PROCESS FOR CONTROLLING THE STRUCTURE OF A BLOCK COPOLYMER BY SELECTIVE COPOLYMERIZATION, BY RING OPENING, OF CYCLIC CARBONATE AND LACTONE MONOMERS

摘要

The invention relates to a process for controlling the structure of a block copolymer by selective copolymerization, by ring opening, of cyclic carbonate and lactone monomers in the presence of a catalyst based on methanesulfonic acid, the said process comprising a sequence of stages carried out strictly in the following order:a) dissolving the cyclic carbonate monomer in a nonchlorinated aromatic solvent,b) adding, to the monomer solution, a bifunctional initiator chosen from diols or water,c) adding methanesulfonic acid (MSA) as catalyst of the polymerization reaction,d) when all the cyclic carbonate has been consumed, a telechelic polycarbonate capable of acting as macroinitiator of polymerization of the lactone is obtained,e) adding the lactone to the reaction medium in order to selectively obtain a block copolymer.