4,4′-二氨基二苯砜共缩聚改性PPTA及性能研究

Preparation of modified PPTA via copolycondensation with 4,4′-diamino diphenyl sulfone and their performance

芳纶1414(PPTA)以其高强度、高模量、耐化学腐蚀的特性,被广泛应用于航空航天、电器和特种品开发等领域。采用低温溶液缩聚法,在二甲基乙酰胺(DMAC)-氯化锂(LiCl)溶剂体系中引入4,4′-二氨基二苯砜(4,4′-DDS)作为第三单体,对PPTA进行改性。并对改性PPTA进行表征。研究反应温度、LiCl含量以及第三单体含量对共聚物比浓对数黏度的影响。先加入第三单体且添加量为30%(摩尔百分用量),LiCl用量为1.6%(wt,质量分数),第二阶段反应温度为80℃时,制得的改性PPTA比浓对数黏度为2.52mL/g,在氮气气氛下的分解温度为500℃,具有较好的耐高温性能。

Aramid fiber 1414（PPTA） due to its high strength,high modulus,resistance to chemical corrosion prop- erties are widely applied in aerospace, electrical appliances and special product development and other fields. Through low temperature solution polycondensation method, used 4,4＇-diamino diphenyl sulfone （4,4＇-DDS） as the third monomer added in DMAC-LiC1 solvent system to modified PPTA. Utilized FT-IR,TGA and solubility test to characterize the modified PP- TA. The effect of reaction temperature, LiC1 and the third monomer addition on copolymer viscosity was studied. As the third monomer＇s adding amount was 30% （the mole percent usage）, LiCl＇s dosage was 1.6 % （wt, mass fraction）, the second stage reaction temperature was 80℃, then got the inherent viscosity of modified PPTA was 2.52mL/g, the decomposition temperature under nitrogen atmosphere was 500℃,the high temperature resistant performance was showed.