Scientists have come up with a new polymer that can degrade by ultraviolet radiation. This faster-degrading plastic can degrade on a realistic time scale if it gets lost in the aquatic environment.
While research of degradable plastics has received much attention in recent years, obtaining a material with the mechanical strength comparable to commercial plastic remains a difficult challenge.
Scientists have been developing this plastic called isotactic polypropylene oxide or iPPO. Exposing iPPO to UVA light (365 nm) resulted in photolytic degradation.
While its original discovery was in 1949, the mechanical strength and photodegradation of this material was unknown before this recent work. The high isotacticity (enchainment regularity) and polymer chain length of their material makes it distinct from its historic predecessor and provides its mechanical strength.
While iPPO is stable in ordinary use, it eventually breaks down when exposed to UV light. The change in the plastic’s composition is evident in the laboratory, but visually, it may not appear to have changed much during the process.
The rate of degradation is light intensity-dependent, but under their laboratory conditions, the polymer chain lengths degraded to a quarter of their original length after 30 days of exposure.
Commercial fishing contributes to about half of all floating plastic waste that ends up in the oceans. Fishing nets and ropes are primarily made from three kinds of polymers: isotactic polypropylene, high-density polyethylene, and nylon-6,6, none of which readily degrade. By having a plastic material that readily degrades, large amount of waste can be easily removed.