不同牵伸倍率下聚酯复合纤维的微观结构与性能

Microstructure and properties of polyester composite fibers with different drafting ratios

为研究聚对苯二甲酸乙二醇酯/聚对苯二甲酸丙二醇酯(PET/PTT)并列型复合纤维制备工艺与其结构及性能之间的关系,借助二维广角X射线衍射仪、差示扫描量热仪等对未牵伸以及2.35~3.35倍牵伸纤维的结晶取向性能、热性能、力学性能以及卷曲性能进行测试与分析。结果表明:随着牵伸倍率的增加,PET/PTT复合纤维内部单组分结晶度变化有所差异,PET组分结晶度由43.04%增至45.73%,但PTT组分的结晶度几乎不变,其取向度由82.3%增大至89.2%,然后保持稳定,说明牵伸诱导取向达到饱和;同时,取向度的增大也导致PET/PTT复合纤维的弹性模量由16.8 cN/dtex增加到23.1 cN/dtex,断裂强度由2.9 cN/dtex增加到3.5 cN/dtex,但断裂伸长率由52.6%下降到38.6%;牵伸倍率的增加导致双组分纤维结构差异明显,使复合纤维的卷曲性能更加优异。

In order to study the relationship between process,structure and properties of PET/PTT parallel composite fibers,the crystalline orientation properties,thermal properties,mechanical properties and crimp properties,unstretched and 2.35-3.35 times stretched elastic fibers were tested and analyzed with the two-dimensional wide angle X-ray diffractometer and differential scanning calorimeter.The crystallinity of the PET/PTT composite fiber increased from 43.04%to 45.73%,but the crystallinity of the PTT fiber remained stable,its orientation increased from 82.3%to 89.2%,indicating that the draft induction orientation reached saturation.The increase in orientation also led to the increase of the elastic modulus of PET/PTT fiber from 16.8 cN/dtex to 23.1 cN/dtex and the tensile strength from 2.9 cN/dtex to 3.5 cN/dtex,but the elongation at break decreased from 52.6%to 38.6%;the increase of the draft multiplicity led to the obvious difference of the bicomponent fiber structure.The increase in draft multiplicity led to a significant difference in the structure of the bicomponent fibers,resulting in more excellent curl properties of the composite fiber.