Structure—Property Behavior of Caprolactone—Allyl Glycidyl Ether Copolymers Cross-Linked by Electron-Beam Irradiation

Abstract

Semicrystalline copolymers of caprolactone and allyl glycidyl ether(CL-AGE) have been crosslinked at various temperatures both above and below the crystalline melting point by electron beam irradiation. Gel fraction increases with irradiation dose up to 40 Mrad and shows slightly higher values when irradiated above the melting point compared to irradiation below the melting point. A stable spherulitic crossed polarizer optical microscopy pattern of the CL-AGE copolymer cross linked in the semicrystalline state persisted over a wide range of temperature even in the melt. In contrast, random intro duction of crosslinks into this material in the melt state re sulted in some restriction on the crystallization process limiting the development of ordered superstructure upon solidification.Measurements of thermal and mechanical properties support the gel fraction results and the microscopy observations.It was concluded that the final solid state properties of the EB-irradiated CL-AGE copolymers are strongly dependent on the morphological state of the material at the time of the EB irradiation process.