Role of lignin nanoparticles in UV resistance, thermal and mechanical performance of PMMA nanocomposites prepared by a combined free-radical graft polymerization/masterbatch procedure

In the present work, the preparation of lignin nanoparticles (LNP) reinforced Poly(methyl methacrylate) (PMMA) nanocomposites, obtained by combining solvent-free radical polymerization, micro extrusion and hot press methods through a masterbatch approach, was reported. Results from Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and Gel Permeation Chromatography (GPC) evidenced the successful grafting of LNP on MMA, confirmed by the higher glass transition temperatures observed by DSC in LNP grafted PMMA (PMMA-g-LNP) systems. Microstructural characterization proved good LNP dispersion in PMMA, achieved by means of the adopted masterbatch procedures. Furthermore, results from optical, thermal and mechanical characterization of the resulted PMMA nanocomposites confirmed improved hardness values, enhanced UV resistance, better thermal and scratch resistance for PMMA/LNP nanocomposites, opening the possibility of using these systems in many different sectors, such as automotive, flooring, acrylic glasses and lenses.