Photopolymerization and the related properties of dendritic methacrylated polyesters

Abstract

Three kinds of photopolymerizable dendritic polyesters have been synthesized based on 1,1,1-trishydroxymethyl-propanol, pentaerythritol, and dipentaerythritol as polyols and polycarboxylic acid anhydride, modified with glycidyl methacrylate and then esterified by acetic anhydride, which contain a maximum of 6, 8, and 12 methacrylic groups at the molecular chains, respectively. Their dynamic viscosity and UV-cure speed have been measured by a spinning viscometer and the tack-free time of the product, and the mechanical properties have been investigated by pendulum hardness and tensile strength of the UV-cured films. It is found by comparison with traditional linear epoxy (meth)acrylate oligomers with lower molecular weights that the dynamic viscosity of the dendritic methacrylated polyesters is only half of that for the linear oligomers. However, the UV-cure speed is about five times of that for the latter. The tensile strength of the cured films increases with the functionality of the polyester and a small amount of comonomer addition. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 499–504, 2001