Improving the performance of hemp hurd/polypropylene composites using pectinase pre-treatments

The potential for using pectinase as a pretreatment to improve the properties of hemp hurd for use in a hemp/polypropylene composite was compared with the addition of a silane coupling agent. Pectinase pre-treatment reduced pectin levels in the hemp hurd (p = 0.0014) and this reduction was associated with improved tensile strength, modulus of rupture, modulus of elasticity and resistance to water uptake (p < 0.0001). Pre-treatment had no consistent effect on thickness swell. Addition of a coupling agent to non-modified hemp/polypropylene panels produced similar improvements to panel properties (p < 0.0001) and also markedly reduced thickness swell (p = 0.01). The results indicate that pectinase pretreatment can enhance panel strength properties but did not affect moisture behaviour.