Synthesis And Photopolymerization Of Acrylate-Propenyl Ether Hybrid Monomers

Photopolymerization can be divided into two categories, one is free radical polymerization, and another is cationic polymerization. Free radical and cationic photopolymerization possessed some intrinsic shortcoming, such as high volatility, strong oxygen inhibition, large volume shrinkage or low polymerization rate, high humidity sensitivity. Hybrid photopolymerization technique could be considered as a hopeful solution to overcome the drawbacks of pure systems, which contained two different systems, blend and hybrid monomer. Hybrid monomer was a kind of monomer bearing two types of active group in one molecule. This structure would change the kinetics of each function group and have potential to form more uniform chemical bonded interpenetrating polymer networks (IPN) to improve the mechanic properties of cured film.In this thesis, three different chain length hybrid monomers, containing acrylate and propenyl ether group, was synthesized by three-step reaction through 1.3-propanediol, 1.4-butanediol, 1.6-hexanediol, allyl bromide and acryloyl chloride. Fourier transform infrared spectra (FTIR) and ~1H NMR spectra were used to identify the structure of hybrid monomers. Their photopolymerization kinetics was investigated with real time FTIR. Results showed that the hybrid monomer could photopolymerize effectively and both free radical and cationic polymerization processes were improved. When 2-Hydroxy-2-methyl-1-phenyl-1-propanone (1173) was introduced into hybrid system containing Uâ…¥-6976, the final conversion of propenyl ether double bond and polymerization rate (R_p) increased obviously. The comparison of photopolymerization kinetics between hybrid and blend system was investigated as well. It showed that the blend system had much slower Rp than that of hybrid monomer, either of acrylate double bond or propenyl ether double bond, and propenyl ether double bond conversion of hybrid monomer was much higher than that of the blend system at the end. It was also demonstrated that hydroxyl compound had no negative influence on propenyl ether-acrylate hybrid monomers, which will be instructive to develop new low humidity sensitive cationic polymerizable vinylether-containing monomer.