A novel sequential photoinduced living graft polymerization
A novel sequential photoinduced living graft polymerization
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DOI：
10.1021/ma990821s
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发表时间：
2000-01-25
期刊：
影响因子：
5.5
通讯作者：
Bowman, CN
中科院分区：
文献类型：
--
作者：
Ma, HM;Davis, RH;Bowman, CN
设计并研究了一种新型的序贯紫外诱导活接枝聚合改性高分子材料的方法。该方法包括两个步骤。在第一步中，在二苯甲酮（BP）溶液存在下，在UV照射下在基底上形成表面引发剂；在第二步中，通过由表面光引发剂引发的活性聚合将单体接枝到基底上。通过接枝丙烯酸（At）制备了表面带负电荷的疏水多孔聚丙烯（PP）膜。实验结果表明，接枝密度和接枝聚合物链长可以通过选择第一步和后续步骤的反应条件来控制。与同期接枝法相比，新型顺序光诱导接枝法的接枝量占聚合物总量的比例提高了4倍。此外，还提出了一种反应机理，并通过实验进行了验证。对于抽氢引起的表面引发剂形成，动力学研究表明，反应速率随BP浓度的增大而增大。对于第二步的接枝聚合，接枝聚合速率与单体浓度呈线性关系。
A novel sequential ultraviolet (UV)-induced living graft polymerization method has been designed and investigated to modify polymeric materials. This method consists of two steps. In the first step, a surface initiator is formed on a substrate under UV irradiation in the presence of benzophenone (BP) solutions; in the second step, the monomers are grafted to the substrate by a living polymerization initiated by the surface photoinitiator. Hydrophobic porous polypropylene (PP) membranes were made hydrophilic and with negatively charged surface by grafting acrylic acid (At). Experimental results demonstrated that grafting density and graft polymer chain length can be controlled by choosing the reaction conditions in the first step and in the subsequent step(s) independently. The amount of grafted polymer relative to the total amount of polymer from the novel sequential photoinduced graft polymerization method is 4-fold greater than that of the simultaneous grafting method for the system studied. In addition, a reaction mechanism was proposed and confirmed in the experiments. With regard to the surface initiator formation caused by hydrogen abstraction, the kinetic studies show that the reaction rate has a maximum value which depends on BP concentration. With regard to the graft polymerization in the second step, there is a linear relationship between the graft polymerization rate and the monomer concentration.