Biochar and Its Size Effects on Polyamide 6/Biochar Composites

Abstract

Biochar was used as a filler material for polyamide 6 (PA6) composite and the effect of particle size on the composite properties were analysed. Large particles, when prepared by manual (median particle size ~ 84 μm) and mechanical grinding (~ 41 μm), caused a reduction in tensile, flexural and impact strength, but did not strongly affect the Young’s or flexural modulus. However, using strongly reduced particle sizes after ball milling the biochar for 6 (~ 3.8 μm), 12 (~ 3.2 μm) and 24 (~ 2 μm) hours respectively leads to improved mechanical properties. Atomic Fore Microscopy (AFM) based Quantitative Nanomechanical Property Mapping (QNMP) revealed improved bonding of the ball milled particles with the polymer due the increased particle surface area. The addition of biochar also causes an increase in heat deflection temperature (HDT) and crystallinity compared to the neat polymer.