乙酰乙酸基聚丙烯酸酯与端烯基聚氨酯交联反应机理

乙酰乙酸基聚丙烯酸酯与端烯基聚氨酯交联反应机理唐黎明＊郭伟刘德山周其庠（清华大学化工系北京１０００８４）关键词乙酰乙酸基，聚丙烯酸酯，聚氨酯，双键，交联机理１９９６－０８－２０收稿，１９９６－１２－０５修回近年来，含有乙酰乙酸基团的聚合物在涂料、粘合...

Crosslinking Mechanism between Acetoacetylated Polyacrylate and Vinyl ended Polyurethane

An acetoacetylated polyacrylate and a vinylic groups ended polyurethane were synthesized. In the presence of a basic catalyst, they can crosslink with each other via the Michael reaction to prepare a thermoset coating at ambient temperature. A model of this crosslinking system, the reaction of ethyl acetoacetate (EAA) with methyl acrylate (MA), was designed to investigate the crosslinking mechanism. The results indicate that the two active hydrogen atoms of the acetoacetyl functionality can participate in the reaction and both mono and bis adducts are formed. The yield of bis adduct increased with decreasing feeding molar ratio of EAA and MA. Two composite coatings with molar ratios of acetoacetyl content of polyacrylate to double bond content of polyurethane being 0 6/1 and 1/1 were prepared. The former coating showed higher crosslinking degree and better properties than the latter one.