The Synthesis And Study Of Cationic Photoinitiators And Polymeric Free-radical Photoinitiators In UV Technology

UV coatings have been extensively used in many fields. Because of its free from pollution, quickly solidify and economic for energy. One of the most important ingredient which make up of UV coating is photoinitiator, so it's very necessary to study photoinitiator which has good performance. Photoinitiators usually have two kinds: one is used for radical polymerization ,the other is for cationic polymerization. But radical photoinitiator which used in radical polymerization is sensitive to oxygen and cationic photoinitiator's maximal absorption wavelength does not match a lot of light sources that can be obtained commercially UV-curable coating consists of two basic ingredients : oligmers and photoinitatiors. In this article ,we will study the photoinitatiors. After UV-curable coating cured by UV light, photoinitatior is not used up. Some of those will migrate to the surface of coating which cause film yellow. Some kind of photoinitatiors are not compatible with monomers or oligmers. In order to overcome those problems, making polymeric photoinitatior becomes important. There are two ways to prepare polymeric photoinitatior: one is bonding photoinitatior to the chain of polymer or oligmers directly; the other is introduce some polymeric groups into the structure of photoinitatior. In this papers, we have studied the latter and introduce one, two or three polymeric groups into the structure of benzophenone. In addition, we also prepared two kind of cationic photoinitiators: p-benzyldiphenyliodonium hexafluorophosphate and p-benzoyldip-henyliodonium hexafluorophosphate . a novel hybrid cationic phot-oinitiator (4-benzoyl-1,1'-biphenyl-4-yl)(phenyl)iodoniumhexafluorophosphate was designed and synthesized. This article has five parts:1. introduction 2. experiments3. discussion and results4. summary5. reference...