Melt-spun industrial super-strong polycaprolactam fiber: Effects of tie-molecules and crystal transformation
Melt-spun industrial super-strong polycaprolactam fiber: Effects of tie-molecules and crystal transformation
复制标题
熔纺工业超强聚己内酰胺纤维：束缚分子和晶体转变的影响
DOI：
10.1016/j.compositesb.2020.107772
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Meifang Zhu
中科院分区：
文献类型：
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作者：
Jialiang Zhou;Weinan Pan;Hengxue Xiang;Mugaanire Tendo Innocent;Gongxun Zhai;Meifang Zhu
有效改善非晶态区分子取向，调控结晶转变行为，对超高强度聚己内酰胺（HSPA6）纤维的工业化生产具有重要意义。本文系统研究了加入少量高分子量聚己内酰胺（HmwPA）对HSPA6纤维晶体转变、熔体粘弹性、分子取向和力学性能的影响。结果表明：HmwPA提高了HSPA6熔体的弹性模量和损失模量，抑制了拉伸过程中的分子弛豫，形成以α-型为主的晶体结构；因此，HSPA6纤维的拉伸强度和断裂伸长率分别达到10.32 cN/dtex和18.7%。一维和二维广角x射线衍射（WAXD）、小角x射线散射（SAXS）和双折射观察表明，HmwPA不仅抑制了拉伸过程中晶体结构的破坏，而且使非晶区分子取向从63.1%提高到70.1%，同时保持了95%左右的晶体取向。
Effective improvement molecular orientation in the amorphous region and regulating crystallization transformation behavior is of great significance for the industrial production of ultra-strength polycaprolactam (HSPA6) fiber. In this work, the effects of adding a small quantity of high molecular weight polycaprolactam (HmwPA) on the crystal transformation, melt viscoelasticity, molecular orientation and mechanical properties of HSPA6 fibers were systematically investigated. The results indicated that HmwPA increased the elastic modulus and loss modulus of HSPA6 melt and suppressed molecular relaxation during drawing to form a crystal structure dominated by α-form. As such, the tensile strength and elongation at break of HSPA6 fiber reached 10.32 cN/dtex and 18.7%, respectively. 1D and 2D wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS) and birefringence observations demonstrated that the HmwPA not only inhibited the destruction of the crystal structure during fiber drawing but also increased the molecular orientation in the amorphous region from 63.1% to 70.1%, while maintaining the crystal orientation to about 95%.