Optimization of graphene nanoplatelets dispersion and nano-filler loading in bio-based polymer nanocomposites based on tensile and thermogravimetry analysis

The incorporation of graphene nanoplatelets (GNPs) has attracted massive attention in polymer nanocomposite production. In this work, GNPs reinforced nanocomposites of liquid natural rubber (LNR) toughened poly (lactic acid) (PLA)/poly (aniline) (PANi) were fabricated through melt-mixing using internal mixer. The effects of ultrasonic treatment period, mixing rotor speed and GNPs loadings in PLA-LNR/PANi was investigated. A premix ultrasonication of LNR/PANi with GNPs for 1 h was found to be the most effective period as compared to the longer sonication time. The best melt-mixing of the materials was achieved at 100 rpm, in accordance to the tensile properties as well as homogeneous dispersion and distribution of nano-filler as shown in thermogravimetry analysis. Results revealed that the optimum loading was found at 0.4 wt.% of GNPs with excellent enhancement in tensile strength (25 MPa), tensile modulus (1188.9 MPa) and thermal stability of the nanocomposite, as proven by ANOVA statistical analysis.