Bio-assimilation master batch composition, processes for producing polymeric bioassimilating material therefrom, and products produced therefrom

A bio-assimilation masterbatch composition for rendering a polyolefin host polymer bio-assimilable after an intended useful life of a polymer article formed from the polyolefin host polymer, the bio-assimilation masterbatch composition comprising, in a single storage-stable pelletized masterbatch:

• (a) a polyolefin carrier resin comprising low density polyethylene, linear low density polyethylene, polypropylene, or a blend thereof;
• (b) a transition-metal carboxylate comprising a carboxylate salt of manganese, cobalt, iron, copper, cerium, vanadium, titanium, nickel, or a combination thereof, the transition metal being present in an amount effective to catalyze hydroperoxide decomposition in the polyolefin host polymer after depletion of an antioxidant package;
• (c) the antioxidant package comprising a hindered phenolic primary antioxidant and a phosphite secondary antioxidant, the antioxidant package being present in an amount selected to inhibit abiotic oxidation of the polyolefin host polymer during the intended useful life and to permit accelerated abiotic oxidation after depletion of the antioxidant package;
• and
• (d) a bio-assimilation promoter package comprising one or more biodegradable or bio-assimilation-promoting polymers and present in an amount effective to promote microbial colonization and bio-assimilation of oxidized low-molecular-weight polyolefin intermediates formed from the polyolefin host polymer,
• wherein the transition-metal carboxylate, the hindered phenolic primary antioxidant, the phosphite secondary antioxidant, and the bio-assimilation promoter package are dispersed together in the single storage-stable pelletized masterbatch before the masterbatch is let down into the polyolefin host polymer.