Synthesis of Novel Aba-Type Amphiphilic Copolymers Including 2-Hydroxypropyl Propionate and N-Isobutoxymethyl Β-Alanine by Peg-Dialkoxide Initiated Hydrogen-Transfer Polymerization

Abstract

Novel ABA-type amphiphilic copolymers were prepared using end-groups activated poly (ethylene glycol) (PEG) as an initiator of hydrogen-transfer polymerization (HTP). For this purpose, PEG with 1450 Da (PEG-1450) was treated with the equivalent amount of sodium hydride to synthesize PEG with dialkoxide end-groups, namely PEG-dialkoxide. Using the PEG-dialkoxide as a macroinitiator, base-catalysed HTP of 2-hydroxypropyl acrylate (HPA), and N-isobutoxymethyl acrylamide (BMA) were performed to achieve the novel ABA-type block copolymers. The copolymers were obtained with relatively high yields. Characterization of the ABA-type amphiphilic copolymers was carried out using FTIR and MALDI mass spectrometry. FTIR spectra of the copolymers exhibited some characteristic bands assigning to the functional groups arising from the mechanism of HTP. Molar mass distributions of the copolymers from the MALDI mass study pointed out that chain extensions by mass in each copolymer were almost equal. Hence, the MALDI mass spectra of the copolymers revealed that chain extensions of PEGs by HPA, and BMA units were successfully fulfilled.