bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of unsaturated polyester resin from postconsumer PET bottles: Effect of type of glycol on characteristics of unsaturated polyester resin
Authors: Pimpan V. , Sirisook R. , Chuayjuljit S. 
Published: February 2003

AbstractPostconsumer PET bottles including water and soft‐drink bottles were depolymerized by glycolysis in excess glycols, such as ethylene glycol, propylene glycol, and diethylene glycol, in the presence of a zinc acetate catalyst. The obtained glycolyzed products were reacted with maleic anhydride and mixed with a styrene monomer to prepare unsaturated polyester (UPE) resins. These resins were cured using methyl ethyl ketone peroxide (MEKPO) as an initiator and cobalt octoate as an accelerator. The physical and mechanical properties of the cured samples were investigated. It was found that the type of glycol used in glycolysis had a significant effect on the characteristics of the uncured and cured UPE resins. Uncured EG‐based UPE resin was a soft solid at room temperature, whereas uncured PG‐ and DEG‐based resins were viscous liquids. In the case of the cured resins, the EG‐based product exhibited characteristics of a hard and brittle plastic, while the PG‐based product did not. The DEG‐based product exhibited characteristics of hard and brittle plastic after strain‐induced crystallization had occurred. In addition, it was also found that no separation of the type of bottles was needed before glycolysis, since UPE resins prepared from water bottles, soft‐drink bottles, and a mixture of both bottles showed the same characteristics. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 788–792, 2003
Solution miscibility and phase‐change behavior of a polyethylene glycol–diacetate cellulose composite
Authors: Guo Yuanqiang , Tong Zhen , Chen Mingcai , Liang Xuehai 
Published: February 2003

AbstractPolyethylene glycol (PEG) and diacetate cellulose (CDA) exhibit good miscibility in acetone solution. The miscibility is related to the molecular weight of PEG, which increases as miscibility decreases. The phase‐change behavior of PEG in composite with CDA prepared from the miscible solution was found to be completely different from that of pure PEG. When the PEG fraction in the composites was less than 85%, PEG within the composite did not melt into liquid; even when the temperature was 40°C higher than the melting point of PEG, the PEG–CDA composite exhibited solid–solid phase‐change behavior. Thermal analysis indicated that the PEG–CDA composite had greater enthalpy and exhibited good thermal stability. The PEG–CDA composite that exhibited solid–solid phase‐change behavior can be used as a new kind of phase‐change material for thermal energy storage and temperature control. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 652–658, 2003
Compounding and injection molding of polybutene‐1/polypropylene blends
Authors: Kalay G. , Kalay C. R. 
Published: February 2003

AbstractThe effect of shear‐controlled orientation injection molding (SCORIM) was investigated for polybutene‐1/polypropylene blends. This article reports on the methods and processing conditions used for blending and injection molding. The properties of SCORIM moldings are compared with those of conventional moldings. SCORIM is based on the application of specific macroscopic shears to a solidifying melt. The multiple shear action enhances molecular alignment. The moldings were investigated with mechanical tests, differential scanning calorimetry studies, and polarized light microscopy. The application of SCORIM improved Young's modulus and the ultimate tensile strength. The gain in stiffness was greater for higher polybutene‐1 content blends. A drastic decrease in the strain at break and toughness was observed in SCORIM moldings. The enhanced molecular orientation of SCORIM moldings resulted in a featureless appearance of the morphology. Interfacial features due to segregation were visible in the micrographs of SCORIM moldings. Both conventional and SCORIM moldings exhibited form I′ in polybutene‐1. This article explains the relationship between the mechanical properties and micromorphologies. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 806–813, 2003
Thermal behavior of acrylonitrile carboxylic acid copolymers
Authors: Hajir Bahrami S. , Bajaj P. , Sen K. 
Published: February 2003

AbstractPolyacrylonitrile (PAN) and copolymer of acrylonitrile–vinyl acids prepared by solution polymerization technique have been characterized by Differential Scanning Calorimetry (DSC) (under dynamic as well as isothermal conditions), themograviemetric analysis (TGA), and on‐line DSC‐FTIR spectroscopy. The DSC of copolymers was carried out at 5°C/min in nitrogen and air. In nitrogen atmosphere the DSC exotherm show a very sharp peak, whereas, in air atmosphere DSC exotherm is broad, and starts at a much lower temperature compared to what is observed in nitrogen atmosphere. The initiation temperature of PAN homopolymer is higher than that for the copolymers. For instance, the initiation temperature of PAN in air is 244°C, whereas, the onset of exothermic reaction is in the range of 172 to 218°C for acrylonitrile–vinyl acid copolymers. As the vinyl acid content increases the ΔH value reduces. The ΔH value of PAN in air was 7025 J/g, whereas, for P(AN‐AA) with 5.51 mol % of acid it was 3798 J/g. As the content of acrylic acid comonomer is increased to 17.51 mol % the value of ΔH decreases further to 1636 J/g. The same trend was observed with MAA and IA as well. DSC‐FTIR studies depict various chemical changes taking place during heat treatment of these copolymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 685–698, 2003
Structure and physical property relationships in processed polybutene‐1
Authors: Kalay G. , Kalay C. R. 
Published: February 2003

AbstractThe effect of SCORIM was investigated on three grades of polybutene‐1 and one grade of ethylene–butene‐1 copolymer. The methods and processing conditions used for injection molding and the properties of the moldings are reported. Phase transformations and their relationship with mechanical properties are discussed in detail. Both, conventional and shear‐controlled orientation injection molding (SCORIM) were employed to produce moldings. SCORIM is based on the application of specific macroscopic shears to a solidifying melt. The multiple shear action enhances molecular alignment. The moldings were investigated by performing mechanical tests, fractographic analysis, differential scanning calorimetry studies, wide‐angle X‐ray diffraction, polarized light microscopy, and atomic force microscopy. The application of SCORIM improves the mechanical performance. Molecular orientation results in the formation of shish‐kebab morphology. One grade of polybutene‐1 exhibited a greater than fivefold increase in Young's modulus. The application of high cavity pressures favored the formation of the stable Form I' in polybutene‐1. The formation of Form I' led to a decrease in crystallinity and mechanical properties. However, this loss was by far smaller than the gain obtained via the formation of shish‐kebab morphology. The relationship between mechanical properties and micromorphologies of the investigated materials is explained. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 814–824, 2003
Surface treatments on Tencel fabric: Grafting with β‐cyclodextrin
Authors: Nostro Pierandrea Lo , Fratoni Laura , Ridi Francesca , Baglioni Piero 
Published: February 2003

AbstractTencel is a cellulosic fabric obtained from wood pulp that is very similar to natural cotton. For its potential performances to be expanded, Tencel needs to be processed in different ways. The ability of cyclodextrins to include hydrophobic molecules, such as fragrances, antimicrobial agents, and other chemicals, can be exploited to produce new grafted textiles with peculiar performances. We report studies on the grafting of acrylamidomethylated β‐cyclodextrin and monochlorotriazinyl‐β‐cyclodextrin to Tencel and on the inclusion of different molecules in the free cavities of cyclodextrins. The physicochemical properties and performances of the untreated and treated fabric have been determined with differential scanning calorimetry, ultraviolet–visible spectra, X‐ray diffractometry, and breaking load loss, aroma, and antimicrobial finishing tests. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 706–715, 2003
Biodegradation study of a coextruded starch and poly(lactic acid) material in various media
Authors: Gattin Richard , Copinet Alain , Bertrand Céline , Couturier Yves 
Published: February 2003

AbstractThe biodegradation of a coextruded starch/poly(lactic acid) polymeric material was studied in a liquid, in an inert solid, and in composting media. Mineralization of the material's carbon content was followed using the appropriate ASTM standard experimental methods. The final percentage of biodegradation depended on the nature of the medium used. The percentage of mineralization (Cg) was better with the liquid medium (65%) than with either the compost medium (64%) or the inert medium (59%). To understand the workings of the biodegradability of the polymer material, a measurement of the carbon balance seemed essential A repartitioning of the material's carbon between the various degradation products to biomass carbon (Cb), to carbon dioxide carbon (Cg), to dissolved organic carbon (Cs), and to residual insoluble material carbon (Cnd) produced was quantified throughout the experimental runs. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 825–831, 2003
Synthesis of syndiotacticity‐rich high molecular weight poly(vinyl alcohol) by suspension polymerization of vinyl pivalate and saponification
Authors: Lyoo Won Seok , Park Chan Sik , Kim Joon Ho , Ghim Han Do , Lee Ji Youl , Lee Jinwon , Lee Chul Joo 
Published: February 2003

AbstractVinyl pivalate (VPi) was suspension‐polymerized to synthesize high molecular weight (HMW) poly(vinyl pivalate) (PVPi) with a high conversion above 95% for a precursor of syndiotacticity‐rich HMW poly(vinyl alcohol) (PVA). Also, the effects of the polymerization conditions on the conversion, molecular weight, and degree of branching (DB) of PVPi and PVA prepared by the saponification of PVPi were investigated. Bulk polymerization was slightly superior to suspension polymerization in increasing the molecular weight of PVA. On the other hand, the latter was absolutely superior to the former in increasing the conversion of the polymer, indicating that the suspension polymerization rate of VPi was faster than that of the bulk one. These effects could be explained by a kinetic order of a 2,2′‐azobis(2,4‐dimethylvaleronitrile) concentration calculated by the initial rate method. Suspension polymerization of VPi at 55°C by controlling various polymerization factors proved to be successful in preparing PVA of HMW [number‐average degree of polymerization (Pn): 8200–10,500], high syndiotactic diad content (58%), and very high yield (ultimate conversion of VPi into PVPi: 94–98%). In the case of the bulk polymerization of VPi at the same conditions, the maximum Pn and conversion of 10,700–11,800 and 32–43% were obtained, respectively. The DB was lower and the Pn was higher with PVA prepared from PVPi polymerized at lower initiator concentrations. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 832–839, 2003
Study on the structure of nylon 6 films iodinated before forming. I. Comparison with the film iodinated after forming
Authors: Kang Young Ah , Lee Yang Hun 
Published: February 2003

AbstractTo examine the possibility of applying the iodination of nylon 6 to forming, a new type of nylon 6–iodine complex films iodinated before forming (IBF film) and the old type of films iodinated after forming (IAF film) were prepared and their structures were investigated and compared with each other. The IBF films from iodinated nylon 6 powders could be obtained by a melt press at 185°C, which is much lower than the melt‐press temperature of pure nylon 6 (250°C). It was ascertained that the structure of IAF films is similar to that reported by Lee et al. but the structure of IBF films is very different. The distinctive features of the IBF films compared with the IAF films are as follows: The IBF films have no excess iodine molecules (I2) to form a complex with nylon 6 chains because those molecules in the iodinated powders have been evaporated through the melt press. The IBF films have a practically amorphous structure but only a few crystalline portions with a relaxed state which may have been created with iodide‐ion‐free segments of nylon 6 molecules through the procedure of film forming. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1138–1144, 2003
Bottom design of carbonated soft drink poly(ethylene terephthalate) bottle to prevent solvent cracking
Authors: Lyu Min‐Young , Pae Youlee 
Published: February 2003

AbstractThe use of a petaloid shape for the bottom design for carbonated PET bottles is widespread. Through this study, the causes of bottom cracking were investigated and a novel petaloid bottom was designed. The variations of the physical properties of PET according to the stretch ratio were examined and the stretch ratios in the blown bottle were analyzed. Cracking phenomena of the bottom were observed by a solvent‐cracking test. The effective stress and the maximum principal stress in a carbonated bottle were analyzed by computer simulation. It was concluded that the bottom crack occurs because of not only the insufficient strength of material due to the insufficient stretch of PET but also to the coarse design of the petaloid shape. The highest maximum principal stress occurred at the valley in the petaloid bottom of the bottle and this strongly affected the cracking in the bottom. The petaloid shape was redesigned to minimize the maximum principal stress, and this resulted in increasing the crack resistance. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1145–1152, 2003
Improved methods for evaluating the molar mass distributions of cellulose in kraft pulp
Authors: Berggren Rickard , Berthold Fredrik , Sjöholm Elisabeth , Lindström Mikael 
Published: February 2003

AbstractMulti‐angle laser light scattering (MALLS) was used to characterize birch kraft pulps with respect to their absolute molecular mass distributions (MMDs). The pulps were dissolved in lithium chloride/N,N‐dimethylacetamide and separated by size exclusion chromatography (SEC). The weight‐average and number‐average molecular masses of the cellulose fractions of the pulps obtained from the absolute MALLS measurements were compared with the molar masses obtained by direct‐standard‐calibration relative pullulan standards. Discrepancies between the two detection methods were found, and two ways of correlating the relative pullulan molar masses to the absolute molar masses were examined. In the first method, the correlation was made over a large range of molecular masses. The second method correlated the molecular masses of the standards to the molecular masses of samples by the calculation of fictitious, cellulose‐equivalent molar masses of the standards. With the preferred second method, a more correct MMD of kraft pulp samples could, therefore, be obtained from an SEC system calibrated with narrow standards. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1170–1179, 2003
Preparation and property of poly(ethylene terephthalate) fibers providing ultraviolet radiation protection
Authors: Teng Cuiqing , Yu Muhuo 
Published: February 2003

AbstractInterest in protection against solar ultraviolet radiation (UVR) among the general public in the world has been increasing steadily. Poly(ethylene terephthalate) (PET) was blended with UVR‐protection agents and was spun into modified fibers to provide the property of UVR protection. Investigation of this property using a UV spectrophotometer showed that the modified PET fabrics could be resistant to UVR more than 90% in the UV‐B band. The treatment of aqueous alkali on the surface of the fibers to improve the comfortable feel had little influence on the property of UVR protection. Scanning electron microscopy was employed to observe the surface morphology of the fibers. Also, the modified fibers had good heat insulation property and the mechanical properties of the fibers were measured. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1180–1185, 2003
Process–structure–property relationship in ternary short‐glass‐fiber/elastomer/polypropylene composites
Authors: Tjong S. C. , Xu S. A. , Mai Y. W. 
Published: February 2003

AbstractShort‐glass‐fiber (SGF)‐reinforced polypropylene (PP) composites toughened with a styrene/ethylene butylene/styrene (SEBS) triblock copolymer were injection molded after extrusion. Furthermore, a maleic anhydride (MA)‐grafted SEBS copolymer (SEBS‐g‐MA) was used as an impact modifier and compatibilizer. The effects of the processing conditions and compatibilizer on the microstructure and tensile and impact performance of the hybrid composites were investigated. In the route 1 fabrication process, SGF, PP, and SEBS were blended in an extruder twice, and this was followed by injection molding. In route 2, or the sequential blending process, the elastomer and PP were mixed thoroughly before the addition of SGF. In other words, either PP and SEBS or PP and SEBS‐g‐MA pellets were premixed in an extruder. The produced pellets were then blended with SGF in the extruder, and this was followed by injection molding. The SGF/SEBS‐g‐MA/PP hybrid fabricated by the route 2 process exhibited the highest modulus, yield stress, tensile stress at break, Izod impact energy, and Charpy drop weight impact strength among the composites investigated. This was due to the formation of a homogeneous SEBS elastomeric interlayer at the SGF and matrix interface of the SGF/SEBS‐g‐MA/PP hybrid. This SEBS rubbery layer enhanced the interfacial bonding between SGF and the matrix of the SGF/SEBS‐g‐MA/PP hybrid. The correlations between the processing, microstructure, and properties of the hybrids were investigated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1384–1392, 2003
Stretchable conductive fabric for electrotherapy
Authors: Oh Kyung Wha , Park Hyun Jin , Kim Seong Hun 
Published: February 2003

AbstractChanges in conductivity with repeated fabric extension were investigated to improve the properties of conductive electrode pad material used for electrotherapy when it is subjected to various movement of human body. Highly stretchable and conductive fabrics were prepared byin situchemical polymerization of polypyrrole on nylon–spandex stretch fabric in aqueous solutions with 0.5 M pyrrole, 1.165 M FeCl3, and 0.165 M benzenesulfonic acid at 5°C for 1 h. Performance of prepared stretchable conductive fabric was evaluated in terms of conductivity changes as a function of tensile strain, repeated extension, and current application time. As the degree of extension increased, the conductivity increased and leveled off when the fabric was subjected to 60% extension. The number of fiber contacts in nylon–spandex fabric with electrode increased as the applied extension increased. However, the conductivity of the composite decreased under excessive extension over 60% since the intrinsic elasticity of fabric became gradually reduced. Generally, the fabric conductivity decreased as the number of extension cycles increased. However, the fabric conductivity was well maintained after repeated extension over 30 cycles at 40% extension. In addition, it was found that the effect of charging during the electrotherapy treatment on a current flow through prepared electrode pad was negligible. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1225–1229, 2003
Thermal and viscoelastic properties of some commercial starch products
Authors: Contat‐Rodrigo L. , Ribes‐Greus A. 
Published: February 2003

AbstractThree commercial starch products for polyolefins, marketed under the Mater‐Bi, Cornplast, and Bioefect trademarks, were subjected to an accelerated soil burial test. Their thermal and viscoelastic behaviors were studied by differential scanning calorimetry (DSC) and dynamic mechanical spectroscopy. Degradation in soil leads to more significant changes both in the DSC thermogram and the mechanical relaxation spectrum of Mater‐Bi. The relaxation spectra of Cornplast and Bioefect, two products containing polyethylene, basically coincide with that of pure low density polyethylene. The α‐relaxation zone of these starch products is the most affected by the degradation process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1242–1251, 2003
New poly(amide imide imide)s based on tetraimide dicarboxylic acid condensed from 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, m‐aminobenzoic acid, and 4,4″‐oxydianiline and various aromatic diamines
Authors: Yang Chin‐Ping , Chen Ruei‐Shin , Hsu Mao‐Feng 
Published: February 2003

AbstractA series of new, organosoluble, and light‐colored poly(amide imide imide)s were synthesized from tetraimide dicarboxylic acid (I) and various aromatic diamines by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. I was prepared by the azeotropic condensation of 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, m‐aminobenzoic acid, and 4,4′‐oxydianiline at a 2/2/1 molar ratio in N‐methyl‐2‐pyrrolidone (NMP)/toluene. The thin films cast from N,N‐dimethylacetamide (DMAc) had cutoff wavelengths shorter than 400 nm (365–394 nm) and color coordinate b* values between 13.10 and 36.07; these polymers were lighter in color than the analogous poly(amide imide)s and isomeric polymers. All of the polymers were readily soluble in a variety of organic solvents, including NMP, DMAc, N,N‐dimethylformamide, dimethyl sulfoxide, and even less polar dioxane and tetrahydrofuran. The cast films exhibited tensile strengths of 90–104 MPa, elongations at break of 7–22%, and initial moduli of 1.9–2.4 GPa. The glass‐transition temperatures of the polymers were recorded at 274–319°C. They had 10% weight losses at temperatures beyond 520°C and left more than a 50% residue even at 800°C in nitrogen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 669–679, 2003
Phase dispersion–crosslinking synergism in binary blends of poly(vinyl chloride) with low‐density polyethylene: Entrapping phenomenon in PVC/LDPE/DCP blend
Authors: Ma Guowei , Fang Zhengping , Xu Chengwei 
Published: February 2003

AbstractThe co‐crosslinked products and the entrapping phenomenon that may exist in a poly(vinyl chloride)/low density polyethylene/dicumyl peroxide (PVC/LDPE/DCP) blend were investigated. The results of selective extraction show that unextracted PVC was due to not being co‐crosslinked with LDPE but being entrapped by the networks formed by the LDPE phase. SBR, as a solid‐phase dispersant, can promote the perfection of networks of the LDPE phase when it is added to the PVC/LDPE blends together with DCP, which leads to more PVC unextracted and improvement of the mechanical properties of PVC/LDPE blends. Meanwhile, the improvement of the tensile properties is dependent mainly on the properties of the LDPE networks. Finally, the mechanism of phase dispersion–crosslinking synergism is presented. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1296–1303, 2003