MALDI-TOF MS analysis of the self-termination products in the anionic methyl methacrylate/tert-butyl acrylate block copolymerization

0446686 - ÚMCH 2016 RIV DE eng J - Journal Article
Vlček, Petr - Čadová, Eva - Horský, Jiří - Janata, Miroslav
MALDI-TOF MS analysis of the self-termination products in the anionic methyl methacrylate/tert-butyl acrylate block copolymerization.
Polymer Bulletin. Roč. 72, č. 9 (2015), s. 2227-2239. ISSN 0170-0839. E-ISSN 1436-2449
Institutional support: RVO:61389013
Keywords : anionic polymerization * acrylates * block copolymer
Subject RIV: CD - Macromolecular Chemistry
Impact factor: 1.371, year: 2015

The p(MMA-b-t-BuA) copolymer was prepared using the initiation system methyl 2-lithioisobutyrate/lithium/tert-butoxide (MIB-Li/t-BuOLi). A low-molecular-weight fraction was isolated and analyzed by MALDI-TOF mass spectrometry with the aim to find out structures of products of self-termination, which proceeds mainly after the addition of t-BuA into the living PMMA. The main self-termination products are formed after addition of one or two t-BuA units onto living PMMA-Li by backbiting reaction of t-BuA-Li chain-ends and carbonyl group of the antepenultimate MMA units of the same chain. The oxoesters generated in this way contain hydroxygroup, and its hydrogen can protonize any of the living chains, regardless of the type of its terminal unit. Signals of the chains, terminated by this protonization, have also been found in the spectra. Thus, the first direct evidences for the structures of the self-termination products in the anionic methacrylate/acrylate block copolymerization were obtained in this way.
Permanent Link: http://hdl.handle.net/11104/0248730