甲基丙烯酰氯改性木质素对甲酚共混聚乳酸制备复合膜的研究

Research on Preparing Composite Film by Using Methyl Acryloyl Chloride Modified Lignocresol and Polylactic Acid

为提高木质素对甲酚与聚乳酸(PLA)复合时的界面相容性,进而提高材料的力学性能,利用甲基丙烯酰氯对木质素对甲酚进行接枝改性,然后将改性前后的木质素对甲酚分别与PLA共混制备复合膜,分析了改性前后木质素对甲酚的分子结构及复合膜的力学性能。结果表明,甲基丙烯酰基可成功接枝到木质素对甲酚上,其对木质素对甲酚的用量为0.5 m L/0.5 g、改性次数为4次时,木质素对甲酚的改性效果最佳。随改性木质素对甲酚添加量的增加,复合膜拉伸强度虽逐渐下降,但下降的程度低于添加未改性木质素对甲酚的复合膜;改性木质素对甲酚与PLA形成的复合膜的断裂伸长率远高于纯PLA膜的断裂伸长率,且随改性木质素对甲酚添加量的增加,复合膜的断裂伸长率呈先升高后平稳的趋势;综合考虑复合膜的拉伸强度和断裂伸长率,改性木质素对甲酚的最佳添加量为10%。

In order to improve the interfacial compatibility of lignocresol and polylactic acid which were used to prepare a composite film,methyl acryloyl chloride was used to modify lignocresol. The improvement of the interface compatibility could improve the mechanical properties of the composite film. The molecular structures of lignocresol and modified lignocresol were analyzed and the mechanical properties of the composite film were tested. The results indicated that methyl acryloyl was successfully grafted onto lignocresol. When the dosage of methacryloyl chloride to lignocresol was 0. 5 m L/0. 5 g,the result of four times modification was the best. With the increase of the amount of modified lignocresol,the tensile strength of the composite film decreased gradually,but the decrease extent was lower than that of the unmodified lignocresol. The elongation at break of the composite film made with modified lignocresol was much higher than PLA film. With the increase of the amount of modified lignocresol,the elongation at break of composite film increased at first and then was leveling off. Considering the tensile strength and the elongation at break of the composite film,the optimum amount of modified lignocresol was 10%.