Farah Atiqah Abdul Azam, Nishata Royan Rajendran Royan, Nor Yuliana Yuhana,
Nabilah Afiqah Mohd Radzuan, Sahrim Ahmad and Abu Bakar Sulong *
Abstract: In this study, a biodegradable, cheap and durable recycled high-density polyethylene
(rHDPE) polymer reinforced with rice husk (RH) fibre was fabricated into a foam structure through
several processes, including extrusion, internal mixing and hot pressing. The effect of filler loading
on the properties of the foam and the influence of RH surface treatments on the filler–matrix
adhesion and mechanical properties of the composite foam were investigated. The morphological
examination shows that 50 wt.% filler content resulted in an effective dispersion of cells with the
smallest cell size (58.3 μm) and the highest density (7.62 × 1011 sel/cm3). This small cell size benefits
the mechanical properties. Results indicate that the tensile strength and the Young’s modulus of the
alkali-treated RH/rHDPE composite foam are the highest amongst the treatments (10.83 MPa and
858 MPa, respectively), followed by UV/O3, which has shown considerable increments compared
with the untreated composite. The flexural and impact tests also show the increment in strength for
the composite foam after chemical treatment. Although the UV/O3 surface treatment has minor
influence on the mechanical enhancement of the composite foam, this method may be a reliable
surface treatment of the fibre-reinforced composite.