官能化聚芳酰胺热处理制备聚对苯撑苯并双噁唑的探索研究

It is difficult to synthesize high-performance fiber poly(p-phenylene benzobisoxazole)(PBO) due to difficulties in synthesis of monomer, complicated polymerization reactions and difficult spinning process.The project develops a new method for the preparation of PBO fiber. The project proposes to synthesize PBO precusor firstly using new monomer 4,6-Diamino-1,3-dialkoxybenzene, and secondly PBO fiber by high temperature thermal treatment of PBO precursor fiber after the spinning of the precursor. Studies on the polycondensation of new monomer and terephthaloyl chloride for preparation of the high molecular weight functionalized aromafic polyamide as precursor. Furthermore, this approach will resolve the problem of monomer synthesis and polymerization. The studies on high quality PBO fiber preparation by cyclization reaction of the precursor fiber after its spinning will avoid the difficulties of direct PBO spinning. The project will provide an easier method for the preparation of PBO fibers.

针对高性能纤维聚对苯撑苯并双噁唑（PBO）的现有制备方法中存在的单体合成困难、聚合工艺复杂、纺丝难度大等问题，本项目提出利用新单体4,6-二氨基-1,3-二烷氧基苯合成PBO前躯体，对其先纺丝后再高温热处理实现主链成环的新方法制备目标PBO纤维。该方法通过对新单体与对苯二甲酰氯缩聚反应的研究，制备高分子量的官能化聚芳酰胺前躯体，将解决单体合成困难、聚合工艺复杂的问题；通过对前驱体先纺丝后高温热处理的研究，制备高质量的PBO纤维，将避免直接纺丝难度大等问题。本项目将为简易、高效产业化生产PBO纤维提供理论指导和科学依据。

限制高性能纤维聚对苯撑苯并双噁唑（PBO）应用的最关键因素是其制备难度大，具体体现在单体合成困难，聚合工艺复杂，纺丝难度大等问题，因此本项目旨在探索新方法实现PBO及相应单体的简单、高效、低成本的制备。首先，以4,6-二氨基-1,3-二烷氧基苯取代4,6-二氨基间苯二酚为单体，将其与对苯二甲酰氯缩聚制得 PBO 前躯体-官能化的聚芳酰胺，并将获得的前躯体纺丝后，通过热处理，实现前躯体纤维主链的环化制得噁唑结构的 PBO 纤维，该方法减少了对4,6-二氨基间苯二酚的依赖，显著降低了聚合和纺丝的难度；其次，成功采用非金属的甲磺酸对间苯二酚进行双乙酰化研究，实现一锅法制备出4,6-二氨基间苯二酚单体，极大地缩短了反应时间与步骤，降低了单体合成难度，显著提高了单体的制备效率；第三，通过采用盐单体方法成功制备出噁唑结构PBO共聚物，提高了聚合物的热稳定性等关键性能。