不同牵伸倍率下聚酯复合纤维的微观结构与性能

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2.353.35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。

Microstructure and properties of polyester composite fibers with different drafting ratios

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.