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NOVEL HYPERBRANCHED POLY(PHENYLENE OXIDE)S WITH PHENOLIC TERMINAL GROUPS: EFFECTS OF REACTION TIME AND CORE MOLECULES ON THE MOLECULAR WEIGHT AND POLYDISPERSITY 被引量:1
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作者 李效玉 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2006年第4期413-419,共7页
A novel hyperbranched poly(phenylene oxide) (HPPO) with phenolic terminal groups was prepared from 4-bromo-4',4"-dihydroxytriphenylmethane as AB2 monomer in dimethylsulfoxide (DMSO) via a modified Ullmann reac... A novel hyperbranched poly(phenylene oxide) (HPPO) with phenolic terminal groups was prepared from 4-bromo-4',4"-dihydroxytriphenylmethane as AB2 monomer in dimethylsulfoxide (DMSO) via a modified Ullmann reaction. The molecular weight and polydispersity (PD) of the resulting polymers increased with increasing reaction time. In the presence of core molecules (bisphenol A and 1,3,5-trihydroxybenzene), which have the similar molecular backbones to the reactive monomer, the molecular weight could be controlled by varying the core-to-monomer ratio. Incorporation of a very small amount of core molecules could lead to a higher molecular weight as compared with that without the addition of core molecules. However, when the core content reached certain extent, the molecular weight would decrease with the further increase in the core content. A new similar behavior of control over the PD was also obtained. The resulting polymers were characterized by ^1H-NMR, ^13C-NMR, FT-IR, and GPC. 展开更多
关键词 HYpERBRANCHED polyphenylene oxide Controlled reaction Core molecule.
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The Insulator-to-Conductor Transition in Sulphonated Poly(Phenylene Oxide)Polymer membranes:Percolation Theory Approach
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作者 徐铜文 杨伟华 何炳林 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1998年第4期5-11,共7页
In this paper the percolation theory is employed to study the insulator-to-conductortransition in sulphonated poly(phenylene oxide)(SPPO) polymer membranes.The membranes withdifferent sulphonation degree were prep... In this paper the percolation theory is employed to study the insulator-to-conductortransition in sulphonated poly(phenylene oxide)(SPPO) polymer membranes.The membranes withdifferent sulphonation degree were prepared and infrared characterized.The transition thresholdwas calculated by the experimental data of membrane conductivities and the coordination numberwas thus estimated.The functional group-SO<sub>3</sub>H distribution in the membrane was evaluated inaccordance with the calculations and showed a non-random dispersion on the microscopic scale. 展开更多
关键词 poly(phenylene oxide) polymer ion exchange membrane pERCOLATION THRESHOLD
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GAS SORPTION AND TRANSPORT IN POLY (PHENYLENE OXIDE)(PPO)AND ARYL-BROMINATED PPO MEMBRANES
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作者 贾连达 F. R. SHEU +1 位作者 R.T.CHERN H.B.HOPFENBERG 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1989年第4期306-314,共9页
The apparent solubility (S), concentration-average diffusivity (D), and permeability (P), for C0_2, CH_4 and N_2 through PPO and aryl-brominated PPO at 35℃ for pressure ranging from 1 to 26 atm are reported. It is fo... The apparent solubility (S), concentration-average diffusivity (D), and permeability (P), for C0_2, CH_4 and N_2 through PPO and aryl-brominated PPO at 35℃ for pressure ranging from 1 to 26 atm are reported. It is found that P, D, and S of the membranes to all the three gases vary with the extent of bromination. S increases with the increase of the percent of bromine in each case, but D to CO_2 increases remarkably only at higher degree of brominafion, and therefore, P to CO_2 is increased by more than 100% over a wide range ofpressure in the case. The solubility data are well described by the dual mode sorption model. It is found that the gas molecules sorbed by the Langmuir mode are relatively more immobilized and the contribution of the nonequilibrinm character of the polymer to gas permeation increases obviously for CO_2 and is hardly changed for CH_4 with increasing bromine content. These observations are interpreted in terms of changes in specific free volume (SFV)and the cohesive energy density (CED) of the polymers. 展开更多
关键词 poly (phenylene oxide) (ppO) BROMINATION Membrane permeability.
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EFFECT OF SOLVENT COMPOSITION ON THE SULFONATION DEGREE OF POLY(PHENYLENE OXIDE) (PPO)
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作者 徐铜文 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2002年第1期53-57,共5页
This paper investigates the possibility of attaining sulphonated poly(phenylene oxide) (SPPO) with a relativelyhigher sulfonation degree. To achieve this aim, the approach we adopt is to improve the solubility of the ... This paper investigates the possibility of attaining sulphonated poly(phenylene oxide) (SPPO) with a relativelyhigher sulfonation degree. To achieve this aim, the approach we adopt is to improve the solubility of the final product in themixed solvent so that the sulfonation may take place between the bulk solutions and PPO powders even at higher sulfonationdegree. It is shown that the addition of a proper amount of dimethyl formide (DMF) to the conventional PPO-chloroformsystem can actually enhance the sulfonation effect. The solvent composition is then correlated with the sulfonation degreebased on the solubility parameters. It is interesting to find that solubility parameters between the mixed solvent and theprecipitated products keep an approximately unchanged value at about 4.9, which is just equal to that when pure chloroformis used, though the solubility parameters of both solvents increase with the content of DMF in solution. This may be the mainreason why the addition of DMF can reduce the precipitation and improve the ion exchange capacity (IEC) of SPPOpolymer. 展开更多
关键词 poly(phenylene oxide) SULFONATION Solubility parameter
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SOLID-STATE HIGH RESOLUTION NMR STUDY ON POLY (2, 6-DIMETHYL-1,4-PHENYLENE OXIDE)
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作者 晏欣 胡建治 +2 位作者 姚树人 叶朝辉 张宝真 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1995年第3期252-258,共7页
Experiments including C-13 spin-lattice relaxation, C-13 heteronuclear dipolar dephasing and H-1 spin diffusion are performed on poly (2,6-dimethyl-1,4-phenylene oxide) (PPO). The results show that the rotation of the... Experiments including C-13 spin-lattice relaxation, C-13 heteronuclear dipolar dephasing and H-1 spin diffusion are performed on poly (2,6-dimethyl-1,4-phenylene oxide) (PPO). The results show that the rotation of the methyl groups in solid PPO is partially restricted, which results in a surprisingly efficient spin diffusion between the aromatic proton and methyl proton characterized by a diffusion time of 150 mu s. The results also show that the aromatic ring in solid PPO is rigid and twisted, which causes all aromatic carbons to be chemically unequivalent. 展开更多
关键词 SOLID-STATE HIGH RESOLUTION NMR C-13 SpIN-LATTICE RELAXATION C-13 HETERONUCLEAR DIpOLAR DEpHASING H-1 SpIN DIFFUSION poly (2 6-DINIETHYL 1 4-phenylene oxide)
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PBO纤维表面改性处理的研究进展 被引量:3
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作者 杨超杰 吴喜娜 +1 位作者 魏浩 王国军 《表面技术》 EI CAS CSCD 北大核心 2024年第1期48-55,共8页
聚对苯撑苯并二噁唑(PBO)纤维因其比强度高、比模量高、耐热性好、阻燃性好以及优异的介电性能,现已在安全防护、建筑汽车等领域得到广泛应用。由于PBO纤维表面光滑、化学惰性,导致其与基体树脂界面结合差,进一步影响复合材料的整体性能... 聚对苯撑苯并二噁唑(PBO)纤维因其比强度高、比模量高、耐热性好、阻燃性好以及优异的介电性能,现已在安全防护、建筑汽车等领域得到广泛应用。由于PBO纤维表面光滑、化学惰性,导致其与基体树脂界面结合差,进一步影响复合材料的整体性能,这大大限制了PBO纤维优异综合性能的发挥,所以对PBO纤维表面进行改性处理显得尤为重要。介绍了近年来国内外针对PBO纤维不同表面改性方法及对应复合材料性能改善程度的研究进展,从PBO纤维改性方法的分类入手,阐述了各种方法的基本原理。通过对这些处理方法的比较,阐述了国内PBO纤维表面改性的研究进展,指出了国内外在PBO纤维表面改性处理上的差距,为未来的发展方向提供了参考。PBO纤维表面改性方法包括化学刻蚀法、等离子体处理、表面涂层法、化学接枝法、紫外刻蚀法、上浆剂处理等。各种改性技术各有利弊,在选择改性方法时,理应考虑达到工艺快捷有效、经济环保和无损纤维性能等指标。未来,在PBO纤维表面改性的处理方法领域,将逐步向绿色环保的上浆剂处理方向发展。 展开更多
关键词 聚对苯撑苯并二噁唑纤维 表面改性 界面 复合材料
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CRYSTAL STRUCTURE AND MORPHOLOGY OF NASCENT SAMPLES OF SYMMETRIC AROMATIC POLYESTERS——Ⅰ.POLY(P-PHENYLENE TEREPHTHALATE) 被引量:2
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作者 J.Yang J.Wang +4 位作者 G.Sidoti J.Liu F.Rybnikar M.Kaszonyiova P.H.Geil 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2003年第2期189-204,共16页
The morphology and crytal structure of poly(p-phenylene terephthalate) (PPT), prepared by confined thin filmmelt (CTFMP) and solution (CTFSP) and bulk solution polymerization, were characterized by transmission electr... The morphology and crytal structure of poly(p-phenylene terephthalate) (PPT), prepared by confined thin filmmelt (CTFMP) and solution (CTFSP) and bulk solution polymerization, were characterized by transmission electronmicroscopy, electron dimaction and molecular modeling. The unit cell is monoclinic (P2_1/a space group) with parameters a =7.89, b = 5.49, c = 12.65 A, α=γ= 90°, β=100.33°, density = 1.48 g/cm^3, the a, b and β values differing slightly from thosereported previously in the literature. A degree of variation in relative intensities of hk0 reflections in, apparently, untilted[001] ED patterns was observed from a given sample, suggesting some variation in molecular packing. ED evidence wasfound for a second phase, with [001] appearing the same as for phase Ⅱ of the related poly(p-oxybenzoate) (PpOBA)polymer. CTFMP crystals polymerized above 220℃ (up to 370℃) and CTFSP crystals polymerized at 300℃ consisted oflamellae 100-200 A thick. 展开更多
关键词 poly(p-phenylene terephthalate) Electron diffiaction Crystal structure Confined thin film melt polymerization EpITAXY Morphology
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Effect of Curing Poly(<i>p</i>-Phenylene Sulfide) on Thermal Properties and Crystalline Morphologies 被引量:1
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作者 Sungho Lee Do-Hwan Kim +3 位作者 Jae-Ha Park Min Park Han-Ik Joh Bon-Cheol Ku 《Advances in Chemical Engineering and Science》 2013年第2期145-149,共5页
Commercial poly(p-phenylene sulfide) (PPS) was thermally cured, which resulted in an increase of molecular weight due to cross-linking. Non-isothermal crystallization studies of samples cured for up to 7 days at 250?C... Commercial poly(p-phenylene sulfide) (PPS) was thermally cured, which resulted in an increase of molecular weight due to cross-linking. Non-isothermal crystallization studies of samples cured for up to 7 days at 250?C showed a monotonous increase of crystallization temperature compared to pure PPS. However, a further increase of curing time decreased the crystallization temperature. The change in the half-crystallization time (t1/2) was similar to the crystallization temperature. Thus, the cross-linking of PPS affected crystallization behaviors significantly. To a certain extent, crosslinks acted as nucleation agents, but excessive cross-linking hindered the crystallization. Morphologies observed by polarized optical microscopy suggested that thermal curing for as little as 1 day contributed to the spherulitic structure having a smaller size, that was not observed with pure PPS. 展开更多
关键词 poly(p-phenylene Sulfide) Thermal CURING Non-Isothermal Crystallization Cross-Linking CRYSTALLINE MORpHOLOGIES
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RAMAN SPECTROSCOPIC STUDY ON THE CHAIN CONFORMATION OF ELECTROSYNTHESIZED POLY(ρ-PHENYLENE)FILMS
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作者 Feng-en Chen Ming-xiao Fu +2 位作者 Fan Wang Bin Fan Gao-quan Shi 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2005年第6期681-685,共5页
Poly(p-phenylene) (PPP) films have been electrochemically deposited on mirrorlike stainless steel (SS) electrode surfaces by direct oxidation of benzene in boron trifluoride diethyl etherate (BFEE) solutions a... Poly(p-phenylene) (PPP) films have been electrochemically deposited on mirrorlike stainless steel (SS) electrode surfaces by direct oxidation of benzene in boron trifluoride diethyl etherate (BFEE) solutions at a constant applied potential of 1.7 V (versus Ag/AgCl). The chain conformations of as-grown PPP films have been studied by Raman spectroscopy. The results demonstrated that high synthesis temperature favors the formation of planar PPP, and the conformation of planar PPP can be changed into torsional PPP by cooling treatment. 展开更多
关键词 polyp-phenylene Raman spectroscopy CONFORMATION
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ELECTRICALLY CONDUCTIVE COMPOSITE PREPARED BY ELECTROCHEMICAL POLYMERIZATION OF PYRROLE IN POLY-(p- PHENYLENE TEREPHTHALAMIDE) MATRIX
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作者 毕先同 裴启兵 +1 位作者 韩宝珍 宝净生 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1991年第4期289-293,共5页
The preparation of PPy/PPTA conductive composite films by electrochemical method is presented.The first step is to cast a thin layer of poly (p-phenylene-terephthalamide) (PPTA) on a slice of Pt working electrode. The... The preparation of PPy/PPTA conductive composite films by electrochemical method is presented.The first step is to cast a thin layer of poly (p-phenylene-terephthalamide) (PPTA) on a slice of Pt working electrode. The second step is to electrochemically polymerize pyrrole on the PPTA/Pt working electrode. Both of the electrical conductivity and the mechanical properties of the PPy/PPTA composite film are better than those of the pure PPy film, and the film has excellent flexibility at low temperature, even in liquid nitrogen.The SEM picture of the cross-section of PPy,/PPTA composite film showed that the two components were well mixed.Cyclic voltammograms of PPy,/PPTA film in aqueous solution showed that the conductive films could be reduced and reoxidized. 展开更多
关键词 polypYRROLE poly (p-phenylene-terephthalamide) Conductive composite
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CRYSTAL STRUCTURE AND MORPHOLOGY OF NASCENT SAMPLES OF SYMMETRIC AROMATIC POLYESTERS——Ⅱ. POLY(p-PHENYLENE 2,6-NAPHTHALATE)
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作者 J.Yang J.Wang +4 位作者 G.Sidoti J.Liu F.Rybnikar M.Kaszonyiova P.H.Geil 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2003年第2期205-221,共17页
Confined thin film melt polymerization (CTFMP) of naphthalene chloride/hydroquinone (NCMQ, 1/1, molar)mixtures at polymerization temperatures (T_p) below ca. 300℃ resulted in relatively thick, elongated crystals. Pol... Confined thin film melt polymerization (CTFMP) of naphthalene chloride/hydroquinone (NCMQ, 1/1, molar)mixtures at polymerization temperatures (T_p) below ca. 300℃ resulted in relatively thick, elongated crystals. Polymerizationof NC/HQ above 300℃ between glass yielded well-formed lamellar crystals ca. 100 A thick. Phase Ⅰ and Ⅱ [001] EDpatterns were obtained for all T_p, the relative amount of phase Ⅰ increasing with T_p. Polymerization of naphthalenedicarboxylic acid/hydroquinione diacetate 1/1 mixtures at high T_p also yielded lamellar crystals that "curled up" off of thesubstrate. When the high temperature CTFMP polymerization was conducted between mica, aggregates of lamellae on-edgedeveloped but epitaxial growth did not occur. Epitaxial growth of lamellae between mica could be obtained, however, byconfined thin film solution polymerization, with both of the latter samples yielding apparently related ED patterns from adifferent unit cell than phase Ⅰ or Ⅱ. Fiber patterns, obtained from sheared samples, indicated considerably greater crystaldisorder than in the nascent crystals. Refinement of the phase Ⅰ unit cell parameters, based on the [001] and [01 1] EDpatterns, with modeling based on Cerius^2, suggests a monoclinic phase Ⅰ unit cell with a = 7.76, b = 5.71, c = 14.99 A, α = γ= 90°, β= 99.7°, ρ = 1.47 g/cm^3, space group P12_1/al. 展开更多
关键词 poly(p-phenylene 2 6-naphthalate Crystal structure Morphology Confined thin film melt polymerization
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Mechanical Property and Crystal Structure of Poly(p-phenylene terephthalamide)(PPTA) Fibers during Heat Treatment under Tension
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作者 严冬东 陈蕾 +6 位作者 曹煜彤 鲁超风 于俊荣 刘兆峰 诸静 王彦 胡祖明 《Journal of Donghua University(English Edition)》 EI CAS 2015年第1期1-6,共6页
The relationship between property and structure of poly( p-phenylene terephthalamide)( PPTA) was investigated for the purpose of obtaining products with better performance. PPTA fiber subjected to heat treatment under... The relationship between property and structure of poly( p-phenylene terephthalamide)( PPTA) was investigated for the purpose of obtaining products with better performance. PPTA fiber subjected to heat treatment under different conditions was intensively studied. Simultaneous wide-angle X-ray diffraction( WAXD) technique was introduced to study the changes of crystal structure. It was found that the tensile modulus was strongly sensitive to the levels of temperature and tension. The structure parameters including crystal size and crystal orientation after heat treatment evolve similarly to the tensile modulus,indicating a direct structure-property relationship. The lattic c-dimension increases after heat treatment and is greatly affected by the tension. An optimal temperature can be found around 400 ℃,where big change can happen in the crystal structure due to α-relaxation in the crystal region as supported in dynamic mechanical analysis( DMA). 展开更多
关键词 poly(p-phenylene terephthalamide)(ppTA) fibers heat treatment crystal structure crystal orientation mechanical properties
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The Synthesis and Electronic Characteristics of Poly(p-Phenylene Vinylene) Derivatives 被引量:5
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作者 Jian Ying WANG Yin Kui LI +2 位作者 Wen Xiang HU Sheng Jian TAN Yong Fu LONG (The Centre of Research and Development of Medicine Pharmaceuticals Commission of Science & Technology and Industry for National Defence. Beijing 100101 Materials Engineering and Appl 《Chinese Chemical Letters》 SCIE CAS CSCD 1998年第1期75-77,共3页
A series of soluble poly(p-phenylene vinylene) (PPV) derivatives were synthesized through dehydrochlorination with the p-metaoxy phenol as starting materials. The electronic characteristics of PPV derivatives were stu... A series of soluble poly(p-phenylene vinylene) (PPV) derivatives were synthesized through dehydrochlorination with the p-metaoxy phenol as starting materials. The electronic characteristics of PPV derivatives were studied. 展开更多
关键词 poly(p-phenylene vinylene) DEHYDROCHLORINATION electronic characteristic
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PBO/PIPD纳米纤维复合薄膜的制备及性能研究 被引量:1
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作者 吴飞舟 邱国栋 +8 位作者 王斌 范新年 向东 周万立 武元鹏 赵春霞 李辉 付兴伟 李云涛 《塑料工业》 CAS CSCD 北大核心 2023年第5期175-180,186,共7页
通过在聚对苯撑苯并二噁唑(PBO)纳米纤维基体中引入聚(2,5-二羟基-1,4-苯撑吡啶并二咪唑)(PIPD)纤维制备了PBO/PIPD纳米纤维复合薄膜,并利用Cu^(2+)的络合作用协同增强PBO/PIPD纳米纤维复合薄膜的交联结构。对所制备的PBO/PIPD纳米纤维... 通过在聚对苯撑苯并二噁唑(PBO)纳米纤维基体中引入聚(2,5-二羟基-1,4-苯撑吡啶并二咪唑)(PIPD)纤维制备了PBO/PIPD纳米纤维复合薄膜,并利用Cu^(2+)的络合作用协同增强PBO/PIPD纳米纤维复合薄膜的交联结构。对所制备的PBO/PIPD纳米纤维复合薄膜进行了微观结构的表征以证实其3D网状交联结构,并对PBO/PIPD纳米纤维复合薄膜的结构与组成进行了研究。研究了不同金属离子和不同质量分数PIPD纤维对PBO/PIPD纳米纤维复合薄膜力学性能的影响。结果表明,相比于原始PBO纳米纤维薄膜,本文所制备的PBO/PIPD纳米纤维复合薄膜具有优异的力学性能。其拉伸强度提高了2.4倍达到100.99 MPa,断裂伸长率提高了8.5倍达到10.5%。 展开更多
关键词 聚对苯撑苯并二噁唑纳米纤维 聚(2 5-二羟基-1 4-苯撑吡啶并二咪唑)纤维 纳米纤维复合薄膜 络合作用
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NOVEL SYNTHESIS OF POLYARYLENESULFONIUM CATIONS THROUGH A MULTI-ELECTRON TRANSFER PROCESS
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作者 TSUCHIDA Eishun MIYATAKE Kenji 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1998年第2期106-116,共11页
The oxidative polymerization of aryl sulfoxides provides a novel polysulfo-nium compound, poly(methylsulfonio-1,4-phenylenethio-1,4-phenylene cation) in quantita-tive yield. The polymerization proceeds efficiently in ... The oxidative polymerization of aryl sulfoxides provides a novel polysulfo-nium compound, poly(methylsulfonio-1,4-phenylenethio-1,4-phenylene cation) in quantita-tive yield. The polymerization proceeds efficiently in an acidic solution under atmosphericconditions. Oxygen, chemical and electrochemical oxidations are available. Vanadyl acety-lacetonate and cerium ammonium nitrate act as an effective catalyst for the oxygen ox-idative polymerization. The polymerization mechanism involves multielectron oxidation ofthe sulfides followed by successive electrophilic substitution. The resulting polyarylenesul-fonium cations are useful as a soluble precursor for the synthesis of high molecular weight(M_w>10~5) poly(thio arylne)s. 展开更多
关键词 Oxidative polymerization Multi-electron transfer Sulfonium cation poly(thio phenylene)
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日光老化及海水老化对PPTA纤维结构及性能的影响
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作者 赵开荣 李娜 +3 位作者 周欣伊 于俊荣 张浩 王彦 《合成纤维工业》 CAS 2023年第5期10-16,共7页
通过日光老化、海水老化及日光/海水复合老化实验,研究了不同老化方式及老化时间对聚对苯二甲酰对苯二胺(PPTA)纤维表面形貌、化学结构、结晶结构及力学性能的影响。结果表明:随日光老化时间延长,PPTA纤维表面逐渐劣化,分子链中酰胺键... 通过日光老化、海水老化及日光/海水复合老化实验,研究了不同老化方式及老化时间对聚对苯二甲酰对苯二胺(PPTA)纤维表面形貌、化学结构、结晶结构及力学性能的影响。结果表明:随日光老化时间延长,PPTA纤维表面逐渐劣化,分子链中酰胺键发生断裂,结晶度和晶粒尺寸下降,结晶结构被破坏,力学性能呈现先慢后快的下降趋势,日光老化35 d后PPTA纤维的断裂强度和断裂伸长率保留率分别为73.7%和69.2%;海水老化35 d后PPTA纤维表面产生深度较浅的纵向沟壑,大部分集中在纤维皮层;复合老化35 d后PPTA纤维表面纵向沟壑较日光老化35 d时更深,逐渐向PPTA纤维芯层深入;海水老化35 d后纤维的断裂强度和断裂伸长率保留率分别为63.0%和72.4%,日光/海水复合老化35 d后纤维断裂强度和断裂伸长率保留率分别为58.7%和65.9%。 展开更多
关键词 聚对苯二甲酰对苯二胺纤维 日光老化 海水老化 结构 性能
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热拉伸处理温度对PPTA纤维结晶和力学性能的影响
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作者 孙潜 孔海娟 王斯民 《合成纤维工业》 CAS 2023年第1期26-29,共4页
为提高国产聚对苯二甲酰对苯二胺(PPTA)纤维的拉伸模量,采用热拉伸法在不同温度下对PPTA纤维进行处理,利用纤维强伸度仪、乌氏黏度计、X射线散射仪对纤维进行测试,研究热拉伸处理温度对纤维结晶性能和力学性能的影响。结果表明:随着热... 为提高国产聚对苯二甲酰对苯二胺(PPTA)纤维的拉伸模量,采用热拉伸法在不同温度下对PPTA纤维进行处理,利用纤维强伸度仪、乌氏黏度计、X射线散射仪对纤维进行测试,研究热拉伸处理温度对纤维结晶性能和力学性能的影响。结果表明:随着热处理温度的升高,PPTA纤维的拉伸强度降低,模量先增大后减小,在440~480℃时综合力学性能较好;PPTA纤维的结晶度与模量变化趋势相似,在拉伸温度为500℃时结晶度最大为74.0%;与未处理PPTA纤维相比,热拉伸处理后纤维的晶粒尺寸增大,取向度提高;比浓对数黏度与拉伸强度的变化趋势一致,随着热处理温度的升高而降低。 展开更多
关键词 聚对苯二甲酰对苯二胺纤维 热拉伸处理 力学性能 结晶性能
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STUDIES ON THE POLYPYRROLE/POLYELECTROLYTE MOLECULAR COMPOSITES
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作者 宝净生 徐朝俦 蔡玮 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1993年第2期178-184,共7页
The potyelectrolyte of propane sulfonate(PS) grafted PPTA copolymers——PPTA-PS, PPTA[O]-PS, PPTA[C]-PS were prepared and used as electrolyte in the process of electrochemical polymerization of pyrrole to form the mol... The potyelectrolyte of propane sulfonate(PS) grafted PPTA copolymers——PPTA-PS, PPTA[O]-PS, PPTA[C]-PS were prepared and used as electrolyte in the process of electrochemical polymerization of pyrrole to form the molecular composite polypyrrole (PPY)/Polyelectrolyte.The preparation and liquid crystalline property of three kinds of polyelectrolyte, the electrical conductivity, mechanical properties, SEM and thermoproperties of PPY/polyelectrolyte are presented in detail. 展开更多
关键词 poiypyrrole poly(p-phenylene terephthalamide) polyELECTROLYTE Conductive composite
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CONFORMATION AND CHAIN PACKING STRUCTURES OF POLY (ρ-PHENYLEN BENZOBISTHIAZOLE) BY MOLECULAR SIMULATION
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作者 杨小震 刘跃 徐晓林 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1997年第4期295-304,共10页
The conformation, the chain packing stabilization and the unit cell modeling of poly(p-phenylene benzobisthiazole) have been investigated by using molecular simulation techniquein the present work. A coupling behaviou... The conformation, the chain packing stabilization and the unit cell modeling of poly(p-phenylene benzobisthiazole) have been investigated by using molecular simulation techniquein the present work. A coupling behaviour of σ-bond rotations at either side of the pheny-lene ring or the heterocyclic ring was found surely to exceed a length of the repeat unit ofthe polymer chain. For a single chain model, the stable torsion angle of the repeat resultedat 14°. In the crystalline cell minimization, the dihedral angle along the polymer chaincould even be stabilized in various values. It therefore indicates that the intermolecularinteraction does play a considerable role for this polymer forming the conformation. Ac-cording to cohesive energies calculated for these unit cell models, the torsion angle in themost stable crystalline cell is 0°. When the chains packing together, there exist so manyenergy stable wells along the chain axis 0.35--0.36nm apart from neighbouring chains.Most of the unit cells have quite closed cohesive energies. These factors thus cause thedifficulty of forming an unique perfect crystalline structure of the polymer. The presentstudy suggested a number of reasonable unit cells, and the most stable crystalline structurefor this polymer that is monoclinic, non-primitive unit cell. 展开更多
关键词 poly(p-phenylene benzobisthiazole) Molecular mechanics Crystalline structure Cohesive energy
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A STUDY OF THE MORPHOLOGY OF POLY(1,4 PHENYLEN TEREPHATHALAMIDE) (PPTA) PULP
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作者 王曙中 宣亮 +2 位作者 王文强 肖若鉴 胡家伦 《Journal of China Textile University(English Edition)》 EI CAS 1991年第2期62-67,共6页
The morphology of PPTA pulp is investigated by means of optical microscope and scanningelectron microscope (SEM). It shows that PPTA pulp has feather-like branch, needle point-likeend, and irregular cross-section, whi... The morphology of PPTA pulp is investigated by means of optical microscope and scanningelectron microscope (SEM). It shows that PPTA pulp has feather-like branch, needle point-likeend, and irregular cross-section, which are very important for PPTA pulp as a reinforcer. Theseparation limitation of PPTA pulp is also investigated from both torn and brittle break cross-sec-tion. A packing mechanism is proposed to illustrate the microfibril packing in the gel system. 展开更多
关键词 poly-p-phenylene terephthal AMIDE fibre filling material fibreillion MORpHOLOGY ppTA-pulp
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