Photoinitiated free radical polymerization using benzoxazines as hydrogen donors


TASDELEN M. A. , Kiskan B. , Yagci Y.

MACROMOLECULAR RAPID COMMUNICATIONS, vol.27, no.18, pp.1539-1544, 2006 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 27 Issue: 18
  • Publication Date: 2006
  • Doi Number: 10.1002/marc.200600424
  • Title of Journal : MACROMOLECULAR RAPID COMMUNICATIONS
  • Page Numbers: pp.1539-1544

Abstract

Free radical polymerization of methyl methacrylate (MMA) is initiated upon irradiation at lambda > 350 nm in CH(2)Cl(2) that contains benzoxazine (P-a) and one of the following photosensitizers: benzophenone (BP), thioxanthone (TX), 2-chlorothioxanthone (CTX), 2-isopropyl thioxanthone (ITX), and camphorquinone (CQ). The postulated mechanism is based on the intermolecular reaction of the excited photosensitizer with the tertiary amino moiety of the ground state P-a and a subsequent hydrogen abstraction reaction. The resulting aminoalkyl radicals initiate the polymerization. The incorporation of P-a groups into polymers is demonstrated by spectroscopic methods. The possibility of deep curing using the described photoinitiating system followed by the thermal ring opening of the incorporated P-a groups is also demonstrated.