Chantal Bonnans-Plaisance

Functional polythiiranes: 3. Synthesis and characterization of polythiiranes containing biphenyl units in the side chain

Abstract The synthetic route to polythiiranes bearing side chain biphenyl groups is described. [(4-Biphenyl)methylthio]methylthiirane afforded relatively low molecular weight polymers in 50% yield, while (4-biphenyl)methyl 2-[(2,3 epithiopropyl)-thio]ethanoate afforded high molecular weight polymers in high yields.

Functional polythiiranes 4

SummaryNew polymers with polythiiranes main chains and PEO side chains have been prepared by ring opening polymerization of the corresponding thiirane monomers. These polymers were characterized by 1H and 13C NMR and their average molecular weight were studied by SEC. For side chains containing three or more EO units, the polymers were soluble both in water and in organic solvents.

Functional polythiiranes: 1. Comparative study of the anionic polymerization of mercaptomethylthiirane and hydroxymethylthiirane initiated by quaternary ammonium dithiobenzoate

Abstract The occurrence of chain transfers has been studied during the anionic polymerization of protic thiiranes in dimethylformamide initiated by tetramethylammonium dithiobenzoate. Results on polymer molecular weights and 13 C nuclear magnetic resonance spectra as well as polymerization rates have been used in a comparative study of hydroxymethylthiirane and mercaptomethylthiirane polymerizations. We have demonstrated that chain transfers occur significantly with mercaptomethylthiirane while they may be considered as non-existent with hydroxymethylthiirane. This is due to the equilibrium between ‘thiolate’ and ‘olate’ ions being more favourable to thiolate because of the relative acidity of thiols and alcohols.

Preparation and characterization of poly(thiirane) block copolymers with pendent hydroxy groups

Abstract 13 C n.m.r. spectroscopy was used to differentiate between block and statistical copolymers of hydroxy-methylthiirane and methylthiirane. Block copolymers could be exclusively obtained if hydroxymethylthiirane constituted the first sequence; however, if the first sequence consisted of methylthiirane, the synthesis of block copolymers failed because of a termination reaction. We demonstrate that the termination reaction is partially avoided in a protic medium.

Functionalization of PS and PMMA by a chain transfer agent and study of their degradation

Chain transfer to ethylene bis(mercaptoacetate) in the free radical polymerisation of styrene and methyl methacrylate leads to ester and sulfide-containing polymers functionalized both in chain ends as well as in the chains. The functionalized polystyrene can be (bio)degraded from ester functions as well as from sulfide functions. Attempts to chemically degrade functionalized poly(methyl methacrylate) from sulphur functions was less successful.

Functional polythiiranes 6: Hydrolysis of side chains ester and monothioacetal functions of comb-like polythiiranes

The hydrolysis of comb-like polymers with polythiirane main chains and PEO side chains linked with monothioacetal function or ester function was studied in various conditions. The monothioacetal link exhibited a rather good stability except in very acidic conditions. In a buffered medium, acidic as well as basic, the hydrolysis of the ester link was degenerated first order. In basic stoichiometric conditions the kinetics is second order and a ionic strength effect was evidenced. The energy of activation was also evaluated in these conditions.