Performance analysis of acylphosphine oxides in photoinitiated polymerization
Performance analysis of acylphosphine oxides in photoinitiated polymerization
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DOI：
10.1016/s0032-3861(01)00221-x
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发表时间：
2001-08-01
期刊：
影响因子：
4.6
通讯作者：
Viet, T
中科院分区：
文献类型：
--
作者：
Decker, C;Zahouily, K;Viet, T
已评估了酰基氧化膦在不同类型的UV固化树脂中的引发效率。实时红外光谱法被用来监测在现场的聚合过程中暴露于紫外线辐射的薄涂层。与典型的自由基光引发剂相比，酰基氧化膦被证明是最有效的聚合速率和固化程度，主要是因为它们的快速光解。正面聚合反应很容易进行与这种光漂白引发剂，从而使厚标本是通过简单的暴露于阳光下深通过固化。因为它们在350-400 nm区域内吸收，酰基氧化膦被证明特别适合于引发着色体系和用于外部应用的保护涂层的光聚合，所述外部应用包含UV吸收剂型光稳定剂。这些光引发剂在官能化聚合物如丙烯酸化聚异戊二烯和具有侧链乙烯基的聚丁二烯的光交联中也实现了上级性能。添加少量的三官能硫醇被证明大大加快交联聚合，不溶解在0.3秒的UV曝光内实现，即使对于低至0.1重量%的引发剂浓度。(C)2001爱思唯尔科技有限公司版权所有。
The initiation efficiency of acylphosphine-oxides has been evaluated in different types of UV-curable resins. Real-time infrared spectroscopy was used to monitor in situ the polymerization process in thin coatings exposed to UV-radiation. When compared to typical radical photoinitiators, acylphosphine oxides proved to be the most efficient ones with respect to both the polymerization rate and the cure extent, mainly because of their fast photolysis. Frontal polymerization proceeds readily with such photobleachable initiators, thus allowing thick specimens to be deep-through cured by simple exposure to sunlight. Because they absorb in the region of 350-400 nm, acylphosphine oxides proved particularly well suited to induce the photopolymerization of both pigmented systems and protective coatings used in exterior applications, which contain UV-absorber-type light stabilizers. Superior performance was also achieved with these photoinitiators in the photocrosslinking of functionalized polymers, such as acrylated polyisoprene and polybutadiene with pendent vinyl groups. The addition of small amounts of a trifunctional thiol was shown to drastically speed up the crosslinking polymerization, insolubilization being achieved within a 0.3 s UV-exposure, even for initiator concentrations as low as 0.1 wt%. (C) 2001 Elsevier Science Ltd. All rights reserved.