Polyethylene terephthalate (such as scrap) is digested with excess glycol and the product is reacted with an aliphatic dicarboxylic acid or ester forming derivative thereof to form a random copolyester polyol having MW 1000-4000 and in which terephthalic acid residues are 10 - 60 % of total acid residues on a molar basis.  
                            用过量
乙二醇消化聚
对苯二甲酸乙二醇酯(如废料),然后将产物与脂肪族二
羧酸或其
酯类衍
生物反应,形成无规共聚酯多元醇,其分子量为 1000-4000,其中
对苯二甲酸残留量占总酸残留量的 10-60%(以摩尔计)。