| 摘要 |
A degradable polymer composition is disclosed which comprises a blend of a normally stable chemically saturated polymer, such as polyethylene, a less stable chemically unsaturated polymer or copolymer, such as a styrene/butadiene block copolymer, or natural rubber, an antioxidant active over a limited period and a latent pro-oxidant, such as an organic salt of a transition metal, e.g. cobalt naphthenate. The presence together of the anti-oxidant and the pro-oxidant give rise to a period of induction before a sharp loss of physical strength occurs, whereby the period of induction can be exploited as the effective working life of the polymer composition. The polymer composition preferably also includes filler particles of a directly biologically sensitive material such as natural starch, a derivative of natural starch, a natural protein or a natural cellulose product or a powdered sugar of melting point higher than the processing temperature of the host polymer composition, whereby, the biological breakdown, in natural environments or in the especially biologically active surroundings of composting urban garbage, of the molecular fragments created by the onset of oxidative scission of the molecular chains of the chemically saturated polymer is accelerated by the presence of said filler particles.
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