La(III)-Catalysed degradation of polyesters to monomers via transesterifications.

Tris(acetylacetonato)lanthanum(III) (1 mol%) catalyses the degradation of poly(butylene succinate) ( M w = 90 700) by transesterification in MeOH at 90 °C for 4 h, thus affording dimethyl succinate (>99% yield) and 1,4-butanediol (98% yield). Moreover, the quantitative degradations of poly(ethylene adipate), poly(ethylene terephthalate) and poly(butylene terephthalate) are also reported.