光聚合现状与展望

本文叙述了自由基和阳离子聚合光引发剂体系的最新进展,并且提供了不同引发模式下在所有光引发体系中有关引发效率、波长限制和环境安全问题的解决办法。在过去10年里,通过光聚合制备了复杂或纳米结构的大分子,因此本文也介绍了光聚合在生物材料、表面改性和纳米复合材料领域的新兴应用。     

［环戊二烯-铁-二苯甲烷］六氟磷酸盐的光催化研究

芳茂铁盐是一类有效的用于环氧聚合的光引发剂。通过二茂铁和二苯甲烷的配体交换反应,制备了新型的芳茂铁盐［环戊二烯-铁-二苯甲烷］六氟磷酸盐（［Cp-Fe-Bp］⁺PF₆^-）。研究了其紫外－可见吸收性能和光解,发现［Cp-Fe-Bp］⁺PF₆^-）由d-d跃迁产生的在300 nm以上的吸收使其适合长波紫外光源。通过实时红外研究了［Cp-Fe-Bp］⁺PF₆^-）的光引发活性,表明能有效地引发3,4-环氧基环己基甲酸-3′4′-环氧基环己基甲酯（ERL-4221）开环聚合,过氧化苯甲酰能使其光引发活性显著提高。     

Onium Salts of Amino Acids as Co‐Initiators in Photoinduced Free‐Radical Polymerization

Summary: The onium salts of selected aliphatic and aromatic amino acids were investigated as electron donors in photoinduced free radical polymerization, in conjunction with either DIBF or BP as sensitizer. The laser flash photolysis experiments unmistakably documented that the free radical formation occurs via an electron transfer reaction from the amino acid salt to the chromophore triplet state. The kinetic studies clearly showed that either the DIBF or BP onium salts of selected aliphatic and aromatic sulfur‐containing amino acids exhibit a significant increase in the efficiency of free‐radical polymerization of TMPTA as compared to non‐sulfur‐containing co‐initiators and that the efficiency of all tested electron donors is only slightly dependent on the cation type coupled with co‐initiators tested.

Possible mechanism for the free radical photoinitiated polymerization.