Grafting Lignin with Bioderived Polyacrylates for Low-Cost, Ductile and Fully Biobased Polylactic Acid Composites

It has been always attractive to design low-cost, ductile and fully biobased polylactic acid (PLA) composites based on industrial waste lignin for promoting its practical applications in industry. Unfortunately, existing material strategies often lead to poor processability and low ductility because of weak interfaces between lignin and PLA. Herein, we report a fully biobased functionalized lignin (Lig-g-P(LMA-co-THFMA, or Mlignin) by chemically grafting two bioderived monomers, lauryl methacrylate (LMA) and tetrahydrofurfuryl methacrylate (THFMA) via free radical polymerization. Mlignin exhibits much better melt-processability and formability with PLA during melt processing as compared with pristine lignin. Because of improved interfacial adhesion, Mlignin can uniformly disperse within the PLA matrix in a submicron phase size, leading to a “sea-island” structure. As a result, the addition of 20wt% Mlignin increases the ductility by 1600% (from 12% to 204%) and the toughness by ~1100% from 4.4 to 54.6 MJ ...