Renewable Biobased Polymeric Materials: Facile Synthesis of Itaconic Anhydride-Based Copolymers with Poly(L-lactic acid) Grafts

This paper reports a new synthesis of biobased polymers by using itaconic anhydride (IAn) and lactic acid (LA) as renewable starting materials. Poly(lactic acid) (PLA)-graft copolymers were synthesized via two approaches. First, the macromonomer approach utilized IAn for Sn-catalyzed synthesis of PLA-containing macromonomers (IAn-PLA Macro). The macromonomer was radically copolymerized with n-butyl methacrylate (BMA), n-butyl acrylate (BA), methyl methacrylate (MMA), and ethyl methacrylate (EMA) to give efficiently graft copolymers (PLA-Graft copolymer (I)) with molecular weight M-n up to 1.61 X 10(5) having biomass content higher than 34 wt %. Second, the copolymer approach employed first IAn as comonomer for radical copolymerization with BMA, giving rise to IAn-BMA copolymer with M-n higher than 5.76 X 10(4). Then, Sn-catalyzed grafting of PLA onto IAn moiety of the copolymer produced PLA-Graft copolymer (II) with Mn higher than 5.88 X 10(4), showing biomass content >= 29 wt %. In addition, radical homopolymerization of IAn was examined to give polyIAn. By using these two approaches employing IAn as a starting reactive material, PLA-graft copolymers were obtained as biomass-plastics. Properties of PLA-Graft copolymers (I) were also examined, which revealed possible applications for coatings and plastics. Furthermore, the IAn-containing graft copolymers will be a convenient starting biomass polymer having reactive IAn moiety in the main chain for further grafting or various functional group-introducing reactions.