用原子力显微镜研究甲基丙烯酸缩水甘油酯在高密度聚乙烯表面的紫外接枝

利用AFM研究了紫外光引发甲基丙烯酸缩水甘油酯(GMA)在高密度聚乙烯(HDPE)表面接枝初期生成的接枝物的微结构, 对HDPE表面接枝反应的引发速率进行了初步研究. 紫外照射30 s后在HDPE表面形成一些接枝物微粒, 随着照射时间的增加, 微粒越来越多, 其体积也越来越大. 分析结果表明, 每一个接枝物微粒即为一个高度枝化甚至超级枝化的接枝聚合物链. 在30~45 s之间, 接枝密度随照射时间延长几乎呈线性增长; 在45 s后, 接枝密度的增长速度减慢. 在30~45 s之间的引发速度约为6.5 Unit/(μm2·s).

AFM Studies on UV-initiated Grafting of Glycidyl Methacrylate onto High-density Polyethylene Surface

The microstructure of grafted polymer chains has a significant effect on the final properties of the grafted polymer, however, there is still not a direct method to characterize the microstructure of grafted chains. The microstructure of the grafted chains formed in the initial stage of the UV-initiated photografting of glycidyl methacrylate(GMA) onto high-density polyethylene(HDPE) surface and the initiation rate of the surface photografting reaction were studied with tapping mode atomic force microscopy(AFM). The grafted materials with granular structures were found on HDPE surface after 30 s UV irradiation, after that, the number and the volume of the granules increased with the increase of irradiation time. The granule was thought to be a single grafted chain with a highly branched(or superbranched) microstructure. The grafting density on HDPE increased almost linearly with the increase of irradiation time in the range of 30—45 s, and the increasing rate of grafting density became slower after 45 s. The initiation rate of surface photografting was about 6.5 Unit/(μm2·s) in the range of 30—45 s.