高模低缩型聚酯工业丝凝聚态结构与应用特性的关联机制

Correlation mechanism between the condensed structure and application characteristics of high modulus low shrinkage polyester industrial fiber

高模低缩(HMLS)型聚酯工业丝的凝聚态结构对其在特定应力和受热条件下应用特性的影响尚不明确。对3种HMLS聚酯工业丝的蠕变、应力松弛、热收缩等性能进行测试,通过广角X射线衍射等方法对其凝聚态结构进行研究,分析结晶度、晶区和非晶区取向以及晶粒尺寸等参数与HMLS聚酯工业丝应用特性的关联性。结果表明,结晶度和非晶区取向度的协同作用对HMLS聚酯工业丝的蠕变、应力松弛和热收缩性能有重要影响。HMLS2的高结晶度抑制了应力作用和热收缩过程中分子链的滑移,适中的非晶区取向度减少了分子链的收缩解取向。HMLS2在60%的平均断裂载荷作用下蠕变回复率高达83.98%,60 s的应力松弛率为14.65%,195℃热处理后强度损失仅为8%,抗蠕变和热稳定性均较好。

The impact of the condensed structure of high modulus low shrinkage(HMLS)polyester industrial fibers on their application characteristics under specific stress and heat conditions is not clear.The creep,stress relaxation and thermal shrinkage properties of three HMLS polyester industrial fibers were tested,and the condensed structure was studied by wide angle X-ray diffraction.The correlation between the application characteristics of HMLS polyester industrial fibers and parameters such as crystallinity,orientation of crystalline and amorphous regions,and grain size was analyzed.The results show that the joint effect of crystallinity and orientation of amorphous region has important influence on creep,stress relaxation and thermal shrinkage of HMLS polyester industrial fiber.The high crystallinity of HMLS2 inhibited the slip of the molecular chain during stress and thermal shrinkage processes,and the moderate orientation of amorphous region also reduced the disorientation of the molecular chain.The creep recovery rate of HMLS2 was 83.98%under 60%average breaking load,the stress relaxation rate was 14.65%treated for 60 s,and the strength loss was only 8%after heat treatment at 195℃,exhibiting good creep resistance and thermal stability.