不同光敏剂对LDPE薄膜光降解影响比较

合成硬脂酸铁（FeSt3）、硬脂酸铈（CeSt4）和硬脂酸锰（MnSt2），用母粒法制备了可光降解LDPE薄膜。采用傅立叶红外变换光谱仪、万能材料试验机和乌氏粘度计测定羰基指数、断裂伸长率、拉伸强度和分子量，研究了这3种光敏剂及其用量对LDPE降解程度的影响。结果表明，3种光敏剂的光敏活性FeSt3〉CeSt4〉MnSt2；LDPE的光降解程度并非随着光敏剂含量的增加而增大，在控制用量的情况下。MnSt2更适合用作稳定剂；光降解使链结构发生了变化。分子量降低。

Photo-degradation of disposable polyethylene films

Photodegradable polyethylene films containing FeSt_3,CeSt_4 and MnSt_2 as photosensitizes are prepared by master batch.The effect of the three photosensitizes and their quantity on the carbonyl index,elongation,tensile strength and molecular weight are measured by means of FT-IR,mechanical measurement and viscidity.The results show that the activities of the three photosensitizes are as follows:FeSt_3>CeSt_4>MnSt_2.The degree of photo degradation of LDPE is not enhanced with the increase of photosensitizes.The MnSt_2 could act as stabilizer.Meanwhile,the structure of the polyethylene films changes under the UV and molecular weight decreases.