Unsatd. polyester prodn. from glycol (terephthalate oligomers) - formed as waste prods. in polyethylene terephthalate prodn.

摘要

An unsatd. polyester is produced from a compsn. (I) comprising glycols and oligomers of glycol terephthalates recovered from a waste stream from the prodn. of polyethylene-terephthalate. The process comprises: (a) mixing the compsn. (I) with an aliphatic polyol or polyetheralcohol, (b) transesterifying the mixt. and (c) polyesterifying the transesterified mixt. with an ethylenically unsatd. dicarboxylic acid. The physical properties of the polyester produced are comparable to those of commercial polyesters. The process is also of ecological and economical interest.