| 摘要 |
Photodegradable compsns. comprise a polymer chosen from polyethylenes, polystyrenes and copolymers of ethylene or styrene, and 1-500 ppm. based on polymer, of an Fe (II) salt of a carboxylic acid with an alkyl chain of >=6C and a COOH, SO3H, alcohol or amide gp. at the 2,3,4, or 5 posn. relative to the carboxylic acid gp. The compsn. pref. contains 1-250 ppm. S. The Fe (II) salts are not toxic thus enabling the compsns. to be used in foodstuff applications; not extractable by water; compatible with and easily dispersible in polymers; not thermodegrading towards the polymer during processing; do not generate a rancid odour during storage of the compsns. as do prior art Fe III salts Degradation of the compsn. in sunlight is rapid, e.g. a 40u polyethylene film contg. 100 ppm Fe II salt, exposed in the open air degraded after 100 days.
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