increases considerably with a marginal decrease in tensile yield stress and heat deflection temperature as the PGP content increases. The significant increase in impact strength seems to be due to the role of PGP as a linking agent for the binary blends rather than as a third component. Though dynamic mechanical studies do not indicate any compatibility in cdv‐POM/EPDM blends, scanning electron microscopy reveals the strong interpenetrating interphase in the compatibilized blend system. Dynamic vulcanization raises elastic recovery and tensile modulus of the blends. Hysteresis energies of the blends increase consistently with the addition of PGP. The crystalline structure of POM is not affected by compatibilization and vulcanization. © 1994 John Wiley & Sons, Inc.
Properties of a mechanically processed polymeric material
Authors: Pan J. , Shaw W. J. D. 
Published: April 2003

AbstractA semicrystalline polymer, polyamide, was processed using a new technique. The technique is that of mechanically grinding the material using large inputs of energy at temperatures below the glass‐transition temperature and then later reconstituting the material by applying pressure and holding at a temperature below its melting point for a period of time. This technique is normally known as mechanical alloying and only very recently has been applied to polymeric materials. The mechanical properties of strength, ductility, toughness, and hardness of polyamide material processed by this technique are investigated and compared with those of polyamide material processed by other techniques. The results indicate that altered mechanical properties occur with specific enhancements. This means that useful structural components can be made from polymers using this processing technique. The analysis of x‐ray diffraction, nuclear magnetic resonace, scanning electron and optical microscopy suggests that this process has resulted in considerable alteration of both crystal structure and microstructure of this polymeric material. © 1994 John Wiley & Sons, Inc.
Analysis of polyethylene surface sulfonation
Authors: Fischer Dahlia , Eysel Hans H. 
Published: April 2003

AbstractAttachment of SO3H groups onto the surface of polymers by treatment with fuming sulfuric acid is a well‐known procedure. In the present study we compare the number of SO3H groups per unit area measured by a number of methods including weight gain, thickness, FT‐IR transmittance spectra, FT‐IR surface spectra with ATR method, sodium exchange, and pH measurement of water in contact with the polymer surface. It can be shown that, under the chosen conditions, i.e., room temperature and 32% SO3 in H2SO4, oxidation of PE is the main reaction, while sulfonation accounts for less than 20% of the weight gained during reaction. Differences in the reactivity of high density and low density polyethylenes are discussed. Deprotonation in water compared with H+ /Na+ exchange indicates a poor penetration of sodium ions into deeper layers of the polymer. © 1994 John Wiley & Sons, Inc.
Viscoelastic behavior of flexible slabstock polyurethane foams: Dependence on temperature and relative humidity. I. Tensile and compression stress (load) relaxation
Authors: Moreland J. C. , Wilkes G. L. , Turner R. B. 
Published: April 2003

AbstractThe relaxation behavior of the load in compression and the stress in tension was monitored at constant temperature and/or relatively humidity for a set of four slabstock foams with varying hard‐segment content as well as two of the compression molded plaques of these foams. The majority of the compression relaxation tests were done at a 65% strain level in order to be consistent with the common ILD test. The tensile stress relaxation tests were performed at a 25% strain level. Over the 3‐h testing period, a linear relationship between the log of compressive load or the log of tensile stress versus log time is observed for most testing conditions. For linear behavior, the values of the slope or the load/stress decay rate are comparable in both the tension and compression modes with the values being slightly higher in magnitude for the compression mode. These rates of decay are in the range of −2.2 × 10 −2 to −1.7 × 10 −2 for a 21 wt % hard‐segment foam and −3.2 × 10−2 to −2.4 × 10−2 for a 34 wt % hard‐segment foam. Increasing %RH at a given temperature does bring about a steady decrease in the initial load or initial stress as well as a slight increase in the rate of relaxation. The effect of temperature on the relaxation behavior is most significant at temperatures near 125°C and above. The FTIR thermal analysis of the plaques indicates that this significant increase is due to additional hydrogen bond disruption and possible chain scission taking place in the urea and urethane linkages that are principally present in the hard segment regions. The relaxation behavior in both tension and compression is believed to be mostly independent of the cellular texture of the foam at the strain levels given above. This conclusion is based on the similar relaxation behavior between the plaques and the foams. © 1994 John Wiley & Sons, Inc.
Viscoelastic behavior of flexible slabstock polyurethane foam as a function of temperature and relative humidity. II. Compressive creep behavior
Authors: Moreland J. C. , Wilkes G. L. , Turner Robert B. 
Published: April 2003

AbstractThe compression creep behavior was monitored at constant temperature and/or relative humidity for two slabstock foams with different hard‐segment content. The tests were performed by applying a constant load (free falling weight) and then monitoring the strain as a function of time over a 3‐h time period. A near linear relationship is obtained for linear strain versus log time after a short induction period for both foams and at most conditions studied (except at temperatures near and above 125°C). The slope of this relationship or the initial creep rate is dependent on the initial strain level, espcially in the range of 10–60% deformation. This dependence is believed to be related to the cellular structs buckling within this range of strain. At deformations greater than 60% and less than 10%, the solid portion of the foam is thought to control the compressive creep behavior in contrast to the cellular texture. Increasing relative humidity does cause a greater amount of creep to occur and is believed to be a result of water acting as a plasticizer. For low humidities increasing the temperature from 30 to 85°C, a decrease in the rate of creep is observed at a 65% initial deformation. At 125°C, an increase in the creep rate is seen and is believed to be related to chemical as well as additional structural changes taking place in the solid portion of the foams. The creep rate is higher for the higher hard‐segment foam (34 wt %) than that of the lower (21 wt %) at all of the conditions studied and for the same initial deformation level. This difference is principally attributed to the greater amount of hydrogen bonds available for disruption in the higher hard‐segment foam. © 1994 John Wiley & Sons, Inc.
Synthesis and fungicidal activities of polymeric biocides. I. TBZ‐containing monomer and polymers
Authors: Oh Sang Taek , Min Byung Kwon , Ha Chang Sik , Cho Won Jei 
Published: April 2003

AbstractThe fungicidal monomer, N‐acryloyl‐2‐(4′‐thiazolyl) benzimidazole (AcTBZ) was synthesized from 2‐(4′‐thiazolyl) benzimidazole (TBZ) and acryloyl chloride in the presence of triethylamine in dry benzene at 30°C. The synthesized AcTBZ was identified by IR and 1H‐NMR spectra. The homopolymers of AcTBZ were obtained using BPO as a thermal initiator in benzene under different experimental conditions such as various initiator concentrations or polymerization temperatures. The homopolymer of AcTBZ was also prepared using benzophenone as a photo initiator in DMF at 20°C. The average molecular weights (Mw) of those poly(AcTBZ) s obtained were very low, being in the order of ca. 103. Copolymer of AcTBZ and polymer of AcTBZ and acrylic acid (AA) was synthesized with thermal or photo initiators. Poly(AcTBZ) and poly(AcTBZ‐co‐AA) were identified by IR and 1H‐NMR spectra. The fungicidal activities of AcTBZ, poly(AcTBZ), and its polymers as well as TBZ against Aspergillus niger and Chaetomium globusum were very excellent compared to those of control polymers such as poly(AA) and poly(ethylene‐co‐vinyl acetate). The fungicidal activities were decreased in the order TBZ > AcTBZ > poly(AcTBZ) > poly(AcTBZ‐co‐AA) against both Aspergillus niger and Chaetomium globusum. The fungicidal activities of TBZ, and the synthesized AcTBZ and polymers containing AcTBZ were better against Chaetomium globusum than against Aspergillus niger. © 1994 John Wiley & Sons, Inc.
Properties of blends of starch and synthetic polymers containing anhydride groups
Authors: Vaidya Utpal R. , Bhattacharya Mrinal 
Published: April 2003

AbstractCorn starch was blended with styrene maleic anhydride copolymer (SMA), ethylene‐propylene‐g‐maleic anhydride copolymer (EPMA), and corresponding nonfunctional polystyrene and ethylene propylene copolymers. The concentration of starch in the blend was varied between 50 and 80% by weight. The torque generated during blending is reported increasing starch content for starch/SMA blends: the reverse was true for starch/EPMA blends. The torque was higher for the blends of the anhydride functional polymers compared to the blends of corresponding nonfunctional polymers. Water absorption of the blends increased with an increase in the starch content. Starch/SMA blends made at higher mixer speed or time were more water sensitive. Blends containing EPMA absorbed less water than SMA blends containing the same weight fraction of starch. Tensile strengths of blends containing functional groups were superior compared to the blends made from nonfunctional polymers. When the starch contents increased from 60 to 70%, the tensile strength remained unchanged for SMA blend but increased for EPMA blend. All samples supported the growth of microorganisms, which increased with increasing starch content. © 1994 John Wiley & Sons, Inc.
Semiempirical models for steady‐shear viscosity and prediction of first normal stress function
Authors: Seo Yongsok 
Published: April 2003

AbstractIn order to describe viscosity function behavior dependent on shear rate in steady‐shear flow and to predict the first normal stress function without using discrete relaxation time specturm, we combined the microscopic entanglement concept based on Graessley's entanglement network theory with the macroscopic constitutive model. The viscosity function derived from the entanglement model has three adjustable parameters and it was assumed to have the form of the inverse contangent function of the shear rate. Then the first normal stress function is obtained using the Wagner's relationship. The model prediction for the first normal stress coefficient is compared with experimental data of polymer melts. Even though viscosity function and the first normal stress function vary over a wide range of shear rate, they were in good agreement for polymer melts at high shear rate. First normal stress function do not show any numerical artifacts. However, discrepancy in the first normal stress function occurs at low shear rate. This is due to the irreversibility of the entangled molecule's motion that was not taken into consideration in the entanglement model. Irreversible nonaffine motion is introduced by adding a term similar to the White‐Metzner model's irreversible factor. Addition of irreversibility in the calculation of the first normal stress function considerably improves the agreement. Other comparisons are also presented and related discussions are given. © 1994 John Wiley & Sons, Inc.
Epoxy resin–polyethersulphone blends
Authors: Akay M. , Cracknell J. G. 
Published: April 2003

AbstractA series of amine‐cured epoxy resin systems and the blends of these containing up to 50% polyethersulphone (PES) were evaluated in terms of curing behavior, microstructure, and mechanical and dynamic mechanical thermal properties. The epoxy networks were based on a 2 : 1 mixture of triglycidyl‐p‐aminophenol and the polyglycidylether of a phenolformaldehyde novolac, and a curing agent of 3,3'‐diaminodiphenylsulphone (DDS). The curing mechanism and the rate of curing were affected by the DDS and PES contents. Reaction between the epoxy resin and hydroxyl groups attached to PES was indicated in epoxy‐rich formulations. Phase separation, evident in all the blends, was affected by the curing rate. Various blend morphologies were observed depending on the epoxy network/thermoplastic composition. Blending improved ductility and toughness‐related properties, particularly at 20–40% PES contents, which corresponded to spinodal/co‐continuous morphologies. Changes in glass transition behavior were attributed to possible variations in intermolecular free volume. © 1994 John Wiley & Sons, Inc.