Experimental Determination of the Mechanical Behavior of Glass Fiber Reinforced Polypropylene Composites

Abstract

Thermoplastic composites have been widely used in structural and engineering applications, due to their high specific strength and stiffness, high strain to failure, better impact strength, shorter processing cycle time, infinite shelf life, and recyclability. This paper discusses the influence of the forming pressure and coupler concentration on the mechanical behavior of glass fiber reinforced polypropylene composite laminates. The Design of Experiments’ (DOE) full factorial approach was adopted for conducting the composite laminate fabrication experiments. The thermoplastic composite laminates were fabricated in a hot compression molding machine, using the film stacking technique. This is an innovative approach to develop thermoplastic composite laminates, using the available low cost raw materials, instead of high end prepreg materials. As per the ASTM standard, the tensile and flexural tests were carried out, in order to evaluate the influence of the parameters on the mechanical behavior of the composite laminates. The Tensile and flexural strengths of the thermoplastic composite laminates were the responses measured to identify the most influencing parameter. The experimental results show that the increase in forming pressure and coupler concentration initially increases both the mechanical properties, and then decreases the properties of the composite laminates. Compared to the coupler concentration, the forming pressure greatly improves both the tensile and flexural properties. Using the Scanning Electron Microscope (SEM), a morphological analysis was carried out to observe the bonding between the matrix and reinforcement.