The need to have composite materials that are renewable has lead to materials scientists researching on natural fibres. To minimize environmental pollution research into rice husk has been on for a period of time now. In this research cashew nut resin reinforced rice husk composite was fabricated at different particle sizes and different filler loading. The present study reveals that both filler loading and particle size can affect the tensile strength, young modulus, strain at failure, flexural strength, and impact strength. As the % filler content increases all particle sizes (400µm, 600µm and 800µm) shows a quadratic relationship except % elongation at failure which tends to be linear at 400µm. As particle size increases all % filler content shows quadratic relationship which tends to be linear. As particle sizes increases impact strength for 10 and 30% shows a linear equation while 20% shows a quadratic relationship which tends to be linear. In general, RH/CNSR composite could be considered as a potential source of low cost, natural fibre for composites.

Mechanical properties (tensile strength and modulus) of Chitin Whiskers fibre-reinforced poly(acrylic acid) with different fibre loading and different gauge lengths are compared with theories of reinforcement. The addition of random oriented Chitin Whiskers to poly(acrylic acid) matrix increased in tensile strength and elastic modulus of the composite. There was a steady increase in tensile stress and Elastic modulus within the volume fraction range investigated. The properties of the composite at different gauge lengths were studied. Within the same volume fraction, the tensile stress decreases as the gauge length increases. It is the reverse for the Elastic Modulus. Irrespective of filler loading and the theoretical modelling equations the tensile stress can be predicted at 40 mm gauge length. For the Elastic Modulus, the prediction of the property varies within the gauge lengths investigated. At higher filler loading, a smaller gauge length is required to predict the Elastic modulus. The comparative study between the tensile stresses obtained by experiment and selected theoretical models showed that the Parallel and Series models of the Rule of Mixture produced more accurate prediction, followed by Halpin-Tsai and modified Halpin-Tsai models. Guth's model was the least as the percentage deviation from the experimental data was very high when predicting the Elastic modulus. The density of the nanocomposite films were 1.08g/cm3, 1.023, and 1.024g/cm3 respectively, for 3%, 6%, and 9% weight filler and were in agreement with the theoretical data.

Four PA6/graphite (G) composites systems were made. Two using in situ polymerisation equivalent in mixing strain and two systems melt extrusion of equivalent processing strain. The effective modulus of the carbons, room temperature storage modulus and storage modulus at 80 ⁰C were evaluated. The composite/unfilled PA6 ratios at E25 and that at E80 for the in situ polymerised system IG 40/10 are 1.37 and 1.63, respectively. For the in situ polymerised system IG 20/20, the same were 1.96 and 2.28, respectively. For the melt-extruded systems, G 100/6 had the best E25 ratio of 1.67 and E80 of 2.03, whereas the same for G 200/3 system were respectively 1.87 and 2.64. While the better storage modulus properties exhibited by IG 20/20 in the in situ polymerised system is associated with a better filler connectivity network that enhanced heat dissipation. The better values shown in the G 200/3 melt-extruded system is associated with the lesser extrusion, which significantly reduced the tendency to thermal decay. Effective modulus for the in situ polymerised systems IG 40/10 and IG 20/20 were 7.5GPa and 8.9GPa while that of melt-extruded systems G200/3 and G100/6 tallied at 8.2 GPa.