Comparison of the effect of commercial coupling agents on the mechanical properties and dimensional stability of wood-fibre plastic composites

Mechanical properties and dimensional stability of wood fibre plastic composites containing different commercial coupling agents (PP-g-MAH) was studied. Polypropylene and two types of wood fibres, particle board chips and cutter chips from thermal treated wood were used in the composites. The grade of the coupling agent has an effect on the achieved mechanical properties of the composites. The effects were similar for both types of fibres used. The 3 w-% addition of the coupling agents improves more the impact strength properties than the 2 w-% addition. The wood-fibre plastic composites proved to be dimensionally stable. The same coupling agent that increased the mechanical properties of the composite, had also a positive effect on the dimensional stability of the composite. The strength properties of the composite materials are improved when the interaction between the polymer and wood fibres are improved. The improvement of the interaction increases also the dimensional stability