Green polymer chemistry: Recent developments

Abstract

This article briefly reviews research developments on "green polymer chemistry" and focuses on the studies recently performed by our group and related work by some other groups. The green character of polymer synthesis has been viewed from the standpoint of starting materials, polymerization catalyst, reaction solvent, and polymer recycling. Starting materials employ biobased renewable resources such as lactic acid (LA), itaconic anhydride (IAn), succinic anhydride, 1,4-butane diol, etc. Green catalysts include enzymes like lipase and protease. Green solvents are water, supercritical carbon dioxide, and ionic liquids; in particular, water is often used for emulsion systems. From LA and IAn, methacyloylpolymerizable macromonomers were derived and their copolymerization with a (meth)acryroyl monomer in miniemulsion produced a graft copolymer having LA graft chains. The copolymers are classed as bioplastics from their biomass content ( 25 wt%) and are applicable for coatings. LA chain-containing comb polymers and a star-type polymer were prepared, the latter being currently employed as a coating material. The mechanism of catalysis of the enzymes in the oligomerization of LA alkyl esters was examined to reveal direct evidence that a deacylation step determines the enantioselection. Lipase catalysis was utilized for a polymer recycling system © Springer-Verlag Berlin Heidelberg 2013.