Microstructural characterisation and properties evaluation of poly (methyl methacrylate-co-ester)s

Abstract

The present work provides detailed copolymerization behavior of methyl methacrylate (MMA) with 2-methylene-1,3-dioxepane (MDP), a cyclic ketene acetal under conventional free radical polymerization conditions at 120°C. An in-sight to the microstructure of the homo- and co-polymers is also made available using ID and 2D NMR spectroscopic techniques. For the first time we showed the formation of crystalline degradable aliphatic polyester, homo poly (2-methylene-1,3-dioxepane) (PMDP) with reduced branches using radical-ring-opening-polymerisation. The Copolymerization brought degradability and many other new properties to the poly (methyl methacrylate) (PMMA) vinyl polymer. Various degradable materials based on MMA and 2-methylene-1,3-dioxepane (poly (MMA-co-ester)s) containing varied amounts of ester linkages ranging from amorphous to crystalline and with different glass transition temperatures are generated. The presence of very low fraction of the ester linkages (about 10 mol %) could led to a significant increase in the thermal stability of PMMA. These materials are shown to have heat-shrinkable-shape-memory properties also. © 2006 The Society of Polymer Science, Japan.