Parametric Study on Bamboo Fibre Reinforced Polyester Composites: Role of Soaking Time, Catalyst Ratio, and Alkali Treatment

Bamboo fibres were treated with varying conditions of soaking time, accelerator/catalyst ratio and NaOH treatment  concentration. These parameters play a major role in determining the performance properties of the developed polyester  composite for structural applications. The reinforced 10 – 40 wt% bamboo fibre–polyester composites were fabricated  using the hand layup technique and the mechanical properties (tensile, hardness, impact and flexural strength) were  evaluated using a universal testing machine and Charpy impact tester. Due to the varying conditions of the parameters,  the Taguchi L16 orthogonal array was employed to design the experiment. Microstructural analysis was conducted using  a scanning electron microscope to study the surface morphology of the composite. The mechanical properties of the  developed bamboo fibre reinforced polyester composite were evaluated considering the bamboo fibre (BF), soaking  time (ST), accelerator/catalyst ratio (ACR) and NaOH treatment concentration. The study revealed that wt% of the  bamboo fibre improves the properties at 30 - 40 wt% as 30 wt% attained the optimum for hardness (121.16 Hv) and  flexural strength (93.99 MPa) while 40 wt% for tensile (78.53 MPa) and impact strength (4.85 KJ/m2). Soak time  enhanced the properties within 2 – 3 hrs with an optimum of 2 hrs for tensile strength (77.68 MPa) and 3 hrs for impact  (5.52 kJ/m2) and flexural strength (89.04 MPa). The ratio of accelerator/catalyst displayed optimum at 1.2 mix for  hardness (119.54 Hv), flexural (93.61 MPa) and tensile strength (70.34 MPa). High volume of accelerator to catalyst  mix leads to brittleness, debonding of the polymer composite. Lower NaOH treatment concentration achieved the  optimum for the mechanical properties. However, higher NaOH concentration degrades the fibres and reduces their  strength and stiffness, ultimately decreasing the composite properties. This study provides the relationship amongst the  process parameters and their influence on the mechanical properties of bamboo fibre reinforced polyester composite for  structural applications.