Methylmethacrylate polymerization photoinitiated by 1‐(bromoacetyl)pyrene

Abstract

ABSTRACT:The photopolymerization of methylmethacrylate induced by pyrene, 1-acetylpyrene (AP), and 1-(bromoacetyl)pyrene (BP) has been investigated. Under all conditions employed, pyrene was completely ineffective. Introduction of a carbonyl and a bromo group in pyrene enhanced the polymerization efficiencies. Efficiency of AP as photoinitiator was very low; however, BP was proved to be a good photoinitiator. The polymerization with BP follows first-order kinetics with respect to monomer conversion, with a shorter induction period as compared with that of AP. The value of the initiator exponent (0.5) and the linear dependence of reciprocal average degree of polymerization on the square root of the initiator concentration suggest radical polymerization with bimolecular termination. IR and NMR spectra showed the atactic nature of polymethylmethacrylate.

Copolymerization of n‐butylacrylate with methylmethacrylate by a novel photoinitiator, 1‐(bromoacetyl)pyrene

“…Introduction of chromophoric group ( COCH 3 ) in pyrene is expected to enhance its efficiency. Moreover, heavy atoms such as Br and Cl are also known to cause a significant rise in the photoinitiation ability of the dyes [10,12]. A detailed polymerization kinetics and mechanism with 1-(bromoacetyl)pyrene (BP) as sole photoinitiator for copolymerization of BA with MMA are discussed.…”

“…Progress in the chemistry of photopolymerizable compounds results not only from the development of new and novel monomers but also from new initiators. Dyes have been extensively used as photosensitizers/photoinitiators for the polymerization of commercially important monomers 8–12.…”