Water soluble, low migration and visible light photoinitiators for greener photopolymerization

Abstract

In this work, novel monomeric, polymeric and mesomeric (high enough molecular weight to provide lower migration but not high enough to be called a macromolecule) photoinitiators (PIs) were synthesized with the aim of achieving the “green” properties of migration stability, water solubility, biocompatibility and visible light absorption. Their properties and performances were examined in terms of photophysical and photochemical aspects. In the third chapter, the first cyclopolymerizable monomeric PI in the literature (TXdMA) was produced by introducing both TX chromophore and hydrogen donating tertiary amine functionality on its structure. The fourth chapter reports two water soluble mesomolecule photoinitiators (TXBP and BPBP), synthesized by the susbstitution of biocompatible bisphosphonic acid functional groups into TX and benzophenone (BP); the first such PIs in the literature. In the fifth chapter, a water soluble mesomolecule photoinitiator (TXBP2) was fabricated through bisphosphonate functionalization of TX. The sixth chapter reports synthesis of a TX-based water soluble polymeric photoinitiator (PAA TX) from the aza-Michael reaction of a poly(amido amine) to 9-oxo-9H-thioxanthen-2-yl acrylate. The last chapter describes the syntheses of two novel water soluble multifunctional polymeric photoinitiators (PEI-I2959-Ts and PEI-I2959) through incorporation of I2959 into branched poly(ethyleneimine) (Mw = 1800 g/mol).