聚对苯二甲酰对苯二胺对尼龙-6共混改性的影响

<正> 聚对苯二甲酰对苯二胺(PPTA)是一种棒状的刚性高分子,由它的液晶溶液可制得高强度、高模量、耐高温纤维,这种纤维可作为增强剂以制备高性能的复合材料。若将刚性链高分子以近于分子水平分散到柔性链高分子中,可期望得到性能良好的分子复合材     

改性芳纶/聚苯胺复合导电纤维的制备

以聚对苯二甲酰对苯二胺(简称芳纶,PPTA)纤维为基材,使用环氧氯丙烷(ECP)对PPTA表面进行有机修饰,得到了ECP改性的PPTA纤维(ECP-PPTA),然后使苯胺单体在ECPPPTA表面接枝聚合,制备了ECP-PPTA/PANI复合导电纤维。用傅里叶变换红外分光光度计(FT-IR)、扫描电子显微镜(SEM)、热重分析仪(TGA)及X射线衍射分析仪(XRD)等分析测试方法对ECP-PPTA及ECP-PPTA/PANI复合导电纤维进行了表征。结果表明:PPTA经ECP改性后,PANI成功接枝在PPTA表面,制备的ECP-PPTA/PANI复合导电纤维的电阻率低于PPTA/PANI纤维的,其室温电阻率最低为0.32MΩ·m。     

聚对苯二甲酰对苯二胺在硫酸液晶态溶液中的降解

由聚对苯二甲酰对苯二胺(简称 PPTA)纺制的高强度、高模量、耐高温有机纤维,只有当 PPTA 具有足够高的分子量时,才能显示出优异的物理化学性能。杜邦公司的 T.I.Bair 和 P.W.Morgan 等曾报道了 PPTA 在 HMPA,NMP 和 DMAC 等酰胺溶剂与氯化锂体系中的溶解状况,室温时为5.82及7.95%,溶解度较低。PPTA 在硫酸等强酸中,虽有较     

对苯二甲酰氯与N-甲基吡咯烷酮反应机理以及对聚对苯二甲酰对苯二胺聚合的影响

稳定合成高分子量聚对苯二甲酰对苯二胺(PPTA)树脂是生产高性能芳纶纤维的基础.在PPTA聚合过程中,以单体对苯二甲酰氯(TPC)/N-甲基吡咯烷酮(NMP)溶液与单体对苯二胺(PPD)/NMP溶液进行溶液缩聚反应是最理想高效的方式,但是因为TPC/NMP间未知的相互作用导致这种聚合方式难以实现.通过实验与计算模拟相结合的方式,利用红外光谱(FTIR)、核磁共振(1H NMR)、飞行时间质谱及示差扫描量热分析对TPC/NMP间的反应进行了分析,并通过分子模拟计算证明TPC与NMP会发生类似Vilsmeier-Haack反应,导致TPC上的酰氯基团失活,从而严重影响其聚合反应活性.最后,通过PPTA聚合实验验证了该结论的正确性.     

吡咯在一些聚合物基质中聚合生成导电高分子复合物的研究

用电化学氧化聚合方法将吡咯在聚氨酯(PU)、聚已内酰胺(Nylon 6)、聚芳砜酰胺(PSu)及聚对苯二甲酰对苯二胺(PPTA)等绝缘聚合物中聚合生成聚吡咯(PP_y)的高分子复合物PU/PP_y、Nylon 6/PP_y、PS_u/PP_y、PPTA/PP_y等。它们具有良好的电导率及力学性能、报导了他们的制备方法及电导率、力学性能、电化学活性、扫描电镜、X-射线衍射的表征。     

含有烷基取代基的热致液晶性全芳香共聚酯的合成

<正> 聚对苯二甲酸对苯二酚酯具有类似于聚对苯二甲酰对苯二胺的刚性棒状分子结构,其分子的相关长度甚至还大大超过后者,这就使得有可能由此聚合物纺制出高强度的纤维。遗憾的是,聚对苯二甲酸对苯二酚酯的熔点太高,又尚未找到能使它溶解从而制     

凝胶渗透色谱测定聚对苯二甲酰对苯二胺的分子量分布

<正> 聚对苯二甲酰对苯二胺(PPTA)是一种刚性棒状高分子,一般仅溶于浓硫酸,氢氟酸等强酸溶剂。凝胶渗透色谱(GPC)测定PPTA分子量分布,国内外报道不多。Schaefgan等报道了在DMA-4Wt.％LiCl中测定的PPTA分子量分布图谱,但溶剂和具体测试方法未作介绍。Arpin等用96％硫酸作溶剂,在简易GPC装置上进行了测定。国内赵择卿等采用与Arpin相同的方法进行了测试,本文采用混合有机溶剂溶解PPTA,以DMA-3Wt.％LiCl作淋洗液,在HITACH 635-TR HPLC仪GPC附件上,用50厘米长、内径8毫米的分析柱,紫外吸收检测(波长λ=330nm),室温条件下测定了     

基于基团贡献法和分子动力学预测聚间苯二甲酰对苯二胺的玻璃化转变温度

采用基团贡献法(GC)和分子动力学法(MD)模拟了聚间苯二甲酰间苯二胺纤维(MPDI)和聚对苯二甲酰对苯二胺(PPTA)的玻璃化转变温度, 并与实验值进行了对比. 结果表明, 使用基团贡献法和分子动力学法测得的MPDI和PPTA的玻璃化转变温度与实验值接近, 说明基团贡献法和分子动力学法可以用来预测芳香族聚酰胺的玻璃化转变温度. 在此基础上, 采用GC和MD预测了聚间苯二甲酰对苯二胺(PPIA)的玻璃化转变温度. 在MD模拟中, 对密度、 比体积、 回转半径和非键相互作用随温度的变化规律进行了分析. 结果表明, 自由体积理论能较好地解释PPIA的玻璃化转变现象, 其中非键相互作用随温度的变化是玻璃化转变的本质原因. PPIA的玻璃化转变温度介于MPDI和PPTA之间, 有望成为综合性能介于两者之间的另一种高性能聚酰胺.     

烷基取代聚对苯二甲酰对苯二胺的相对分子质量以及相对分子质量分布分析北大核心CSCD

聚对苯二甲酰对苯二胺(PPTA)的相对分子质量和相对分子质量分布直接影响芳纶纺丝性能。PPTA主链间的氢键作用使其难溶于氯仿等常用有机溶剂中,不能满足核磁共振波谱仪、质谱和凝胶渗透色谱法等测试要求。为了提高PPTA的溶解性,通过主链上N位接枝系列不同种类和取代程度的烷基侧链,得到可溶解的烷基化PPTA,考察了不同烷基种类和烷基化条件对相对分子质量以及相对分子质量分布的影响。乙基烷基化PPTA的取代程度可达98.6%,有利于得到多分散系数较低和更为准确的相对分子质量分布。根据马克霍温克方程,得到了特定黏度范围内重均相对分子质量与特性黏数的关系公式为[η]=9.96×10^(-3)M_(w)^(1.08),对优化PPTA合成条件和改善芳纶纤维的性能提供了参考。     

主链含有氯代亚苯基的芳香族聚酰胺

<正> 芳香族聚酰胺具有优良的机械和热性能,是近二十年来比较重视的研究领域。对于刚性链的芳香族聚酰胺,如聚对苯二甲酰对苯二胺(PPTA),它们只能溶解在硫酸一类的强极性溶剂里,因此进行了许多向分子链上引入取代侧基的改性研究,清造刚等将含卤素取代基的对苯二甲酸和一系列芳香族二胺进行均聚和共聚,改变了聚合物的熔点、结晶性和溶解性,本文报道由苯环上含氯原子的二胺和对苯二甲酰氯合成了含氯原子侧     

在酰胺-盐溶剂体系中对苯二甲酰氯与对苯二胺的缩聚反应

本文研究了在酰胺-盐溶剂体系中对苯二胺与对苯二甲酰氯的缩聚反应,溶剂对缩聚反应的影响以及溶剂体系与对苯二甲酰氯的副反应。由NMR实验结果表明,聚对苯二甲酰对苯二胺分子中酰胺基团的氢质子由于溶剂化作用向低场方向位移,位移的大小与溶剂的种类及盐的浓度有关。DMAc与NMP两种溶剂体系在缩聚反应过程中皆与对苯二甲酰氟有竞争反应。在该溶剂体系中可得到适于加工成纤的高分子量聚合物。     

Effect of a novel charring agent on thermal degradation and flame retardancy of acrylonitrile–butadiene–styrene

A novel charring agent poly(p-propane terephthalamide) (PPTA) was synthesized by using terephthaloyl chloride and 1,3-propanediamine through solution polycondensation and it was used together with ammonium polyphosphate (APP) to prepare a novel intumescent flame retardant (IFR) for ABS. The thermal degradation behaviour and flame retardancy were investigated, the results showed that PPTA could be effective as a charring agent, the flame retardancy of ABS and the mass of residues improved greatly with the addition of IFR. When the content of APP was 22.5 mass% and PPTA was 7.5 mass%, the limiting oxygen index (LOI) value of IFR-ABS system was found to be 32.4, and class V-0 of UL-94 test was passed. Moreover, the synergistic effects of two different adjuvants AlPi and MnO₂ in IFR-ABS system have been studied.     

Non-aqueous Suspension Polycondensation in NMP-Ca Cl_2/Paraffin System―A New Approach for the Preparation of Poly(p-phenylene terephthalamide)

A non-aqueous suspension polycondensation method was proposed to proceed the reaction of p-phenylenediamine and terephthaloyl chloride for the preparation of poly(p-phenylene terephthalamide)(PPTA). The system was operated with NMP-Ca Cl2 solution as the dispersed phase and inert liquid paraffin as the continuous phase. Each of NMP-Ca Cl2 solution microdroplet suspended in paraffin served as a microreactor where the polycondensation took place. According to the results of TGA, XRD, IR, SEM and EA, PPTA with good quality was obtained through this novel method, and a number of main factors influencing this process were investigated to determine the optimum condition for the preparation of PPTA. Besides, this two-phase polycondensation system brings many unique advantages compared to the conventional solution polycondensation method, including a sealed reaction environment keeping the reactants away from oxygen and water, easy removal of HCl to promote the reaction, well-controlled temperature and low viscosity which means less energy cost.     

添加氢化钙合成高分子量聚对苯二甲酰对苯二胺的研究

研究使用氢化钙代替吡啶作为酸吸收剂合成高分子量聚对苯二甲酰对苯二胺(PPTA),并与以吡啶作酸吸收剂的聚合产物进行对比以评估该研究的应用前景.尝试以氢化钙代替吡啶,考察氢化钙的加入对TPC与PPD的聚合过程及聚合产物分子量和结构的影响.研究结果表明,添加氢化钙可以聚合出高分子量PPTA.元素分析、X-射线衍射及红外光谱分析结果表明,使用氢化钙和吡啶作为酸吸收剂合成的PPTA在元素含量和结构上均相同.热重分析结果表明,使用两种酸吸收剂得到的PPTA的热分解温度都在550℃左右.这些研究结果初步证明使用氢化钙代替吡啶进行高分子量PPTA工业聚合是可行的.     

聚酰胺——聚对苯二甲酰对苯二胺的研究

详细地研究了对苯二甲酰-对苯二胺低温溶液缩聚时,各种反应条件对聚合体分子量的影响,获得了适合于液晶纺丝的高分子量聚合体,其η_(inh)可达5—7。结果表明,聚合体系的水份、单体克分子浓度、各种混合溶剂体系比对聚合体分子量有明显的影响。为获得高分子量聚合体,混合溶剂体系的最佳组成分别为:HMPA:DMAC=4:1(体积比)、HMPA:NMP=7:3 和 HMPA:THF=9:1。当水份含量大于100ppm时,将严重妨碍高分子量聚合体的得到。在缩聚反应初期,聚合体η_(inh)随时间迅速增长,两三分钟内出现凝聚现象,聚合转化率达100％。体系凝聚后缩聚反应仍然进行,聚合体仍有增长。     

Molecular layer deposition of poly(p-phenylene terephthalamide) films using terephthaloyl chloride and p-phenylenediamine

Ultrathin polymer films can be fabricated using the gas-phase method known as molecular layer deposition. This process typically uses bifunctional monomers in a sequential, self-limiting reaction sequence to grow conformal polymer films with molecular layer control. In this study, terephthaloyl chloride (TC) and p-phenylenediamine (PD) were used as the bifunctional monomers to deposit poly(p-phenylene terephthalamide) (PPTA) thin films. 3-Aminopropyl trimethoxysilane or ethanolamine was used to prepare amine-terminated surfaces prior to the PPTA MLD. The surface chemistry and growth rate during PPTA MLD at 145 degrees C were studied using in situ transmission Fourier transform infrared (FTIR) spectroscopy experiments on high surface area powders of SiO2 particles. PPTA MLD thin film growth at 145 degrees C was also examined using in situ transmission FTIR experiments on flat KBr substrates with an amine-terminated Al2O3 ALD overlayer. The integrated absorbances of the N-H and amide I stretching vibrations were measured and used to estimate the thin film thickness. X-ray reflectivity (XRR) experiments were also employed to measure the film thickness after PPTA MLD at 145 degrees C and 180 degrees C. The experiments revealed that the TC and PD reactions displayed self-limiting surface chemistry. The surface species alternated with sequential TC and PD exposures and the PPTA MLD films grew continuously. However, the growth rates per MLD cycle at 145 degrees C were less than expectations based on the size of the molecules involved in the reaction chemistry and were variable between 0.5 and 4.0 A per TC/PD reaction cycle. The lower growth rates are explained by the growth of a limited number of polymer chains on the substrate. The variability in the growth rate is attributed to the difficulties with the bifunctional monomer precursors. Alternative surface chemistries for polymer MLD are proposed that would avoid the use of bifunctional monomers.     

Polymerization and decomposition of terephthaloyl chloride and p-phenylenediamine at 500 °C

In order to synthesize the high temperature solid lubricating film by gas-phase polymerization at 500?°C with two kinds of gasified monomers for use in airplane and rocket engines, the polymerizing activity of terephthaloyl chloride (TPC) and p-phenylenediamine (PPD) at 500?°C and their polymerized product poly-p-phenyleneterephthamide (PPTA) as well as its decomposed solid residues were researched. It was proved by FT-IR and ¹HNMR on the solid residues after the 10?min experiment of the both monomers in muffle furnace at 500?°C and PPTA synthesized by conventional method that at 500?°C the polymerization tendency of these monomers should trump their decomposition tendency. The solid residues after the 10?min experiment mainly consisted of polymerized products which would decline as the experimental period increases, while the content of decomposed and carbonized products would raise. FT-IR and elemental analysis revealed a similar structure of the solid residues after the both monomers or PPTA calcined for 60?min at 500?°C, which further demonstrated the polymerized products would degrade, decompose and carbonize after the prophase polymerization. Finally, effects of experimental temperature and monomers molar ratio on amounts and structures of the solid residues were discussed to propose preliminary mechanisms of polymerization and decomposition.     

THE POLYCONDENSATION OF TEREPHTHALOYL CHLORIDE AND p-PHENYLENEDIAMINE HYDROCHLORIDE IN NMP-CaCl_2 SOLVENT SYSTEM

The solution polycondensation of 1,4-phenylenediamine hydrochloride and terephthaloyl chlo-ride with introducing a tertiary amine in NMP-CaCl_2 solvent system were studied in detail.Effect of reactant concentration, the content of CaCl_2, in NMP solvent and the kinds of tertiary amineon inherent viscosity of PPTA polymer have been studied. High molecular weight PPTA withinherent viscosity over 5 was obtained at 0.35Mol/L of reactant concentration in a solvent of NMP-CaCl_2 with the presence of α-picoline.     

Polyamides from 12-(β-aminoethyl) abietan-18-amine

The 1:1 salt of 12-(β-aminoethyl)abietan-18-amine and adipic acid has been prepared and polymerized. This salt has been copolymerized with the 1:1 salt of hexamethylenediamine and adipic acid. 12-(β-Aminoethyl)abietan-18-amine has been polymerized with isophthaloyl and terephthaloyl chlorides with triethylamine as catalyst and terpolymerized with terephthaloyl chloride and hexamethylenediamine. All polymers have been characterized to some extent, and mechanical properties are reported for two of the polyamide films.