Influence of PMMA particle size control on the transmittance of PMMA/tempo-oxidized cellulose composites

Cellulose is a class of biopolymers that prominently contributes to developing lightweight, eco-friendly, and biodegradable plastics. Among them, nanofibrillated cellulose (NFC) is one of the most interesting due to its mechanical behavior. Mixing it with synthetic plastic such as poly(methyl methacrylate) (PMMA) reduces synthetic polymer usage, agro-industrial residue and develops fiber-reinforced composites. NFC was prepared from residual biomass and oxidized with TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical). Herein, NFC was incorporated (25, 50 and 75 wt%) in a colloidal emulsion of PMMA, with PMMA particle size control (50 and 175 nm). The investigation of this system on the PMMA/NFC transparency was addressed here. FTIR and SEM demonstrated effective incorporation of NFC and interaction with the PMMA. The increment of NFC increased the water contact angle and improved film transparency. Paired with PMMA particle size control, particularly at 50 nm, this favored composite transparency, becoming close to or even greater than pure NFC. Graphical abstract