竹纤维/聚乳酸可生物降解复合材料自然降解性能

通过注射成型工艺制备竹纤维/聚乳酸（BF/PLA）可生物降解复合材料。利用X射线衍射（XRD）、凝胶渗透色谱（GPC）、三维视频显微镜及扫描电镜（SEM）等分析手段研究了BF/PLA复合材料自然降解性能。研究结果表明：BF/PLA复合材料自然降解过程中BF首先降解，PLA逐步分层缓慢降解，复合材料质量逐渐减少；PLA分子链上酯基与水反应，分子链不断断裂，结晶度减小，平均分子量降低，分子量分布变窄；复合材料颜色变深，表面变得粗糙不平，部分裸露的BF清晰可见，其拉伸强度和冲击强度逐渐下降。12个月后，BF/PLA复合材料质量损失率达到8.87%，PLA重均分子量降低了25.9%，复合材料的冲击强度和拉伸强度分别降低了44.0%和43.8%。BF/PLA可生物降解复合材料在土壤中的自然降解效率较低。

Natural degradation properties of bamboo fibers/polylactic acid biodegradable composites

Bamboo fibers (BF)/polylactic acid (PLA) biodegradable composites are prepared by injection molding process. The natural degradation properties of BF/PLA composites were studied by the methods of X-ray differaction XRD, gel permeation chromatograph(GPC), 3D video microscope and scanning electron microscope(SEM). The results show that, BF is first degraded in natural degradation of composites, and PLA is degraded stratified, resulting in significant mass loss of composites; ester groups in PLA molecule chain react with water, which fractur molecular chain and declined crystallinity, the average molecular weight of PLA is gradually decreased and the molecular weight distribution narrows; the BF/PLA composites become dark with rough surface, partial nudity BF is visible, and tensile and impact strengths of composites reduce. After 12 month degradation, the mass loss rate of BF/PLA composites reachs 8.87%, the average molecular weight of the PLA in composites is reduced by 25.9%, the impact and tensile strengths of composites are reduced by 44.0% and 43.8% respectively. The natural degradation of BF/PLA biodegradable composites in the soil is relatively slow.