聚丙烯腈(PAN)溶液是制备高性能碳纤维原丝的纺丝溶液,通过氨化改性PAN溶液进行纺丝,可获得结构均质、致密、性能优良的原丝。在丙烯腈/甲基丙烯酸甲酯/衣康酸(AN/MA/ITA)三元聚合体系中加入不同量氨水,研究不同氨化度对PAN转化率、分子量及分布、黏度和亲水性等的影响。结果表明,当氨化度低于20%时,对PAN转化率和分子量及分布影响较小;当氨化度大于20%时,PAN溶液转化率由91.73%降低至87.2%,重均分子量由28.5×10⁴降低至24.5×10⁴,数均分子量由9.4×10⁴降低至7.6×10⁴,分布系数由2.98升至3.4,对聚合反应进程和原液指标有明显影响。聚会体系加入氨水后,随着氨化度增加,聚合原液旋转黏度和接触角持续降低,原液旋转黏度由11.9×10⁴cP下降至9.8×10⁴cP,接触角由70.1°降低至60.3°,原液亲水性明显改善。

Polyacrylonitrile (PAN) solution is the spinning solution to prepare precursor for carbon fiber.The precursor with homogeneous,compact structure and excellent performance can be obtained by ammoniating of PAN solution.The effects of ammoniation degrees on the conversion,molecular weight and distribution,viscosity and hydrophilicity of PAN were studied by adding different amount of ammonia into the ternary polymerization system with acrylonitrile (AN)/methyl methacrylate (MA)/itaconic acid (ITA).The results shown that when the ammoniation degree was lower than 20%,It had little effect on the conversion,molecular weight and distribution of PAN.When the ammoniation degree was greater than 20%,the conversion was decreased from 91.73% to 87.2%,M_W decreased from 285000 to 245000,M_n decreased from 94000 to 76000,and distribution increased from 2.98 to 3.4.However,with the increase of ammoniation degree,the rotational viscosity and contact angle of the polymerization solution decreased continuously.The rotational viscosity of PAN solution decreased from 119000 to 98000cP,and the contact angle of PAN solution decreased from 70.1° to 60.3°.The hydrophilicity of PAN solution changed obviously.