Mechanical, frictional and thermal behavior of biopolymer blended composites reinforced with biodegradable neem short fibers

• Neem short fibers had higher properties, due to fiber impregnation, wettability and adhesion of wheat gluten. • Density of the fabricated samples showed very less deviation than the theoretical one. • Presence of crystallinity resulting in the stronger mating thus led to higher mechanical properties. • The wear rate was higher at the load 14.73 N and velocity at 1.5 m/s. • The weight loss after its crystallinity decline state begins at temperature between 387-411° C. The interest in utilizing the plant based cellulosic materials and biopolymers for developing the light weight composites for various commercial and industrial application has rapidly increased. The traditional composites made using the synthetic fibers, petroleum derived materials create the several drawbacks like environmental pollutions, handling difficulties due to higher weight, non-recyclability and high cost to manufacturing. So, the present work developed the nine different bio composites by adding the short neem fiber randomly with the blended wheat gluten (WG) and Polyhydroxybutyrate (PHB) biopolymer matrix. The effect of neem fiber and biopolymer constituent in laminate and blending ratio of WG and PHB bio polymers were investigated through the tensile, flexural, impact, hardness, wear, thermogravimetric analysis and microstructural analysis according to the ASTM standard. The result from the above test indicate that the neem short fibers reinforced randomly with blended WG/PHB biopolymer composites had attained higher mechanical properties, wear and heat-resistant capability due to better fiber impregnation, wettability and adhesion characteristics of wheat gluten. The density of the fabricated samples showed very less deviation than the theoretical one. The SEM micrographs confirm the increased surface area of the neem fiber and presence of crystallinity at the interface region resulting in the stronger mating thus led to higher mechanical properties. The tensile strength shows 48-56 MPa for 30NWP composites (186% higher than 10NWP) and 32-40 MPa for 20NWP composites (64% higher for than 10NWP). There is 21-38 % increase in the flexural strength of 20% neem fiber composites than the 10% neem composites, where as it is increased to 35-49 % for 30% neem composites. Impact strength of 30% neem fiber composites found to be 21-31.5 KJ/m2. The wear rate was higher at the load 14.73 N and velocity at 1.5 m/s. The weight loss of the biopolymer samples, following the onset of crystallinity decline, begins at a temperature between 387-411°C. The result showed the well-organized material properties and good substitutional to the traditional materials.