Preparation and properties of acacia sawdust/UPR composite based on recycled PET

Polyethylene therephthalate (PET) waste bottles had been depolymerized
by glycolysis and reduced to its monomer and dimer. The glycolysed product was used to
produce unsaturated polyester resin (UPR). DSC and FTIR analysis were conducted on
the resin and the glycolysed product. The resin was then mixed with sawdust (acacia) to
produce the sawdust/UPR composite based on recycled PET. The effect of surface treatment and filler loading on mechanical properties of the composites were studied. The results showed that the modulus of both tensile and flexural increased with increasing filler contents whereas the strength decreased. This was overcome by treating the sawdust fillers with 10% sodium hydroxide (NaOH). The tensile, flexural, hardness and water absorption tests showed that the alkali treatment has enhanced the adhesion between the sawdust and the UPR matrix.