申请人:SOLVAY SA
公开号:US20180171072A1
公开(公告)日:2018-06-21
The invention pertains to an improved method for synthesizing a branched poly(hydroxyl acid) polymer comprising effecting polycondensation reaction of a monomer mixture comprising: (i) at least one hydroxyl acid having only one hydroxyl group and only one carboxylic acid group [hydroxyacid (A)]; (ii) at least one polyol comprising at least three hydroxyl groups and being free from carboxylic acid group [polyol (H)]; (iii) at least one polyacid comprising at least three carboxylic acid groups and being free from hydroxyl groups [polyacid (O)]; and (iv) at least one carboxylic acid having one or two carboxylic acid groups and being free from hydroxyl group [acid (C)], wherein the amount of said acid (C) is such that the number of carboxylic acid groups thereof is comprised between 0.0001 to 0.010% with respect to the number of hydroxyl groups of hydroxyacid (A).