Thermal- and photo-polymerization of (meth) acrylates containing a spiro ortho ester moiety and the properties of poly[(meth)acrylate]s.

The syntheses and polymerizations of acrylate (ASOE) and methacrylate (MASOE) containing spiro ortho ester moieties were carried out and the properties of the polymers obtained were investigated. The ring-opening reaction of the spiro ortho ester groups proceeded well during heat polymerization (HC) with the ionic initiators (BSS and HPSS). However, a small amount of unreacted carbon-carbon double bond was observed in the polymers obtained. Not only vinyl polymerization but also a small amount of ring-opening reaction took place during polymerization with radical initiators (BPO, AIBN, DTB and CQ). The poly-(MASOE)s obtained by HC with BSS, BSS/AIBN and BSS/BPO were plastic like polymers. Low volume shrinkage was observed during HC and UVLC of ASOE and MASOE with ionic initiators. These shrinkages were smaller than those of conventional methacrylate.