(121c) Biobased Composites for Improved Mechanical Performance and Recyclability

In this study, the mechanical properties of polylactic acid (PLA) and PLA-based composites were reinforced with lignin based nanocarbons synthesized using Joule-heating method. Three different blending methods were investigated, which include direct blending of PLA and nanocarbons, pre-mixing PLA and soybean based hyperbranched elastomers (namely SBCP-B) followed by blending the PLA composite with nanocarbons, and one-step blending of PLA, soybean based hyperbranched elastomers and nanocarbons. The effect of fabrication condition of nanocarbons and the mass loading of nanocarbons in composites were investigated. The analysis results showed that blending 0.1wt% of nanocarbons could increase tensile strength of PLA from 75.96 MPa to 85.98 MPa without affecting tensile modulus and strain of the material. Adding 0.5% of nanocarbons enhanced the performance of SBCP-B by increasing tensile strength from 68.72 MPa to 71.78 MPa, tensile modulus from 5.43 MPa to 5.59 MPa, and strain from 48.59% to 55.91%. When PLA, soybean based hyperbranched elastomers, and 0.5%load nanocarbons were blended in one batch, tensile strength of 82.61 MPa, tensile modulus of 6.08 GPa, and strain of 7.72% were obtained.