| 摘要 |
Microbiologically produced polymers based on beta -hydroxybutyric acid of improved melt stability containing a polyethylenically unsaturated compound containing at least two reactive groups of the formula -CH=CR1- in which R1 is hydrogen, a lower alkyl or a phenyl radical and in which compound R1 may differ from one -CH=CR1- group to another with the proviso that where the compound contains only two groups of the formula -CH=CR1-, they are not both contained in: R-CH=CH1-@-O- groups where R is hydrogen, a lower alkyl, or a phenyl radical. The polyethylenically unsaturated compounds are most effective when used in the presence of free radical generating agents, although thermal and shear induced rn activation may be employed. Preferred ethylenically unsaturated compounds contain at least two allyl compounds, at least two maleimido groups or at least three groups of formula: <CHEM> r |
