热处理对PLA纤维结晶结构和力学性能的影响

Effect of Heat Treatment on Crystalline Structure and Mechanical Properties of PLA Fibers

通过红外光谱分析、临界溶解时间及力学性能的测定，研究了热处理条件对PLA纤维结晶结构和力学性能的影响。结果表明：干热处理后PLA纤维的相对结晶度提高，处理温度越高相对结晶度越高，同样温度下保持原长处理比松弛热处理的相对结晶度高；90～140℃干热处理不会引起纱线断裂强度的降低，而湿热处理温度高于110℃时PLA纱线的断裂强度和断裂伸长率急剧下降。

The effects of heat treatment conditions on the crystalline structure and mechanical properties of PLA fibers were investigsted through FTIR,CDT analysis and testing the tensile properties. The results of the experiment have shown that the relative crystallinity of PLA fibers was increased after dry-heat treatments; the higher temperature, the larger relative crystallinity. In the same temperature, the relative crystallinity at tension heat treatments was larger than that at loose heat treatments. The breaking strength has not dropped at dry-heat treatments during 90℃to 140℃. But the breaking strength and elongation of PLA yarns have dropped obviously in the wet-heat treatments at the temperature above 110℃.