Impact of interfacial adhesion on the microstructure and property variations of biocarbons reinforced nylon 6 biocomposites

This work systematically demonstrates the effect of biocarbon surface chemistry on the properties of nylon-biocarbon biocomposites and that they can be designed for specific applications by engineering the biocarbon surface through pyrolysis. Miscanthus fibers pyrolyzed at ∼500 °C (B1) and ∼900 °C (B2) were used to reinforce nylon 6 at 20 wt.% loading. The composite containing B1 (NB1) exhibited increased tensile and flexural strengths by 19.5% and 31% respectively while the composite containing B2 (NB2) exhibited significantly lower aforementioned properties than those of NB1. The impact strength of NB2 was unchanged while that of NB1 was diminished by 32%. The property variations of the composites were attributed to the difference in interfacial adhesion between the biocarbons and nylon due to the biocarbons' different surface functionalities. Complex and shear-viscosities showed greater restriction of the nylon chains in NB1 stemming from stronger interaction between B1 and nylon.