Abstract
Polymethacrylates (5) containing pendant spiro ortho ester group were prepared by the reaction of ε-caprolactone and the corresponding polyfunctional epoxides (4) with different compositions, which were obtained by radical (co) polymerization of methyl methacrylate and/or glycidyl methacrylate varying the feed ratio. 5 with quantitative introduction of SOE moiety to the polymer side chain were obtained in the presence of BF3OEt2 in ca. 50% yield. These polymers were treated with BF3OEt2 in refluxing dichloromethane to afford the crosslinked polymers (6) by the double ring-opening of SOE moiety in high yields. To evaluate the volume change during the crosslinking of 5, crosslinking of 4 was also carried out in the same condition to obtain the solvent-insoluble polymers (8) quantitatively. From the determination of densities of 6 and 8, nearly zero volume change (-0.9-+0.5%) were observed during the crosslinking of 6.
