bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbonaceous materials prepared from carbon tetrachloride and dimethyl sulfoxide
Authors: Wang Fan , Shi Gaoquan , Xu Zhengjiang , Zhang Jiaxin , Chen Fengen , Hong Xiaoyin 
Published: August 2002

AbstractA novel liquid/solid two‐phase reaction has been discovered that enables destruction of carbon tetrachloride (CCl4) to a black carbon‐based material. The solid phase is potassium hydroxide, and the liquid phase is a dimethyl sulfoxide (DMSO) solution of carbon tetrachloride and contains a certain amount of tetrabutylammonium bromide (TBAB) as the phase‐transfer catalyst. The reaction can be carried out at room temperature and under normal pressure. Pyrolysis of the carbon‐based materials at 700°C and under a nitrogen atmosphere resulted in the formation of amorphous carbonaceous nanoparticles with diameters in the range of 30–60 nm. The carbonaceous materials have a specific surface area of 430 m2/g and an average pore size of 16 Å. Raman spectral and elemental analysis results show the carbonaceous material consists of sp3 and sp2 carbons and also contains a small amount of hydrogen (H/C = 0.08). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 785–791, 2002
Effect of comonomers on melt processability of polyacrylonitrile
Authors: Rangarajan P. , Yang J. , Bhanu V. , Godshall D. , McGrath J. , Wilkes G. , Baird D. 
Published: August 2002

AbstractThis work is concerned with the feasibility of achieving melt‐processable polyacrylonitrile copolymer systems as precursors for the manufacture of carbon fibers. Identification of suitable comonomers and achieving the optimum content of the comonomer were some of the main objectives of this investigation. It was seen that methyl acrylate (MA) was found to be suitable for enabling the melt processing of polyacrylonitrile (PAN), in terms of melt viscosity, time stability, and char yield. Below 10 mol % of MA, the PAN copolymer exhibited no flowability, even at very low molecular weights (∼ 20,000). The long‐range order inherently present in PAN is speculated to be broken down at a critical value of about 10% MA at 220°C in the PAN‐based system, enabling its melt flowability. It was also seen that the incorporation of MA was seen to improve the temperature and molecular weight window of processability of the PAN system. The molecular weight cutoff for the 90/10 mol % acrylonitrile/methyl acrylate (AN/MA) system was about 50,000 at 220°C, whereas it was increased to about 100,000 in the presence of 15 mol % MA comonomer. Feasibility studies on the use of other comonomers such as higher acrylates and acrylamides were also conducted. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 69–83, 2002
Blends of i‐PP and SBS. I. Influence of the in situ compatibilization on the morphology
Authors: Wilhelm Helena Maria , Felisberti Maria Isabel 
Published: August 2002

AbstractThis article concerns the in situ compatibilization of immiscible isotactic polypropylene/butadiene‐styrene‐butadiene triblock copolymer blends (i‐PP/SBS) by means of a reactive mixture. For this purpose, maleated PP (PP‐MAH) and SBS (SBS‐MAH) were used as functionalized polymers and 4,4′‐diaminediphenylmethane was used as a coupling agent between maleated polymers, resulting in a graft copolymer. Binary blends i‐PP/SBS, nonreactive ternary blends i‐PP/PP‐MAH/SBS, and reactive ternary blends i‐PP/PP‐MAH/SBS‐MAH with varying diamine and anhydride molar ratios were prepared. Torque measurements suggest a graft copolymerization during the melt blending for ternary reactive blends, but the extension of the grafting does not vary with the diamine and anhydride molar ratio, but with the elastomer concentration. The morphology of the blends was investigated by scanning electron microscopy. The morphology of binary and ternary nonreactive blends is similar, exhibiting elastomer domains disperse in the i‐PP matrix, whose sizes increase with elastomer concentration. On the other hand, the elastomer domain size in the ternary reactive blends is practically independent of the blends composition and of the diamine and anhydride molar ratio. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 847–855, 2002
Recoverable shear strain of liquid crystal‐forming concentrated hydroxypropyl cellulose solutions
Authors: Suto Shinichi , Mitamura Junya , Sasaki Yasuyuki 
Published: August 2002

AbstractThe recoverable shear strain (SR) for the liquid crystal‐forming hydroxypropyl cellulose solutions was determined by means of a concentric cylinder rotational apparatus as functions of shear stress prior to recovery and concentration of the solutions at 30°C. SR greatly depended on shear stress and concentration; the phase of the solution (the single phase or biphase) governed the dependences of SR on stress and concentration. SR increased with increasing stress for the single phase and decreased for the biphase. SR seemed to be related to the die swell (B): SR ∝ Bn. SR exhibited a maximum and a minimum with respect to concentration. SR for the cellulosic cholesteric liquid crystalline solutions was greater than that for the isotropic solutions. A model was proposed for explaining the greater SR. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 865–872, 2002
Syntheses and characterization of poly(butylene terephthalate) copolyesters modified with p‐acetoxybenzoic acid
Authors: Kang Tae‐Kyu , Kim Yang , Cho Won‐Jei , Ha Chang‐Sik 
Published: August 2002

AbstractPoly(butylene terephthalate) (PBT) copolyesters modified with seven compositions of p‐acetoxybenzoic acid (PABA) ranging from 10 to 70 mol % were prepared. The X‐ray diffraction patterns, the polarizing microscopy behaviors, and thermal analysis showed that the modified PBT contained more PABA homopolymer units (PABA–PABA) than PBT–PABA units in the copolyesters. On increasing PABA mole percenage, PBT crystallinity decreased and thermal stability increased. It was found that although the PBT copolyesters did not exhibit a clear liquid crystalline texture like the copolyester of poly(ethylene terephthalate) modified with PABA did, the PBT copolyester containing 70 mol % of PABA exhibited the typical shear thinning behavior of a liquid crystalline polymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1085–1095, 2001
Synthesis of new polyureas derived from 4‐cyclohexylurazole
Authors: Mallakpour Shadpour E. , Rostamizadeh Hossein 
Published: August 2002

Abstract4‐Cyclohexylurazole (1) R = cyclohexyl (CHU) was prepared from cyclohexyl isocyanate in two steps. Polycondensation reactions of compound CHU with hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), and toluene‐2,4‐diisocyanate (TDI) were performed in DMAc/chloroform and DMAC in the presence of pyridine as a catalyst. The resulting novel polyureas have an inherent viscosity in the range of 0.044–0.206 g/dL in DMF at 25°C. These polyureas were characterized by IR, 1H–NMR, elemental analysis, and TGA. The resulting polymers are soluble in most organic solvents. Some physical properties and structural characterization of these novel polyureas are reported. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1335–1341, 2001
Conducting composite film based on polypyrrole and crosslinked cellulose
Authors: Yin Wusheng , Li Jun , Li Yongming , Wu Jingpin , Gu Tiren 
Published: August 2002

AbstractPolypyrrole/crosslinked cellulose conductive composite films were prepared by vapor‐phase polymerization of pyrrole on the silicon crosslinked cellulose network using anhydrous ferric chloride as oxidant. The properties of the composite film depend on their synthetic conditions such as the amount of ferric chloride and tetraethyl orthosilicate crosslinker, the reaction time, the solvent, etc. Interestingly, it was found that the conductivity was strongly affected by the nature of the solvents and their amount in pyrrole solution. When the weight ratio of methanol/pyrrole is 1 : 1, the conductivity was as high as 1.1 S/cm, increased by two orders of magnitude compared to that without solvent, and the mechanical properties was good. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1368–1373, 2001
PTC effect in carbon black‐filled ethylene–propylene–diene terpolymer systems
Authors: He Xiujuan , Wang Lijie , Chen Xinfang 
Published: August 2002

AbstractThe positive temperature coefficient (PTC) effects of carbon black (CB)‐filled semicrystalline and amorphous ethylene–propylene–diene terpolymer (EPDM) composites were studied. The semicrystalline EPDM/CB composite exhibited a low PTC effect followed by a pronounced negative temperature coefficient (NTC) effect, while the amorphous EPDM/CB composite exhibited only an NTC effect. By the effect of γ‐ray irradiation, not only was the NTC effect of the composites eliminated, but also a high PTC effect appeared. The PTC intensity reached as high as six orders of magnitude even for an amorphous EPDM/CB composite and the PTC transition temperature decreased with the irradiation dose. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1571–1574, 2001
Study of mechanical and rheological behaviors of linear and branched polycarbonates blends
Authors: Lyu Min‐Young , Lee Jae Sik , Pae Youlee 
Published: August 2002

AbstractA study of the mechanical and rheological properties of linear and branched polycarbonates blends is presented. Phase separations of the blends were checked through DSC and SEM, and, subsequently, mechanical and rheological properties were investigated. Phase separations were not observed in the blends. The mechanical properties were examined through tensile, flexural, and impact tests. All the mechanical properties of the blends were relatively independent of the compositions. For study of the rheological properties, melt viscosity, storage and loss moduli, and melt tension of the blends with various compositions were examined at various temperatures. The dependence of the viscosity on the molecular weight was also studied. As the content of branched polycarbonate increases, the dependence of the viscosity on the molecular weight and the shear thinning behavior became more marked. Melt tensions were also increased as the branched polycarbonate content increased in the blends for all tested temperatures. In this study, the blend systems which have same mechanical properties but different rheological properties can be obtained through blending of linear and branched polycarbonates. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1814–1824, 2001
Recycling of commingled plastics waste containing polypropylene, polyethylene, and paper
Authors: Mehrabzadeh M. , Farahmand F. 
Published: August 2002

AbstractPolymer waste recycling is a major technical problem, because large amounts of synthetic polymers are produced every day and polymeric wastes are gathered from municipal solid wastes. There are a few polyolefins, such as polyethylene (PE) and polypropylene (PP) with huge amounts of paper in the waste materials. In order to recycle the commingled plastics waste that contains paper, hydrolytic treatment is needed prior to conventional processing. In this project, the optimum conditions of hydrolytic treatment of paper and the mechanical properties and morphological state of different compositions of PP high‐density PE (HDPE) blends with paper were studied. Ethylene‐propylene‐diene copolymer (EPDM) was added to improve the mechanical properties of blends. The results show that the hydrolytic treatment of paper improves the mechanical properties, such as the tensile strength and modulus of the PP/HDPE/paper composites relative to the untreated samples, and up to 30% paper can be added to commingled PP and HDPE blends. The EPDM was used as an impact modifier. The plastics waste containing paper can be used in applications such as artificial wood. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2573–2577, 2001
Heating simulation of multilayer preforms
Authors: Lebaudy Ph. , Grenet J. 
Published: August 2002

AbstractIn the area of beverage packaging, the barrier properties (to gases, water, organic vapors/flavors) are parameters of great importance. For poly(ethylene terephtalate) (PET), largely used in bottling, the improvement of these barrier properties upon biaxial orientation is a direct result of both the level of crystallinity as well as the orientation of the material. However, even with higher crystallinity and orientation for some applications, the PET barrier properties are not adequately efficient and thus multilayer polymer materials must be used to make the bottles. During plastic‐forming processes, the semifinished multilayer thermoplastic products (such as a preform) must be heated to a rubberlike state. Experiments on PET reveal that temperatures either below or close to the glass transition (Tg) are essential to achieve principally oriented glassy structure and that the crystalline structure could be enhanced as well by thermal or high‐drawing treatments. Because of the great differences in the stretching ratio inside the preform and the thermomechanical behavior of the materials, a good stretching process requires that the material have a nonuniform temperature profile. A model is developed to calculate temperature distribution in multilayer preforms. This model is a useful tool for understanding the heating stage of thermoplastic products and is suitable to control and optimize industrial processes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2683–2689, 2001
Plasticization of cellulose diacetate by reaction with maleic anhydride, glycerol, and citrate esters during melt processing
Authors: Lee Seung‐Hwan , Shiraishi Nobuo 
Published: August 2002

AbstractTo accomplish the stable internal plasticization of cellulose diacetate (CDA), maleic anhydride (MAH) and glycerol (Gly) were used as reactive plasticizers. The plasticization method used was based on a melt‐processing reaction of CDA with MAH and Gly. MAH and Gly (MG)‐plasticized CDA showed stiff and brittle properties; that is, low elongation at break and high modulus. Thus, citrate esters were used as coplasticizers to improve physical properties. The resulted plasticized materials were optically clear, and showed attractive mechanical properties. The grafting of MG oligoesters to the free hydroxyl groups in CDA and their homo‐oligomerization were accelerated by two‐step kneading process, and verified by FTIR and GPC measurements. Differential scanning calorimeter (DSC) analysis revealed decreases of 80–100°C in the glass transition temperature (Tg) of CDA by these plasticizations. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 243–250, 2001
Electron spin resonance spectroscopic studies on microheterogeneity of crosslinked polymers. IV. Correlation between void evaluation of crosslinked resin and microgelation in monomethacrylate/dimethacrylate copolymerizations
Authors: Matsumoto Akira , Nishizawa Kazuyoshi , Yamashita Yukihiko , Morita Takehiko , Aota Hiroyuki 
Published: August 2002

AbstractElectron spin resonance spectroscopic studies on the microheterogeneity of crosslinked polymers were performed to ascertain the correlation of the void evaluation of monomethacrylate/dimethacrylate (DMA) cured resins with the microgel formation before gelation in their crosslinking copolymerizations. Lauryl methacrylate (LMA) was added to methyl MA (MMA)/ethylene DMA (EDMA) copolymerization because the addition of LMA reduces the occurrence of intramolecular crosslinking by the steric hindrance of bulky long‐chain alkyl groups, leading to the formation of a less densely crosslinked microgel core and a less microheterogeneously crosslinked resin. Then MMA/vinyl laurate (VL)/EDMA terpolymerization was performed because the polymerizability of conjugated methacryloyl groups belonging to MMA and EDMA is markedly high compared with the unconjugated vinyloxycarbonyl group of VL. Thus, enhanced microheterogeneity for MMA/VL/EDMA terpolymerization would be induced as compared with MMA/EDMA copolymerization. Finally, allyl MA (AMA) and vinyl MA (VMA) crosslinkers were used in place of EDMA because in the polymerizations of AMA and VMA having two types of carbon–carbon double bonds of different reactivities there was no microgelation observed up to the gel‐point conversion. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1187–1192, 2001
Surface graft copolymerization of 2‐hydroxyethyl methacrylate onto low‐density polyethylene film through corona discharge in air
Authors: Lei Jingxin , Liao Xia 
Published: August 2002

AbstractThe corona discharge technique was explored as a means of forming chemically active sites on a low‐density polyethylene (LDPE) film surface. The active species thus prepared at atmospheric pressure in air was exploited to subsequently induce copolymerization of 2‐hydroxyethyl methacrylate (HEMA) onto LDPE film in aqueous solution. The results showed that with the corona discharge voltage, reaction temperature, and inhibitor concentration in the reaction solution the grafting degree increased to a maximum and then decreased. As the corona discharge time, reaction time, and HEMA concentration in the reaction solution increased, the grafting degree increased. With reaction conditions of a 5 vol % HEMA concentration, 50°C copolymerization temperature, and a 2.0‐h reaction time, the degree of grafting of the LDPE film reached a high value of 158.0 μg/cm2 after treatment for 72 s with a 15‐kV voltage at 50 Hz. Some characteristic peaks of the grafted LDPE came into view at 1719 cm−1 on attenuated total reflectance IR spectra (CO in ester groups) and at 531 eV on electron spectroscopy for chemical analysis (ESCA) spectra (O1s). The C1s core level ESCA spectrum of HEMA‐grafted LDPE showed two strong peaks at ∼286.6 eV (CO from hydroxyl groups and ester groups) and ∼289.1 eV (OCO from ester groups), and the C atom ratio in the CO groups and OCO groups was 2:1. The hydrophilicity of the grafted LDPE film was remarkably improved compared to that of the ungrafted LDPE film. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2881–2887, 2001
Influence of hot‐melt extrusion and compression molding on polymer structure organization, investigated by differential scanning calorimetry
Authors: Sarraf A. G. , Tissot H. , Tissot P. , Alfonso D. , Gurny R. , Doelker E. 
Published: August 2002

AbstractA blend of a pullulan polymer and 1,2,6‐hexanetriol as a plasticizer were used to study the effect of melt processing techniques on the physical properties of the resulting materials. The main advantage of pullulan is its linear polysaccharide chain model structure. Hot‐melt extrusion and compression molding were performed under the same temperature and pressure conditions. The materials obtained were analysed by differential scanning calorimetry. For the first time, the comparative effect of the two processing techniques, i.e., extrusion and compression molding, on the polymer arrangement is reported. Endothermic events resulted from the melt extrusion process were shown to be related to different structures of oriented populations of macromolecules and to microphase separation. Orientation was enhanced by cooling the extrudate at the die exit, with a corresponding increased enthalpy from 34.7 to 51.4 J/g. In contrast, when using compression molding, the endotherm was less marked (11.9 J/g), suggesting less orientation, but the shape of the thermogram was quite similar to that of the extrudate. In both cases, we observed a loss of orientation when the molded materials were milled. A semiquantitative kinetic study of the disorientation process of the extrudate upon isothermic tempering suggests that a disorientation phenomenon occurs at the same time as a swelling process due to the presence of microphase separation. The extrudate was shown to be stable at 25°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3124–3132, 2001
Synthesis of water‐soluble polymers containing sulfonic acid and amine moieties for the recovery of metal ions using ultrafiltration
Authors: Rivas Bernabé L. , Pooley S. Amalia , Luna Maribel , Geckeler Kurt E. 
Published: August 2002

AbstractCopolymers from 2‐acrylamido‐2‐methyl‐propane sulfonic acid (APSA) and N‐acryloyl‐N‐methyl piperazine (AP) were synthesized by radical polymerization with ammonium peroxydisulfate as the initiator. The copolymerization yield ranged between 93 and 95%. The copolymers were completely water soluble, and were characterized by FTIR and NMR spectroscopy. The copolymer composition was determined from elemental analysis through the S/C ratio. The binding capacity for metal ion was studied by the LPR technique at different pH and filtration factors. The retention depended strongly on the pH and on the copolymer composition. With increasing pH and increasing content of APSA units in the copolymer, the metal ion retention increased. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 22–30, 2001
Preparation and application of chiral recognizable thermosensitive polymers and hydrogels consisting of N‐methacryloyl‐s‐phenylalanine methyl ester
Authors: Sugiyama Kazuo , Rikimaru Satoshi , Okada Yoshiharu , Shiraishi Kohei 
Published: August 2002

AbstractAmphiphilic random copolymers, poly(R‐HPMA‐co‐S‐PAM) and poly(HPMA‐co‐S‐PAM), were prepared by radical copolymerization of N‐methacryloyl‐(S)‐phenylalanine methyl ester (S‐PAM) and N‐[(R)‐2‐hydroxypropyl]methacrylamide (R‐HPMA) or N‐(2‐hydroxypropyl)methacrylamide (HPMA) with various molar ratios of R‐HPMA (or HPMA) (m) to S‐PAM (n). Either aqueous solution of poly(R‐HPMA‐co‐S‐PAM) with the molar ratio of m : n = 0.81 : 0.19 or poly(HPMA‐co‐S‐PAM) with the molar ratio of m : n = 0.79 : 0.21 exhibited the lower critical solution temperature (LCST) at 16°C. The LCST in the presence of (S)‐(−)‐phenylalanine (S‐Phe) shifted from 16 to 20°C and 18°C for poly(R‐HPMA‐co‐S‐PAM) and poly(HPMA‐co‐S‐PAM), respectively, whereas the LCST did not shift in the presence of (R)‐(+)‐phenylalanine (R‐Phe). Thermosensitive Gel(R‐HPMA‐co‐S‐PAM) and Gel(HPMA‐co‐S‐PAM) were also prepared from radical copolymerization of S‐PAM and R‐HPMA or HPMA in the presence of N,N′‐ethylenebisacrylamide (EBAAm) as a crosslinker. When the gels shrunk at 40°C, the release of dansyl‐(R)‐phenylalanine (Dans‐R‐Phe) from the gel in which loaded Dans‐R‐Phe occurred was more easily done than that of Dans‐S‐Phe from the gel that loaded Dans‐S‐Phe. Thus, these thermosensitive copolymers and gels were found to exhibit chiral recognition for phenylalanine derivatives. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 228–236, 2001
Study of exchange reaction in polycarbonate‐modified polybenzoxazine via model compound
Authors: Ishida Hatsuo , Lee Yu‐Hsin 
Published: August 2002

AbstractThe chain fragmentation in polycarbonate (PC) and polybenzoxazine blend upon thermal polymerization is investigated by size exclusion chromatography with the aid of monofunctional benzoxazine model compound. Molecular weight reduction of PC polymer via transesterification between the hydroxyl groups of ring‐opened benzoxazine and the carbonate groups from PC was observed. In addition, excess heat of reaction compared to the expected value is detected from differential scanning calorimetry and is assigned to the exotherm associated with the exchange reaction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1848–1855, 2002