真空导入成型阴离子聚合尼龙6聚合体系及性能

通过测量不同聚合体系下的阴离子聚合尼龙6(APA-6)反应过程中转化率随时间的变化, 结合真空导入成型的特点, 研究了适合于真空导入成型的APA-6的聚合体系. 研究发现, 己内酰胺钠盐/双酰化内酰胺-1,6-己二胺(C10/C20)(100℃)和己内酰胺钠盐/甲苯二异氰酸酯(C10/TDI)体系反应初期均存在一个转化率线性缓慢增长期, 随后, 聚合体系开始快速反应, 转化率呈指数增长, 反应很快达到平衡. 初步判定这两种体系是适合真空导入成型APA-6复合材料的聚合体系. 在转化率测试的基础上, 利用DSC热分析从活性中心的形成机理进一步分析了C10/TDI体系更适合于较大、 较厚和结构复杂制品的整体成型的原因. 此外, 与普通PA6相比, 真空导入成型APA-6的结晶度、 模量和T_g显著提高, 并且在2种理想体系下聚合的APA-6的性能也有差别, 从活化剂的封端和解封端机理上进行了初步探讨.

Polymerization System and Properties of Anionic Polyamide-6 for Vacuum Infusion Process

To explore the polymerization system suitable for vacuum infusion anionic polyamide-6(APA-6), the conversion-time relations of different activator-initiator combinations for APA-6 were investigated. Accor-ding to the conversion-time relations during the reaction, it indirectly reflected the viscosity-time relations. The results show that the systems of C10/C20(100℃) and C10/TDI are desired for vacuum infusion of anionic polyamide-6 composites, because both of them show slow linear conversion increase at the beginning of the reaction. However, after a while, the polymerization rate increased rapidly and that the degree of conversion increased exponentially in time. On the basis of the previous research, the reason that the systems of C10/TDI was more suitable for manufacturing thicker, lager and more complicated textile fiber reinforced thermoplastic composites were discussed using differential scanning calorimeter(DSC) thermal analysis from the mechanism of the generation of active center. In addition, compared with traditional nylon 6, the degree of crystallinity, modulus and the temperature of glass transition(Tg) of vacuum infusion APA-6 exhibit remarkably improved. And there are also different properties between two kinds of ideal system of anionic polyamide-6 for vacuum infusion process, the reason was preliminary discussed from mechanisms of blocking and de-blocking of the activator.