A Novel Initiator of [5-(benzyloxy)-4-oxo-4H-pyran-2-yl]methyl-2-bromo-2-methylpropanoateas in Atom Transfer Radical Polymerization of Styrene and Methyl Methacrylate

Abstract

A novel nano-initiator containing kojic acid moiety, [5-(benzyloxy)-4-oxo-4H-pyran-2-yl)methyl-2-bromo-2-methylpropanoate was synthesized by the reaction of 5-(benzyloxy)-2-(hydroxymethyl)-4H-pyran-4-one with 2-bromoisobutyryl bromide in triethylamine and used as initiator in the atom transfer radical polymerization (ATRP) of styrene and methyl methacrylate in the presence of Cu(0)/CuCl2and N,N,Nʹ,N″,N″-pentamethyl diethylenetriamnie (PMDETA). The characteristics of resulting polymers were verified by proton nuclear magnetic resonance spectroscopy (1H NMR), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC). 1H NMR spectra were recorded in deuterated chloroform (CDCl3)with a Fourier transform (FT)-nuclear magnetic (NMR) spectrometer. To investigate the living nature of polymerization, the obtained polymers were subjected to further chain extension reaction. The chain extension of polystyrene (PS) and poly(methyl methacrylate) (PMMA) macroinitiators demonstrated that the chain ends of the obtained PS-Br and PMMA-Br were enable for further functionalization. After chain extension, the GPC curves shifted to high molecular weight. The values of number average molecular weight (Mn)of PS and PMMA increased from 37853 to 40808 g/mol and from 107640 to 156310 g/mol, respectively. These results demonstrated that the chain extension reaction was successful and exhibited the living features of the chain end. To the best of our knowledge, the synthesis of ATRP initiator containing kojic acid moiety has not been reported. Herein, we report the synthesis and characterization of an ATRP initiator containing kojic acid moiety, and its application for the polymerzation of styrene and methyl methacrylate.