bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allyl ether‐modified unsaturated polyesters for UV/air dual‐curable coatings. II: UV and air‐curing behavior
Authors: Yuan Huiya , Lu Xueyi , Zeng Zhaohua , Yang Jianwen , Chen Yonglie 
Published: March 2004

AbstractThe photoinduced and peroxide‐induced polymerization behavior of dual‐curable allyl ether‐modified unsaturated polyester (AUPE) and vinyl ether (VE) used as a reactive diluent for dual‐curable coating have been studied by infrared spectroscopy (IR). For UV curing systems in N2 atmosphere, the maleate's conversion and total conversion decrease with the increasing of allyloxy content. However, the rate and of copolymerization and conversion of VE are independent of allyloxy concentration. The copolymerization of allyl ether (AE) and vinyl ether occurs in the presence of maleate (MA) under UV irradiation. For air curing, the rate of copolymerization increases with allyloxy content. The ultimate conversion is the same irrespective of the allyloxy concentration. Because the electron‐rich double bond of allyloxy would become an electron‐deficient one through oxidation, the conversion of maleate decreases with increasing of the allyloxy content due to the enhancement of copolymerization of AE with VE. The ATR‐IR showed that different curing mechanisms occur in AUPE/VE system during air‐curing process. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2771–2776, 2004
Synthesis and properties of photoluminescent copolymer containing 1,3,4‐oxadiazole and carbazole rings
Authors: Chen Zhaobin , Liu Yufang , Zhang Caihong , Bai Fenglian 
Published: March 2004

AbstractThe luminescent copolymer 2‐phenyl‐5‐[3′‐(methacrylamido)phenyl]‐1,3,4‐oxadiazole and vinylcarbazole (PMAPO–VCZ), combining hole‐facilitating moiety, carbazole ring, and electron‐facilitating moiety, 1,3,4‐oxadiazole, as side groups, was synthesized by a radical polymerization of the olefinic monomer PMAPO and VCZ. For comparison, the homopolymer P‐PMAPO was also synthesized by similar procedures. The solubility, thermal, and optical properties of the copolymers were investigated. The synthesized copolymer was soluble in common organic solvents but the homopolymer of PMAPO was dissolved only by hot THF. Thermogravimetric analysis and differential scanning calorimetry measurements showed that the copolymer and homopolymer exhibit good thermal stability up to 360 and 340°C with glass‐transition temperatures higher than 105 and 65°C, respectively. The photoluminescence properties were investigated. The results showed that the copolymer emits blue and blue‐green light and the emission spectra of monomer and polymers exhibit obvious solvent effect. With the increase of polarity of solvents, the fluorescence spectra distinctly change, appearing with a red shift at room temperature. The concentration‐dependent emission spectra change significantly with the increase of concentration. In addition, when N,N‐dimethylaniline (DMA) was gradually added to the solution of copolymers, the emission intensity of fluorescence was dramatically increased. However, when the concentration of DMA was increased beyond a certain level, the emission intensity of fluorescence gradually decreased. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2777–2783, 2004
Dynamic mechanical analysis of poly(trimethylene terephthalate)—A comparison with poly(ethylene terephthalate) and poly(ethylene naphthalate)
Authors: Mackintosh Allan R. , Liggat John J. 
Published: March 2004

AbstractThe fiber properties of PTT have been the subject of several reports, although very few reports describe the properties of molded specimens. In this work, the dynamic mechanical relaxation behavior of compression‐molded PTT films has been investigated. The added flexibility of the PTT was found to lower the temperature of the β‐ and α‐transitions relative to the PET and PEN. The results suggest that the β‐transition is at least two relaxations for PET and PTT due to the increase in the breadth of the relaxation. The results seem to support the hypothesized mechanism of others, in that the β‐transition involves the relaxation of the carbonyl entity and the aromatic C1–C4 ring flips for PTT and PET, and the relaxation of the carbonyl for PEN. The β*‐ and α‐transitions for all three polymers seem to be cooperative in nature. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2791–2796, 2004
Phase behavior of ternary polymer blends with hydrogen bonding
Authors: Hsu Wen‐Ping 
Published: March 2004

AbstractAtactic poly (methyl methacrylate) (aPMMA) was found to be almost completely immiscible with poly(vinyl acetate) (PVAc). Both aPMMA and PVAc are known to be miscible with poly(vinyl phenol) (PVPh) according to literature. Adding of PVPh into immiscible aPMMA/PVAc mixtures is likely to improve their miscibility. Therefore, PVPh can be used as cosolvent to cosolubilize aPMMA and PVAc. A ternary blend consisting of aPMMA, PVAc, and PVPh was prepared and determined calorimetrically in this article. According to the calorimetry data, the ternary blend was determined to be miscible. The reason for the observed miscibility is because the interactions between PVAc and PVPh are similar to those between aPMMA and PVPh. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2797–2802, 2004
Antioxidant presence in thick‐walled high‐density polyethylene materials after rotational molding
Authors: Weick Brian L. , Al‐Zubi Raed S. 
Published: March 2004

AbstractHigh‐density polyethylene (HDPE) sample tanks manufactured by using a rotational molding process were used in a study to determine the presence and characteristics of antioxidants at the inside and outside surfaces of the tanks. The sample tanks were manufactured by using three different processing times to create undercooked, ideal, and overcooked tanks. Differential scanning calorimetry (DSC) was used to perform oxidation induction time (OIT) studies by using specimens cut from the surfaces of the tank. The OIT portion of the analysis exposes the melted HDPE specimens to an oxygen environment at 200°C for over 2 h. The DSC monitors change in the energy transfer rate to or from the specimen because of chemical reactions. A numerical integration process was used to analyze the DSC‐OIT data and to obtain additional information about the energy levels measured during the analysis. Fourier transform infrared (FTIR) studies were also performed to determine the chemical characteristics of specimens cut from the processed tanks. Results showed increased degradation at the inside surfaces of the overcooked tanks because of a lack of antioxidants. The results also showed that metal ions from the mold wall could react with the outside surfaces of the tanks and influence the level of antioxidants at that surface. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3052–3066, 2004
Preparation and characterization of titanium dioxide core/polymer shell hybrid composite particles prepared by emulsion polymerization
Authors: Yu Dong‐Guk , An Jeong Ho , Bae Jin Young , Lee Yong Eui , Ahn Seong Deok , Kang Seung‐Youl , Suh Kyung Soo 
Published: March 2004

AbstractTitanium dioxide inorganic core and polymer shell composite poly(methyl methacrylate‐co‐butylacrylate‐co‐methacrylic acid) [P(MMA‐co‐BA)‐MAA] particles were prepared by emulsion copolymerization. Fourier transform IR (FTIR) spectroscopy was used to measure the content of MAA composite particles. Dynamic light scattering (DLS) characterized the composite particle size and size distribution. The field emission SEM (FE‐SEM) results of the composite particles showed regular spherical shape and no bare TiO2 was detected on the whole surface of the samples. The composite particles were produced, showing good spectral reflectance compared with bare TiO2. TGA results indicated the encapsulation efficiency and estimated density of composite particles. Encapsulation efficiency was up to 78.9% and the density ranged from 1.76 to 1.94 g/cm3. Estimated density of the composite particles is suitable to 1.73 g/cm3, due to density matching with suspending media. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2970–2975, 2004
A kinetic study on the autocatalytic cure reaction of a cyanate ester resin
Authors: Chen Ching‐Chung , Don Trong‐Ming , Lin Tai‐Hung , Cheng Liao‐Ping 
Published: March 2004

AbstractThe cure of a novolac‐type cyanate ester monomer, which reacts to form a polycyanurate network, was investigated by using differential scanning calorimeter. The conversions and the rates of cure were determined from the exothermic curves at several isothermal temperatures (513–553 K). The experimental data, showing an autocatalytic behavior, conforms to the kinetic model proposed by Kamal, which includes two reaction orders, m and n, and two rate constants, k1 and k2. These kinetic parameters for each curing temperature were obtained by using Kenny's graphic‐analytical technique. The overall reaction order was about 1.99 (m = 0.99, n = 1.0) and the activation energies for the rate constants, k1 and k2, were 80.9 and 82.3 kJ/mol, respectively. The results show that the autocatalytic model predicted the curing kinetics very well at high curing temperatures. However, at low curing temperatures, deviation from experimental data was observed after gelation occurred. The kinetic model was, therefore, modified to predict the cure kinetics over the whole range of conversion. After modification, the overall reaction order slightly decreased to be 1.94 (m = 0.95, n = 0.99), and the activation energies for the rate constants, k1 and k2, were found to be 86.4 and 80.2 kJ/mol. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3067–3079, 2004
Zone drawing and zone annealing of poly(ethylene terephthalate) microfiber prepared by CO2 laser thinning
Authors: Suzuki Akihiro , Okano Takahiro 
Published: March 2004

AbstractA zone‐drawing and zone‐annealing method was applied to a poly(ethylene terephthalate) microfiber, obtained by using CO2 laser thinning, to develop its mechanical properties. The microfiber used for the zone drawing and zone annealing was prepared by winding at 1386 m/min the microfiber obtained by irradiating the laser at 18.1 W/cm2 and had a diameter of 2.8 μm and a birefringence of 0.097. Zone drawing was carried out at a drawing temperature of 105°C under an applied tension of 53 MPa, and zone annealing at an annealing temperature of 155°C under 195 MPa applied tension. Zone drawing and zone annealing were carried out at a treatment speed of 0.21 m/min. The diameter of the microfiber decreased, and its birefringence increased, with zone drawing and zone annealing. The zone‐annealed microfiber finally obtained had a diameter of 2 μm, a birefringence of 0.234, a tensile modulus of 17.9 GPa, and a tensile strength of 1.1 GPa. The wide‐angle X‐ray diffraction photograph of the zone‐annealed microfiber showed the existence of highly oriented crystallites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2989–2994, 2004
Radiation synthesis and environmental responsiveness of semi‐interpenetrating polymer networks composed of poly(dimethyl–aminoethyl methacrylate) and poly(ethylene oxide)
Authors: Liu Zhugen , Yi Min , Zhai Maolin , Ha Hongfei , Luo Zhifu , Xiang Xueqing 
Published: March 2004

AbstractSemi‐interpenetrating polymer networks (semi‐IPNs) composed of poly(dimethyl–aminoethyl methacrylate) (PDMAEMA) and poly(ethylene oxide) (PEO) were synthesized by γ‐radiation; three semi‐IPNs with 80 : 20, 90 : 10, and 95 : 5 weight ratios of DMAEMA/PEO were obtained by use of this technique. The gel–dose curves showed that the hydrogels were characterized by a structure typical of semi‐IPNs and the results of elemental analysis supported this point. The temperature‐induced phase transition of semi‐IPNs with the composition of 95 : 5 was still retained, with the lower critical solution temperature of PDMAEMA shifting from 40 to 27°C. The temperature sensitivity of the other two semi‐IPNs gradually disappeared. The pH sensitivity of three semi‐IPNs was still retained but the pH shifted slightly to lower values with increasing PEO content in the semi‐IPNs. The effect of PEO content in semi‐IPNs on their environmental responsiveness was discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2995–3001, 2004
Water vapor permeability and mechanical properties of fabrics coated with shape‐memory polyurethane
Authors: Cho Jae Whan , Jung Yong Chae , Chun Byoung Chul , Chung Yong‐Chan 
Published: March 2004

AbstractWater vapor permeable fabrics were prepared by coating shape‐memory polyurethane (PU), which was synthesized from poly(tetramethylene glycol), 4,4′‐methylene bis(phenylisocyanate), and 1,4‐butanediol, onto polyester woven fabrics. Water vapor permeability and mechanical properties were investigated as a function of PU hard‐segment content or polymer concentration of the coating solution. Water vapor permeability of PU‐coated fabrics decreased dramatically with increased concentration of coating solution, whereas only a slight change was observed with the control of PU hard‐segment content. The coated fabric showed the clear appearance of a nonporous PU surface according to SEM measurements. Attainment of high water permeability in PU‐coated fabrics is considered to arise from the smart permeability characteristics of PU. Mechanical properties of coated fabrics, although there was some variation depending on the concentration of coating solution, were primarily affected by PU hard‐segment content. Fabrics coated with PU hard‐segment content of 40% showed the lowest breaking stress and modulus as well as the highest breaking elongation, which could be interpreted in terms of the dependency of mechanical properties of coated fabrics on PU hard‐segment content and the yarn mobility arising from a difference in penetrating degree of coating solution into the fabric. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2812–2816, 2004
Modified emulsifier‐free emulsion polymerization of butyl methacrylate with ionic or/and nonionic comonomers
Authors: Xu Xiao‐Jun , Chen Fengxi 
Published: March 2004

AbstractA modified emulsifier‐free emulsion polymerization of butyl methacrylate (BMA) with ionic or/and nonionic comonomers was successfully used to prepare nanosized poly(butyl methacrylate) (PBMA) latices with high polymer contents. After seeding particles were generated in an initial emulsion system, consisting of a portion of BMA, water, ionic comonomer [sodium styrenesulfonate (NaSS)] or nonionic comonomer [2‐hydroxyethyl methacrylate (HEMA)] and potassium persulfate, most of the BMA monomer or the mixture of BMA and HEMA was added dropwise to the polymerizing emulsion over a period of 6–12 h. Stable latices with high PBMA contents up to 27% were obtained. It was found that the latex particle sizes (2Rh) were largely reduced (34 nm) by the continuous addition of monomer(s) compared to those (107 nm) obtained by the batch polymerization method. The effect of comonomer concentration on the particle size, the number of PBMA particles/mL of latex (Nd), and the molar mass (Mw) of copolymer during the polymerization were discussed. The surface compositions of latex particles were analyzed by X‐ray photoelectron spectroscopy, indicating that the surface of latex particles was significantly enriched in NaSS or/and HEMA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3080–3087, 2004
Studying the mechanisms of titanium dioxide as ultraviolet‐blocking additive for films and fabrics by an improved scheme
Authors: Yang Hongying , Zhu Sukang , Pan Ning 
Published: March 2004

AbstractTitanium dioxide (TiO2) has good ultraviolet (UV)‐blocking power and is very attractive in practical applications because of such advantages as nontoxicity, chemical stability at high temperature, and permanent stability under UV exposure, for example. Development of nanoscience and ‐technology provides new ways for better treatment for UV‐resistant films and fabrics using TiO2. However, the exact mechanisms of TiO2 as a UV‐blocking additive are still not very clear, and researchers hold different views on this issue. The aim of this investigation was to study systematically the mechanisms of TiO2 as a UV‐blocking additive for films and fabrics. To achieve this goal, the conventional scheme describing light interactions with fabrics was revised based on more recent progress in optical theory, and special experiments and analytic methods were used in the investigation. Several effects attributed to the nanoscale additives were identified. Moreover, detailed analyses based on the results yielded a few important suggestions useful in developing or improving both inorganic UV‐blocking agents and the UV‐protective films and textiles. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3201–3210, 2004
Effects of solvent adsorption on solution properties of poly(vinyl alcohol)/dimethylsulfoxide/water ternary systems
Authors: Hong Shi‐Jie , Huang Hsing‐Tsai , Hong Po‐Da 
Published: March 2004

AbstractIn this study, the solvent adsorption phenomena of poly(vinyl alcohol) (PVA) in cosolvent mixtures of dimethylsulfoxide (DMSO; solvent 1) and water (solvent 2) were investigated. Typically, this cosolvent mixture could form hydrogen‐bonded DMSO/(water)2 complexes, involving one DMSO and two water molecules. Because of the complex formation in the cosolvent mixtures, PVA chains preferentially adsorb water molecules at DMSO mole fraction X1 < 0.33, but preferentially adsorb DMSO molecules at X1 > 0.33. The preferential adsorption of DMSO (a good solvent for PVA) could cause the relatively extended conformation of PVA chains in solutions because of the increase in excluded volume effect. Because of various interactions between PVA chains and cosolvent mixtures, the aggregation and gelation behaviors of PVA solutions were significantly affected by the composition of cosolvent mixture. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3211–3217, 2004
Crashworthiness of automotive composite material systems
Authors: Jacob George C. , Fellers John F. , Starbuck J. Michael , Simunovic Srdan 
Published: March 2004

AbstractThe energy absorption capability of a composite material is important in developing improved human safety in an automotive crash. In passenger vehicles, the ability to absorb impact energy and be survivable for the occupant is called the crashworthiness of the structure. The crashworthiness in terms of the specific energy absorption (SEA) of a chopped carbon fiber (CCF) composite material system was compared with that of other fiber resin systems such as graphite/epoxy cross‐ply laminates (CP#1 and CP#2), a graphite/epoxy‐braided material system (O), and a glass‐reinforced continuous‐strand mat (CSM). The quantity of these material systems needed to ensure passenger safety in a midsize car traveling at various velocities was calculated and compared. The SEA of the chopped carbon fiber composite material was the highest compared to that of all the other composites investigated. It was calculated that only 4.27 kg of it would need to be placed at specific places in the car to ensure passenger safety in the event of a crash at 15.5 m/s (35 mph). This clearly led to an important practical conclusion that only a reasonable amount of this composite material is required to meet the necessary impact performance standard. The CCF composite tested at 5 mm/min crushing speed met both the criteria that need to be satisfied before a material is deemed highly crashworthy: A high magnitude of energy absorption and a safe allowable rate of this energy absorption. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3218–3225, 2004
Determination of the saturation adsorption of surfactant in polymer latices
Authors: Roose P. , De Doncker P. 
Published: March 2004

AbstractThe volumetric determination of the surfactant adsorption density at maximum packing (saturation) is studied in binary latex blends. A phenomenological description for latex mixtures that are not free of surfactant prior to titration predicts a quadratic dependence for the saturation adsorption density as a function of the fractional surface area of the latex compounds. The expected behavior was verified experimentally from conductometric titrations of sodium dodecyl sulfate in blends of homopolymer latices cleaned with the serum replacement technique. Accordingly, it is shown that surfactant titration of binary latex blends provides indications about the level of cleaning of the mixed compounds. Furthermore, when latex mixtures are prepared by using a surfactant‐free reference latex, this approach may be used for the estimation of the saturation adsorption area of the bare polymer surface for an incompletely cleaned latex. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3226–3230, 2004
Biodegradable soy protein–polyester blends by reactive extrusion process
Authors: Graiver D. , Waikul L. H. , Berger C. , Narayan R. 
Published: March 2004

AbstractBlends of soy protein concentrate and biodegradable polyester (Eastar Bio Copolyester, EPE) were prepared by using glycerol as a compatibilizing agent. Good miscibility was obtained only when the soy protein was initially combined with glycerol under high shear and at elevated temperatures in an extruder. Under these conditions, partial denaturing of the soy protein led to specific interactions between functional groups of the protein with the glycerol. The extrusion conditions and appropriate screw configuration were the critical factors affecting the reactivity of the protein and hence, the properties of the blends. Screws with large kneading blocks that produced high shear mixing were preferred and led to thermoplastic blends characterized by high elongation and high tensile strength. The morphology of these soy protein/polyester blends was studied by using environmental scanning electron microscopy (ESEM) and indicated good wetting of the soy protein particles within the polyester matrix. The thermal properties were studied by differential scanning calorimetry (DSC) and showed a lower degree of crystallinity and a continuous depression of the melting point of the polyester as the concentration of protein was increased. The possibility of using soy protein concentrate instead of the more expensive (higher purity) soy protein isolate in the preparation of biodegradable resins should lead to new commercial opportunities based on renewable, agricultural byproducts. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3231–3239, 2004
Memory effects in supramolecular networks of diacids and polyfunctional pyridine derivatives
Authors: Wiegel Kurt N. , Griffin Anselm C. , Black Micah S. , Schiraldi David A. 
Published: March 2004

AbstractHighly crosslinked networks were produced through a series of diacids and tetrakis pyridyls. These materials displayed complex crystallization behaviors over multiple heat/cool cycles. The shifting of crystallization behaviors with time in the melt phase seems to indicate that the materials move toward thermodynamically ideal structures. This behavior is suggestive of a type of memory in which the networks remember the morphological structure previous to the melt and improve upon that structure in the next cooling cycle. The network/memory phenomena observed in small molecule diacid/tetrapyridyl systems also appeared to exist when poly(ethylene terephthalate) (PET) polymer was used as the source of carboxylic acid functionalities. The same time‐ dependent behaviors, suggestive of sequential steps toward thermodynamically optimum states, were observed when the PET/tetrapyridyl systems were thermally cycled. It was also observed that complexation of tetrapyridyl with PET brought about a significant change in oxygen gas barrier properties; these changes were opposite to those obtained when covalent crosslinks were introduced into PET. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3097–3106, 2004