Stabilized poly(beta-methyl-delta-valerolactone).

摘要

Polyester polyols containing the following recurring unit derived from beta -methyl- delta -valerolactone @ @OCH2CH2CH(CH3)CH2CO @@ used to be low in stability. It has been discovered that the stability of the polyester polyols of this type can be improved by reducing the acid value to down 0.25 or lower, and that this can be effected by heat treatment under reduced pressure to remove low-boiling compounds and/or by addition of an organic carbodiimide.