bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reinforcement of peroxide‐cured styrene–butadiene rubber vulcanizates by mathacrylic acid and magnesium oxide
Authors: Yin Dehui , Zhang Yong , Zhang Yinxi , Peng Zonglin , Fan Yongzhong , Sun Kang 
Published: October 2002

AbstractThrough the neutralization of magnesium oxide (MgO) and methacrylic acid (MAA), magnesium methacrylate [Mg(MAA)2] was in situ prepared in styrene–butadiene rubber (SBR) and used to reinforce the SBR vulcanizates cured by dicumyl peroxide (DCP). The experimental results show that the mechanical properties, dynamic mechanical properties, optical properties, and crosslink structure of the Mg(MAA)2‐reinforced SBR vulcanizates depend on the DCP content, Mg(MAA)2 content, and the mole ratio of MgO/MAA. The formulation containing DCP 0.6–0.9 phr, Mg(MAA)2 30–40 phr, and MgO/MAA mole ratio 0.50–0.75 is recommended for good mechanical properties of the SBR vulcanizates. The tensile strength of the SBR vulcanizates is up to 31.4 MPa when the DCP content is 0.6 phr and the Mg(MAA)2 content is 30 phr. The SBR vulcanizate
have good aging resistance and limited retention of tensile strength at 100°C. The SBR vulcanizates are semitransparent, and have a good combination of high hardness, high tensile strength, and elongation at break. The Tg values of the SBR vulcanizates depend largely on the DCP content, but depend less on the Mg(MAA)2 content and the MgO/MAA mole ratio. The contents of DCP, Mg(MAA)2, and the MgO/MAA mole ratio have also great effects on the E′ values of the vulcanizates. The salt crosslink density is greatly affected by the Mg(MAA)2 content and MgO/MAA mole ratio, but less affected by the DCP content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2667–2676, 2002
Compatibility and thermal properties of poly(acrylonitrile–butadiene–styrene) copolymer blends with poly(methyl methacrylate) and poly(styrene‐co‐acrylonitrile)
Authors: Li Qifang , Tian Ming , Kim Donggil , Zhang Liqun , Jin Riguang 
Published: October 2002

AbstractThe mechanical and heat‐resistant properties of acrylonitrile–butadiene–styrene (ABS) binary and ternary blends were investigated. The relationship of compatibility and properties was discussed. The results show that poly(methyl methacrylate) (PMMA) and styrene–maleic anhydride (SMA) can improve the thermal properties of conventional ABS. The Izod impact property of ABS/PMMA blends increases significantly with the addition of PMMA, whereas that of ABS/SMA blends decreases significantly with the addition of SMA. Blends mixed with high‐viscosity PMMA are characterized by higher heat‐distortion temperature (HDT), and their heat resistance is similar to that of blends mixed with SMA. For high‐viscosity PMMA, from 10 to 20%, it is clear that blends appear at the brittle–ductile transition, which is related to the compatibility of the two phases. TEM micrographs show low‐content and high‐viscosity PMMA in large, abnormally shaped forms in the matrix. Compatibility between PMMA and ABS is dependent on both the amount and the viscosity of PMMA. When the amount of high‐viscosity PMMA varied from 10 to 20 wt %, the morphology of the ABS binary blends varied from poor to satisfactory compatibility. As the viscosity of PMMA decreases, the critical amount of PMMA needed for the compatibility of the two phases also decreases. SMA, as a compatibilizer, improved the interfacial adhesiveness of ABS and PMMA, which results in PMMA having good dispersion in the matrix. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2652–2660, 2002
Adhesion of spray primers to plasma polymer coatings
Authors: Yasuda H. K. , Yu Q. S. , Reddy C. M. , Moffitt C. E. , Wieliczka D. M. 
Published: October 2002

AbstractThe adhesion failure of a primer on a plasma‐polymer‐deposited substrate surface could occur at the interface of the substrate/plasma polymer or at the interface of the plasma polymer/primer. We examined the adhesion of spray (solventborne or waterborne) primers on plasma polymer coated substrate with the substrate/plasma polymer systems in which the adhesion of the plasma polymer of trimethylsilane (TMS) to the substrate was good. Waterborne primers adhered well to quite hydrophobic plasma polymer surfaces, except the untreated surface of TMS. The plasma polymer of TMS appeared to contain a significant amount of oligomers, which were not in the three‐dimensional network of the plasma polymer coating and caused poor adhesion of primers. The plasma treatment of the deposited plasma polymer of TMS increased the adhesion characteristics of the primers dramatically. The oxygen‐plasma treatment, however, made the interface water sensitive and made the wet adhesion poor. The argon‐plasma treatment of the plasma polymer of TMS was found to be a viable process that yielded excellent adhesion of spray primers. The plasma polymer of TMS deposited by a closed system, without further plasma treatment, yielded an excellent foundation for the application of spray primers. Waterborne, nonchromated primers adhered exceedingly well and survived 8 h of boiling in water (with a scribed surface) and became virtually nonstrippable by conventional stripping agents. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1443–1457, 2002
Physicochemical investigation of radiation‐grafted poly(acrylic acid)‐graft‐poly(tetrafluoroethylene–ethylene) copolymer membranes and their use in metal recovery from aqueous solution
Authors: El‐Sawy Naeem M. , Al Sagheer Fakhreia A. 
Published: October 2002

AbstractET‐g‐PAAc membranes were obtained by radiation grafting of acrylic acid onto poly(tetrafluoroethylene–ethylene) copolymer films using a mutual technique. The ion selectivity of the grafted membranes was determined toward K+, Ag+, Hg2+, Co2+, and Cu2+ in a mixed aqueous solution. The ion‐exchange capacity of the grafted membranes was measured by back titration and atomic absorption spectroscopy. The Hg2+ ion content of the membrane was more than that of either the K+ or Ag+ ions. The presence of metal ions in the membranes was studied by infrared and energy‐dispersive spectroscopy measurements. Scanning electron microscopy of the grafted and metal‐treated grafted membranes showed modification of the morphology of the surface due to the adsorption of K+ and Ag+ ions. No change was observed for the surface of the membrane that was treated with Hg2+ ions. The thermal stability of different membranes was improved more with Ag+ and Hg2+ ions than with K+ ions. It was found that the modified grafted membranes possessed good hydrophilicity, which may make them promising candidates for practical applications, such as for cation‐exchange membranes in the recovery of metals from an aqueous solution. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2692–2698, 2002
Synthesis and fluorescence of polymeric triphenylamine obtained by oxidative‐coupling polymerization
Authors: Zhan Caimao , Cheng Zhangang , Zheng Jinyun , Zhang Wei , Xi Yang , Qin Jingui 
Published: October 2002

AbstractWe prepared triphenylamine (TPA)‐containing polymers by a direct oxidative‐coupling method, which showed high thermostability, good solubility, high quantum efficiency, and blue light emission. The polymers are characterized by Fourier transform infrared spectroscopy, 1H‐NMR, ultraviolet–visible spectroscopy, thermogravimetric analysis, elemental analysis, and fluorescence spectra. The homopolymeric TPA (PTPA) was fairly soluble in CCl4 and toluene, with a quantum yield of 0.38 relative to Rhodamine B in toluene solution, and showed blue light emission in solid‐state film. The TPA–stilbene copolymers were more soluble than the PTPA and showed violet to green light emission in solid‐state film, depending on the TPA moiety contents, from which a pure blue light emission could be obtained. The emitting quantum efficiency of the copolymers measured in toluene solution was from 0.57 to 0.78 relative to Rhodamine B. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2718–2724, 2002
Adhesion of the plasma polymer of trimethylsilane to aluminum alloys
Authors: Yasuda H. K. , Yu Q. S. , Reddy C. M. , Moffitt C. E. , Wieliczka D. M. 
Published: October 2002

AbstractThe adhesion of a plasma polymer and the corrosion protection offered to aluminum alloy substrates depends on the cleanliness of the substrate surface and the state of oxides on the aluminum alloy surface. Both factors are dependent on what type of alloy is used, and consequently, the best preparation of the substrate surface differs on the type of aluminum alloy. Oxygen plasma treatment is effective for the elimination of organic surface contamination, but plasma treatment, such as that of mixed argon and hydrogen, cannot be used to modify the surface state of oxides on these alloys. This is because oxides of aluminum are stable and thus resist plasma modification, and prolonged plasma treatment has been observed to change concentrations of alloy components at the surface due to the heating of the alloy. Chemical cleaning of the surface is necessary before the application of the plasma polymer used for corrosion protection enhancement. Once the surface was properly prepared, a plasma polymer of trimethylsilane (TMS), prepared by cathodic polymerization, adhered well to aluminum alloys investigated in this study. Major adhesive failure, however, occurred as a consequence of reactor contamination when hexafluoroethane (HFE) plasma treatment of initially formed TMS plasma polymers was employed. Plasma pretreatment of the substrate with O2 or postplasma treatment of the plasma polymer of TMS with Ar (instead of HFE) was effective in eliminating the surface‐contamination effect on the adhesion. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1387–1398, 2002
Depolymerization of poly(ethylene terephthalate) waste
Authors: Shukla S. R. , Kulkarni K. S. 
Published: October 2002

AbstractPoly(ethylene terephthalate) waste was depolymerized with ethylene glycol in the presence of different catalysts, two conventional metal catalysts (zinc acetate and lead acetate) and two alkalies (sodium carbonate and sodium bicarbonate). The resulting monomer bis(2‐hydroxy ethylene terephthalate) was characterized by thin layer chromatography, melting point, IR spectroscopy, differential scanning calorimetry, and elemental analysis. The results show that the qualitative and quantitative yields of the monomer obtained with alkalies as catalysts were most comparable with the conventional heavy metal catalysts, thus providing a further advantage for the recycling of polyester waste for the cause of environmental pollution abatement. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1765–1770, 2002
Novel polymeric aromatic lithium sulfonylimides as salts for polymer electrolytes
Authors: Nie Jin , Liu Dan‐Fan , Wang Xu‐Dong , Liu Lie‐Wei 
Published: October 2002

AbstractThree new polymeric aromatic lithium sulfonylimides were used as salts in high molecular weight poly(ethylene oxide) (PEO) electrolytes. Their conductivity and electrochemical stability behaviors were investigated. The electrolytes with lithium poly[4,4′‐(hexafluoroisopropylidene)diphenoxy]sulfonylimide (LiPHFIPSI) showed a better conductive performance compared with the other two lithium salts. The best conductivity was obtained for PEO/LiPHFIPSI EO/Li = 16 (1.90 × 10−4 S/cm at 60°C). Thermal analysis indicated that the salts effectively decreased the crystallinity of PEO. Moreover, the electrolytes also had good electrochemical stability and their oxidative potential was to 5.5 V versus Li/Li+. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1802–1805, 2002
Rheology of polymeric solutions I. Zero shear conditions
Authors: Yasnovsky V. M. 
Published: October 2002

AbstractBased on kinetic considerations, the following equation, connecting the zero‐shear viscosity of polymeric solutions with temperature and the molecular weight and concentration of the polymer was derived: RTln ηR = KBφMn /(1 + BφMn), where ηR is relative viscosity (i.e., the ratio of the solution viscosity to the solvent viscosity); K represents a change in enthalpy of viscous flow from a pure solvent to a pure polymer at the same temperature or from a polymer of low molecular weight (M) to one of higher molecular weight, and has the dimensions of energy (e.g., J/mol) because the ratio BφMn/(1 + BφMn) is dimensionless; φ is the volume or molar fraction of a polymer in solution (concentration units can be used in dilute solutions); B is a constant related to the stiffness of the chains of the polymer in a given solvent; and at BφMn >> 1, ln ηR = K/RT. The equation describes published data on the zero‐shear viscosity of four polar and nonpolar polymers in nine solvents with R2 > 0.98. This approach allows the use of solutions of moderate concentrations for the characterization of polymers and opens a way for a single‐point degree of polymerization (DP) determination of polymers at moderate concentrations if constants K, B, and n of the equation are known. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2064–2073, 2002
Preparation of sulfonated novel poly(bis[4‐(3‐aminophenoxy) phenyl]sulfone pyromellite)imide derivatives by heterogeneous sulfonation
Authors: Jeon Jong‐Young , Shim Bomg‐Seob 
Published: October 2002

AbstractSulfonated poly(bis[4‐(3‐aminophenoxy)phenyl]sulfone pyromellite)imide derivatives with various ion‐exchange capacities were prepared by heterogeneous sulfonation with chlorosulfonic acid. The effects of sulfonating agent concentration, reaction temperature, and reaction time were investigated. The mechanical and thermal properties, contact angle, change of polydispersity, and solubility were calculated for studying change of their properties. The reactions were effective, when the temperature is <10 °C and the concentration of chlorosulfonic acid is between 0.05 and 0.1 M. The value of ion‐exchange capacity was increased with reaction time, reaction temperature, and concentration of sulfonating reagent. Thermal and mechanical properties were nearly unchanged according to the degree of sulfonation, but the hydrophilicity indirectly measuring contact angle was increased with increasing the value of ion‐exchange capacity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1881–1887, 2002
Influence of filming process on macromolecular structure and organization of a medical segmented polyurethane
Authors: Guignot C. , Betz N. , Legendre B. , Le Moel A. , Yagoubi N. 
Published: October 2002

AbstractA medical segmented polyurethane, Tecoflex®, based on methylene bis(p‐cyclohexyl isocyanate) and 1,4‐butanediol as hard segments (HS), and poly(tetramethylene glycol) as soft segments (SS), was studied to evaluate the influence of different filming procedures on macromolecular structure and organization. Size‐exclusion chromatography (SEC) and Fourier transform infrared (FTIR) spectroscopy were used to highlight differences between solvent‐cast and hot compression‐molded films (160 to 200°C). For compression‐molded films, FTIR spectra showed weakened vibration bands attributed to HS and SS groups; SEC results indicated a decrease of Mn and Mw molecular weights that was dependent on processing time and temperature. These modifications were the result of both thermooxidation of soft segments and thermal dissociation of urethane linkages. Concerning solvent‐cast films, no chemical or molecular modifications were observed. Moreover, we have highlighted that this procedure enhanced macromolecular organization: the carbonyl stretching region presented several bands assigned to free carbonyls and H‐bonded carbonyls with different environments. Particularly, we observed a band at 1660 cm− 1 reported in only one publication; we demonstrated that it originated from a bonded carbonyl in a well‐ordered structure. We have concluded that solvent casting has to be preferred because it enhances macromolecular ordering without chain degradation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1970–1979, 2002
Enzymatically degradable prodrugs: A novel methodology for drug linkage
Authors: Padmaja T. , Lele B. S. , Deshpande M. C. , Kulkarni M. G. 
Published: October 2002

AbstractWe have synthesized a novel enzymatically degradable prodrug system based on poly(ethylene glycol) (PEG) and tyrosine units by employing a synthetic methodology which eliminated the use of conventional blocking and deblocking methodology used for chemical linkage of drug molecule to the pendant NH2 group of amino acid. A diester of PEG (6 kDa) and tyrosine hydrochloride was synthesized by dicyclohexyl carbodiimide (DCC)‐mediated condensation. In the second stage, oligomers were prepared by condensing phenolic OH groups of tyrosine in the diester with sebacic acid, using DCC. Finally, the hydrochloride salt of tyrosine in the oligomer was treated with triethylamine to activate NH2 groups, which were reacted with benzoyl chloride to obtain a model prodrug system. The products synthesized were characterized by IR, 1H‐NMR, and GPC. The spectral data were in accordance with the proposed structures of products. Chymotrypsin‐catalyzed degradation of the oligomers was characterized by both MW measurements and Ninhydrin assay for free tyrosine. Degradation studies indicated that the rate of main‐chain degradation (ester hydrolysis) is higher than that of the side chain (amide hydrolysis). This new, simple methodology should be useful for conjugating a variety of bioactive molecules to enzymatically degradable PEG–amino acid based polymers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2108–2118, 2002
Microemulsion and conventional emulsion copolymerizations of methyl methacrylate with acrylonitrile
Authors: Ramana Reddy G. V. , Prasad Babu Y. Phani , Rami Reddy N. Subba 
Published: October 2002

AbstractThe microemulsion (ME) and conventional emulsion (CE) copolymerizations of methyl methacrylate (MMA) with acrylonitrile (AN) are carried out at 70°C by employing sodium lauryl sulphate (SLS) and n‐octanol (OA) as surfactant and cosurfactant, respectively, and potassium persulphate (KPS) as initiator. The copolymerization reactions are arrested at lower conversions, and the copolymers prepared are characterized by FTIR, NMR, TG/DTA, and GPC techniques. The reactivity ratios for microemulsion and conventional emulsion copolymerizations are evaluated by Fineman‐Ross (F‐R), Kelen‐Tüdös (K‐T), and Mayo‐Lewis (M‐L) graphical methods. The K‐T method yields the reactivity ratios of MMA (rMMA) and AN (rAN) as 2.03 ± 0.02 and 0.10 ± 0.02, and 1.97 ± 0.02 and 0.13 ± 0.02, respectively, for ME and CE copolymerization methods. The results are compared with the literature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1503–1510, 2002
Morphology and mechanical properties of polypropylene/organoclay nanocomposites
Authors: Svoboda Petr , Zeng Changchun , Wang Hua , Lee L. James , Tomasko David L. 
Published: October 2002

AbstractPolypropylene (PP) nanocomposites were prepared by melt intercalation in an intermeshing corotating twin‐screw extruder. The effect of molecular weight of PP‐MA (maleic anhydride‐ modified polypropylene) on clay dispersion and mechanical properties of nanocomposites was investigated. After injection molding, the tensile properties and impact strength were measured. The best overall mechanical properties were found for composites containing PP‐MA having the highest molecular weight. The basal spacing of clay in the composites was measured by X‐ray diffraction (XRD). Nanoscale morphology of the samples was observed by transmission electron microscopy (TEM). The crystallization kinetics was measured by differential scanning calorimetry (DSC) and optical microscopy at a fixed crystallization temperature. Increasing the clay content in PP‐ MA330k/clay, a well‐dispersed two‐component system, caused the impact strength to decrease while the crystallization kinetics and the spherulite size remained almost the same. On the other hand, PP/PP‐MA330k/clay, an intercalated three‐component system containing some dispersed clay as well as the clay tactoids, showed a much smaller size of spherulites and a slight increase in impact strength with increasing the clay content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1562–1570, 2002
Preparation and characterization of low molecular weight silk fibroin by high‐temperature and high‐pressure method
Authors: Kang Gyung‐Don , Lee Ki‐Hoon , Shin Bong‐Seob , Nahm Joong‐Hee 
Published: October 2002

AbstractA low molecular weight silk fibroin powder (LMSF) was prepared through high temperature (200°C) and high pressure (20 kgf/cm2), without any addition of chemicals. The carbonized adducts produced during this process were then removed by treatment with activated charcoal. The yield of LMSF by this preparation method was over 60% after the removal of carbonized adducts by using activated charcoal. Amino acid analysis showed an observable decrease in contents of serine and tyrosine in LMSF prepared by this method, as compared to those prepared by neutral salt. The molecular weight of this LMSF was also observably decreased with an increase in the reaction time. From the measurements of differential scanning calorimeter (DSC) and thermal gravimetric analyzer (TGA), thermal properties of LMSF through high temperature and high pressure were also decreased as compared to those produced by neutral salts. In addition, wide‐angle X‐ray diffraction (WAXD) patterns showed that the crystallinity of LMSF differed from that of the original silk fibroin. It can be said that the preparation method of LMSF in this study is a simple, economical, and environmentally compatible process with many advantages. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2890–2895, 2002
Effect of adding other metal ions on the removal of Cd2+ by the CoAlPO4‐5/polysulfone membrane
Authors: Lin Shiow‐Shyung , Chen Ming‐Ten , Chang Dong‐Jang , Chen Shih‐Hsiung , Tsai Yi‐Ting 
Published: October 2002

AbstractBased on our previous work, performance of separation of Cd2+ by the CoAlPO4‐5/polysulfone membrane was not as good as that of the other metal ions. This could be significantly improved by the addition of other metal ions into the Cd2+ solution. The metal ions added were those with larger hydrated radius than that of Cd2+. When Mg2+ and Ca2+ were added, the rejection rate of Cd2+ could be increased from about 50% ([Cd2+] = 50 ppm) to nearly 100% and the rate would increase with concentration of Mg2+ and Ca2+. However, when the added ions were Fe2+ and Mn2+, although the performance of Cd2+ removal was still high, the rejection rate would inversely decrease with increasing concentration of Fe2+ and Mn2+. These phenomena were mainly attributable to the effect of hydrated ion and the effect of lowered pH value induced by the hydrolysis of the solution. As to the addition of Al3+, although the rejection rate would decrease with increasing Al3+ concentration up to 100 ppm, an abrupt increase was observed at 150 ppm, which was thought to be attributable to the concentration polarization effect caused by the formation of the high valence [Aln(OH)m](3[supi]n−[supi]m)+ complex. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2172–2177, 2002