| 摘要 |
<p>Condensation polymers contain ketone groups along the principal polymer chain in a lateral chain in a position adjacent to the principal polymer chain, the quantity of ketone groups being sufficient to cause accelerated photo-degradation of the polymer to make it brittle or friable by exposure to U.V. light. The polymers are either polyamides made from a diacid and diamine of which one has the formula: in which R is alkyl, aryl, alkaryl, or alkenyl of 1 to 12C atoms; R' is H or alkyl of 1 to 6C atoms, and R" is NH2 or .COOH. or polyesters made from a glycol and is diacid of which one has the above formula in which R" is -OH or -COOH. The polymers are used for packaging applications.</p> |
