Polyol block copolymer, compositions and processes therefor

A process for producing a polyol block copolymer in a multiple reactor system;

• the system comprising a first and second reactor wherein a first reaction takes place in the first reactor and a second reaction takes place in the second reactor;
• wherein the first reaction is the reaction of a carbonate catalyst with CO2 and epoxide, in the presence of a starter and/or solvent to produce a polycarbonate polyol copolymer and the second reaction is the reaction of a DMC catalyst with the polycarbonate polyol compound of the first reaction and epoxide to produce a polyol block copolymer, wherein (i) the product of the first reaction is fed into the second reactor as a crude reaction mixture, wherein the product in the crude reaction mixture is not isolated prior to addition to the second reactor, and (ii) the epoxide and the polycarbonate polyol compound of the first reaction are fed into the second reactor in a continuous or semi-batch manner, and/or (iii) the product of the first reaction has a neutral or alkaline pH on addition to the second reaction;
• wherein the reactors are nested.