Polyurethane (PU)—oil palm empty fruit bunch (EFB) composites: the effect of EFBG reinforcement in mat form and isocyanate treatment on the mechanical properties

Abstract

Polyurethane (PU)-oil palm empty fruit bunch (EFB) composites have been produced. The PU matrix employed consisted of diphenyl methane diisocyanate (MDI) and polyethylene glycol (PEG) with a molecular weight of 200. EFB fibres were used in the form of mats. The fibres were treated with two types of isocyanate: hexamethylene diisocyanate (HMDI) and toluene diisocyanate (TDI). In general, the employment of EFB in mat form has produced PU-EFB composites with acceptable properties. The properties of the composites were believed to be predominantly influenced by the type of bonding produced. In general, the composites with isocyanate treated fibres showed superior tensile and flexural properties than those without treatment. These were believed to be attributed to the additional reaction sites in the form of urethane functional groups produced as the result of NCO reactions with OH of EFB prior to subsequent interaction with PU/PEG mixtures. The relatively superior properties of composites with HMDI treated fibres over those treated with TDI were probably due to the longer chain of the former, which render it more accessible to the reaction with OH of PEG and also to its increased capability in absorbing more energy transferred from the matrix.