Properties investigation of recycled polylactic acid reinforced by cellulose nanofibrils isolated from bagasse

In this research, an industrial‐scale approach was developed for preparing bio‐nanocomposites from recycled polylactic acid (rPLA) and cellulose nanofibrils (CNFs). In this regard, several steps were conducted consisting of extracting CNFs, preparing CNF/rPLA master batch, and melt compounding which was finally followed by compression molding. The influence of adding CNFs on rPLA properties was investigated by morphological, mechanical, thermo‐mechanical, and degradability studies. Images from scanning electron microscopy (SEM) revealed an increase in the fracture surface roughness of rPLA after adding CNFs. In addition, compared to unreinforced rPLA, the modulus and strength of bio‐nanocomposites containing 3 wt% CNFs were enhanced from 527.5 and 23.9 MPa to 716.5 and 32.6 MPa, respectively. Other mechanical properties including elongation at break and work of fracture were decreased by 35.5 and 33% at this CNF percentage. Furthermore, the storage modulus, obtained from dynamic mechanical analysis (DMA), was significantly improved from 1,024 to 8,214 MPa after adding 3 wt % CNF. Similarly, at this CNF percentage, glass transition temperature (T_g) was enhanced from 59.5 to 64°C. According to biodegradation study, the highest biodegradability resistance was also obtained for bio‐nanocomposite containing 3 wt % CNF. POLYM. COMPOS., 39:3740–3749, 2018. © 2017 Society of Plastics Engineers