The PLA materials with improved optical property and derived from renewable resources were synthesized through ring-opening polymerization using natural aloe-emodin, having anthraquinone structure and alcoholic hydroxyl group, as initiator. The chemical bonding of the aloe-emodin unit on PLA backbone provided the PLA with the function of absorbing UV light and would avoid the migration of aloe-emodin during the lifetime of PLA materials. The chemical structure of the new PLA was confirmed by NMR and the content of aloe-emodin was evaluated by UV–Vis absorption spectra. By investigating the structural changes and the variation of average molecular weight (M_n) during the UV-irradiation test, it was found that the aloe-emodin unit could enhance the UV-stability of the polylactide. The molecular weight remained about 80% for aloe-emodin capped PLA after UV irradiation (PLA-E400), while it was only 50% for PLA-C400 without aloe-emodin. A small amount of aloe-emodin could enhance the UV block effect of PLA film. When covered with aloe-emodin functionalized PLA film, the optical damage rate of β-carotene decreased to one-fifth of that for the uncovered one. In addition, aloe-emodin showed little influence on the biodegradation of PLA.

以具有蒽醌结构和醇羟基的天然芦荟大黄素为引发剂，通过开环聚合反应，合成了具有可改善光学性能，可再生资源的PLA材料。芦荟大黄素单元在PLA骨架上的化学键合为PLA提供了吸收紫外线的功能，并避免了PLA生命周期中芦荟大黄素的迁移。新的PLA的化学结构通过NMR确认，芦荟大黄素的含量通过UV-Vis吸收光谱评估。通过研究结构变化和平均分子量（M _n）在紫外线照射试验中，发现芦荟大黄素单元可以增强聚丙交酯的紫外线稳定性。紫外线照射后（PLA-E400），芦荟大黄素封端的PLA的分子量保持约80％，而不含芦荟大黄素的PLA-C400的分子量仅为50％。少量芦荟大黄素可以增强PLA膜的紫外线阻隔效果。当用芦荟大黄素官能化的PLA膜覆盖时，β-胡萝卜素的光学损伤率降至未发现的光学损伤率的五分之一。此外，芦荟大黄素对PLA的生物降解影响很小。