In a second, apparently unrelated study at UiTM's Shah Alam campus, Mohd Iqbal Misnon and his collaborators in the departments of textile technology and biocomposite technology tested hybrid composites made of rubberwood, coconut shell, and woven cotton or polyester textile fabrics. Their intent was to find out how reinforcement provided by textile fabrics affects biocomposites.
Several different hybrid composites were created, with two, three, or four layers of cotton or polyester fabric. The control samples were unreinforced hybrid composites. The team conducted flexural strength, impact strength, water absorption, and thickness swelling tests.
The flexural strength and flexural modulus of fabric-reinforced hybrid composites improved compared to the control sample. The flexural modulus of composites reinforced with four layers of fabric tended to decrease slightly. Fabric also delivered better impact damage tolerance, which increased with layer count.
Since the polyester fabric did not adhere well to the rubberwood and coconut shell mixture, it was not as strong as the cotton fabric-reinforced versions. The researchers said that, if its adherence was improved, the polyester hybrid composite's flexural strength and impact properties would likely improve.
The hybrid composites reinforced with cotton had better flexural but lower-impact strength than the polyester-reinforced composites. Composites reinforced with both fabric types had lower water absorption and higher values of thickness swelling than the control sample.