【作者】 刘鹏涛；

【导师】 蹇锡高； 王锦艳；

【作者基本信息】 大连理工大学 ， 材料学， 2006， 博士

【摘要】 聚芳酰胺是一类重要的特种工程塑料，具有优异的耐高温性能、力学性能和绝缘性能，广泛应用在航天、电子、现代通讯等尖端领域。但是商品化的聚芳酰胺如聚对苯二甲酰对苯二胺（PPTA）即使加热到分解温度也不熔融，也不溶于普通溶剂，Kevlar^?只能通过PPTA的浓硫酸溶液纺丝成型，条件苛刻，成本昂贵。研究开发综合性能优异且可溶于有机溶剂的新型聚芳酰胺，可通过聚合原液直纺制备高性能纤维，是科学界和工业界都十分关注的热点。本文将二氮杂萘酮结构以及柔性的醚键引入到聚合物主链之中，在保持聚合物优异综合性能的前提下，改善了聚合物的溶解性能，得到了可以进行聚合原液直纺的聚芳酰胺。具体研究内容如下： 以三种含二氮杂萘酮结构的二元羧酸单体与对苯二甲酸和几种商品二胺以Yamazaki膦酰化法进行三元共缩聚反应，制备了3个系列聚芳酰胺PAⅠ～Ⅲ，对其结构进行了表征，考察了聚合物的分子链形态、溶解性、热性能以及薄膜的拉伸性能和亲水性，总结了二氮杂萘酮结构的比例以及二胺的结构对各种性能的影响规律。随着聚合物主链中二氮杂萘酮结构比例的增加，聚合物逐渐趋近于无定型态，溶解性得到改善，热性能变化不明显。聚合物薄膜拉伸性能优异，拉伸强度最高可以达到244MPa。 将含二氮杂萘酮结构的二胺引入到聚对苯二甲酰对苯二胺主链中，采用低温溶液聚合法，制备了一系列新型三元溶致液晶聚芳酰胺树脂P1。该类共聚物具有中等特性粘度，WAXD测试表明聚合物为无定型态；在NMP或NMP／1％LiCl中具有良好的溶解性能，并且具有良好的耐热性能，其玻璃化转变温度T_g在312～351℃之间，10％热失重温度T_d（10％）在513～538℃之间，大部分聚合物可在NMP／1％LiCl和DMAc／1％LiCl中形成溶致液晶态，部分共聚物甚至可以在纯NMP中产生溶致液晶态。三元聚芳酰胺树脂P1采用分步加料与混合加料得到的聚合物在特性粘度、玻璃化转变温度、溶解性以及液晶溶液的临界浓度等方面存在一定的差异。 以含二氮杂萘酮结构的二胺、4，4’-二氨基二苯醚、对苯二胺和对苯二甲酰氯为单体，合成了一系列新型四元聚芳酰胺树脂P2。优化了聚合反应中单体浓度、单体比例、酸吸收剂用量、助溶剂用量、反应温度、时间等工艺条件，得到的聚合物特性粘度最高可达5.3dL／g（NMP／1％LiCl，25℃）。WAXD测试表明聚合物为半结晶态，随着二氮杂萘酮结构和醚键比例的增加，聚合物溶解性逐渐得到改善；聚合物耐热等级与商品聚芳酰胺相当。聚合物原液直纺初步实验得到的纤维的拉伸性能与Kevlar^?相当，超过2.8GPa。同一共聚物在不同的溶剂中临界浓度不同，随着溶剂与聚合物之间作用力的减弱，临界浓度逐渐减小。更多还原

【Abstract】 Aromatic polyamides are a class of high-performance polymers and they are widely used in various fields due to their high thermal stability and good mechanical properties. However, high rigidity of the backbone and strong hydrogen bonding interchains result in their insolubility in most organic solvents and also give rise to their high softening temperatures. These properties make them generally difficult and expensive to process. For example, Kevlar?, which structure is poly（p-phenylene terephthalamide）, can only be spinned from its conc. H₂SO₄ solution. In order to improve the solubility while maintaining the excellent properties, phthalazinone moieties and ether linkages were introduced into the polymer main chain. Thus novel fiber could be spinned directly from their polymer solutions.Three series of novel aromatic copolyamides PA I III were synthesized from three different phthalazinone-containing diacids, terephthalic acid and some commercial diamines by Yamazaki polycondensation method. Their structures were characterized by FT IR and ¹H NMR. The effect of the ratios of phthalazinone moieties and the structure of diamines on the polymers’ morphology, solubility and thermal properties was systemicly studied. Some films of the polyamides were obtained by casting from their NMP solutions and showed good mechanical properties.The copolyamides P1 were prepared from l,2-dihydro-2-（4-aminophenyl）-4-[4-（4-（aminophenoxyl）phenyl）]phthalazin-l-one （DHPZ-DA）, p-phenylenediamine （PPD） and terephthaloyl dichloride （TPC） by low temperature solution polycondensation method. The polymers had middle inherent viscosities of 1.21-3.57 dL/g. The introduction of phthalazinone moieties and ether linkages into the main chain improved their solubility in some polar aprotic solvents. The glass transition temperatures （7_gs） were all above 310℃ and the 10% weight loss temperatures were higher than 500°C. WAXD measures indicated that these polyamides were amorphous. Most of these polyamides formed anisotropic phase in their conc. H₂SO₄, NMP （lwt% LiCl） and DMAc （lwt% LiCl） solutions. In addition, some difference in the inherent viscosity, T_g, solubility and critical concentration （C*） values were observed by changing adding manner of the monomers.The copolyamides P2 were prepared from DHPZ-DA, PPD, 4,4’-diaminodiphenylether and TPC. With some well designed experiments, all the factors which may affect the polycondensation, including reaction temperature, monomer concentration, acid receptor concentration, salt concentration and so on, were tested, and the optimized factors were found.更多还原