Synthèse par voie radicalaire de polymères à extrémités hydroxylées, 12. Etude de la copolymérisation du méthacrylate de méthyle avec divers acrylates et méthacrylates. Détermination des microstructures

Abstract

Methyl methacrylate was copolymerized with butyl or isobutyl acrylates, and butyl, isobutyl, or 2,3-epoxypropyl methacrylates, by hydrogen peroxide, in the presence of ethanol under UV irradiation (at 254 nm) at room temperature. The analysis of the microstructures was based on resonance splitting of the methoxy protons of MMA, depending on their environment. This splitting was not obtained with isobutyl and 2,3-epoxypropyl methacrylates. All the products were found to be predominantly syndiotactic.

Determination of the reactivity ratios, sequence distribution and stereoregularity of butyl acrylate‐methyl methacrylate copolymers by means of proton and carbon‐13 NMR

“…6(a) (F M = 0.17), the methoxy resonance signal of the MMA-centred units has been reinterpreted in terms of five major peak signals, each of which is attributed to an individual or two MMAcentred sequences. This has not been observed before because Brosse et al 15 showed the spectra ofBA-MMA of FM = 0.42 and of higher fractions of MMA in the copolymer. It has been found ( Fig.…”

“…Expansions of the methoxy region are shown since in particular this region displays additional resonance of the MMA-centred triads as follows: splitting due to combined configurational (= tacticity) and compositional sequence effects. 15 Brosse et aI. 15 published the 100 MHz proton NMR spectra of BA-MMA copolymers and assigned the split methoxy where 0" is O"BM, the coisotacticity parameter (meso configuration between a BA and a MMA unit) and O"MM is the isotacticity (meso configuration between two MMA units).…”

“…15 Brosse et aI. 15 published the 100 MHz proton NMR spectra of BA-MMA copolymers and assigned the split methoxy where 0" is O"BM, the coisotacticity parameter (meso configuration between a BA and a MMA unit) and O"MM is the isotacticity (meso configuration between two MMA units). An MMM sequence shows no tacticity since in the proton NMR spectrum of PMMA only a single peak signal exists at 3.6 ppm.…”

“…Similarly to the methacrylate series, the propylacrylate-methyl methacrylate (PA-MMA) system has not been studied by 13C NMR. The next homologue (BA-MMA) has been studied by Brosse et al 15 via 1 H NMR. They showed that the methoxy resonances of the MMA unit are sensitive to different configurational sequences.…”

Sequence Distribution and Stereoregularity in Styrene/Butyl Methacrylate Copolymers Obtained at High Conversion by Stable Free-Radical Polymerization

“…Copolymer coisotacticity parameter r is not accessible directly, but has been determined with a trial-and-error method [21] from the values of peak X (F X ). The relative intensities of peak X were compared with those calculated theoretically from Equation (1).…”