A Study on Biocomposites from Recycled Newspaper Fiber and Poly(lactic acid)

Abstract

Recycled newspaper cellulose fiber (RNCF) reinforced poly(lactic acid) (PLA) biocomposites were fabricated by a microcompounding and molding system. RNCF-reinforced polypropylene (PP) composites were also processed with a recycled newspaper fiber content of 30 wt % and were compared to PLA/RNCF composites. The mechanical and thermal−mechanical properties of these composites have been studied and compared to PLA/talc and PP/talc composites. These composites possess similar mechanical properties to talc-filled composites as a result of reinforcement by RNCF. The tensile and flexural modulus of the biocomposites was significantly higher when compared with the virgin resin. The tensile modulus (6.3 GPa) of the PLA/RNCF composite (30 wt % fiber content) was comparable to that of traditional (i.e. polypropylene/talc) composites. The DMA storage modulus and the loss modulus of the RNCF−PLA composites were found to increase, whereas the mechanical loss factor (tan δ) was found to decrease. Differential scanning calorimetry (DSC) thermograms of neat PLA and of the composites exhibit nearly the same glass transition temperatures and melting temperatures. The morphology evaluated by scanning electron microscopy (SEM) indicated good dispersion of RNCF in the PLA matrix. Thermogravimetric analysis (TGA) thermograms reveal the thermal stability of the biocomposites to nearly 350 °C. These findings illustrate that RNCF possesses good thermal properties, compares favorably with talc filler in mechanical properties, and could be a good alternative reinforcement fiber for biopolymer composites.