The development of petroleum-based plastics is one of the crowning achievements of the 20th century, but they come with a hefty cost. the vast scale of plastics manufacturing and the environmental consequences associated with disposal have illuminated the limits to which the planet can cope with our current “take, make and dispose” model of resource utilization. Biodegradable plastics derived from renewable sources offer an attractive alternative, but so far they can’t match the price and performance of petroleum plastics. Now, researchers at Stanford and IBM Research report the development of new chemical approaches that could efficiently and inexpensively generate biodegradable plastics suitable for making an array of items as diverse as forks, medical devices and fabrics. As with many chemical reactions, creating biodegradable polyesters requires the assistance of a catalyst – a special class of chemical that increases the rate of a reaction or pushes it over an energetic hurdle. The standard catalysts used to make biodegradable plastics are metal-based, which are difficult or expensive to remove from the final material, and do not degrade in the environment. The research group from Stanford and IBM Research presents an alternative catalyst made from common organic compounds – thiourea with a metal alkoxide. The result is a catalyst that is both fast and selective, meaning that it excels at accelerating and facilitating reactions and that it doesn’t alter the resulting polymer’s shape or properties once it is formed. http://news.stanford.edu/press-releases/2016/07/28/catalyst-making-radable-plastics/
Polyesters--- Should be degraded in high alkalinity into alcohols metal carboxylate . here they are talking metal alkoxide which to me it means ,potassium or sodium hydroxide which should be highly concentrated , for me means melt the caustic soda and that will chew up the polyester .
