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为改善聚乳酸(polylactic acid,PLA)材料的亲水性,采用电子束辐照接枝亲水性单体N-乙烯基吡咯烷酮对其表面进行改性,得到接枝共聚物PLA-g-PVP。研究了吸收剂用量和反应介质中酸的浓度对PLA接枝率和PLA-g-PVP黏均相对分子质量(简称分子量,下同)的影响,并对PLA-g-PVP的降解性能进行了考察。结果表明,PLA接枝率随着辐照剂量的增加而提高;当反应介质中酸的浓度为0.07 mol/L时PLA-g-PVP的分子量达到极大值;PLA-g-PVP的吸水率和降解速度较PLA明显提高。接枝率为12.1%的PLA-g-PVP共聚物降解48 h后,吸水率为11.5%,是PLA的16.4倍;接枝率为8.8%的PLA-g-PVP共聚物降解168 h后,分子量损失率为82.6%,是PLA的2.4倍。
In order to improve the hydrophilicity of polylactic acid (PLA), the surface of graft copolymer was modified by electron beam irradiation of grafted hydrophilic monomer N-vinylpyrrolidone to obtain PLA-g-PVP . The effects of the amount of absorbent and the concentration of acid in the reaction medium on the graft ratio of PLA and the molecular weight of PLA-g-PVP (molecular weight, the same below) were studied. The degradation performance of PLA-g-PVP Inspected The results showed that the grafting degree of PLA increased with the irradiation dose increasing. The molecular weight of PLA-g-PVP reached the maximum when the concentration of acid in the reaction medium was 0.07 mol / L. The water absorption of PLA-g-PVP And degradation rate was significantly higher than that of PLA. The PLA-g-PVP copolymer with a graft ratio of 12.1% degraded for 48 h and the water absorption was 11.5%, which was 16.4 times that of PLA. PLA-g-PVP copolymer with a graft ratio of 8.8% Molecular weight loss rate of 82.6%, 2.4 times that of PLA.