PVC片材表面的光接枝亲水化处理

采用光接枝聚合方法对商品化PVC片材进行了表面亲水化处理。以二苯甲酮作引发剂 ,丙烯酸为接枝单体研究了反应过程中单体浓度、引发剂浓度、反应时间对亲水化效果的影响。衰减全反射红外光谱 (ATR FTIR)分析发现 ,在 15 5 5cm-1处出现COO-的特征峰 ,证明丙烯酸已经接枝到材料表面。随着反应时间的延长 ,接触角持续下降 ,3 0s以后趋于恒定 ,最低可达 3 3°。较低单体浓度下 ,均聚反应较弱 ,材料的亲水性要好于高单体浓度时的情况。同样 ,较低引发剂浓度时 ,引发剂的自屏蔽效应弱 ,有利于接枝反应 ,接触角要比高引发剂浓度条件下小

Surface Hydrophilization of PVC Sheet by Photografting Modification

The surface of commercial PVC sheet was modified by photografting and the contact angle decreased considerably. The influence factors to hydrophilization such as initiator concentration, monomer concentration and irradiation time were investigated by using benzophenone as photoinitiator and acrylic acid (AA) as monomer. The ATR-FTIR spectrum showed a strong absorption peak at the wave number of 1 555 cm -1 that attributed to the carboxylic group COO -. This indicates that AA was indeed grafted onto the surface of PVC. The contact angle of grafted PVC sheet decreased dramatically with the prolongation of irradiation time. After 30 s treatment, the decline of contact angle become smooth and incline to a constant, the lowest of them is 33 degree. The self-screen effect of initiator resulted that low initiator concentration is more preferable to obtain a good hydrophilization. Similarly, at the same initiator concentration, the lower monomer concentration gives lower contact angle due to the counterbalance between graft polymerization and homopolymerization.