Effect of stacking sequence on mechanical properties and moisture absorption characteristic of hybrid palf/glass fiber composites

Abstract

Applications of natural reinforcements such as pineapple leaf fiber (PALF) have increased considerably due to unlimited resources from the nature. Hybridization of fiber reinforced composites promoted various advantages such as low weight, low cost, biodegradable and eco-friendly products having unique properties. This study aims to assess the effect of stacking sequences on the moisture absorption characteristics and mechanical properties of hybrid PALF (P) and glass fiber (G) reinforced polymer composites. The accelerated moisture absorption test as well as flexural and tensile experiments were conducted on the pure PALF and the hybrid PALF/glass fiber reinforced epoxy composites with three different stacking sequences of PGPG, GPPG and PGGP. The fractured surface of the specimens was analyzed using a scanning electron microscope (SEM). The Fickian diffusion theory was applied to characterize the composite moisture absorption behavior. Results indicated that the pure PALF laminated composite absorbs a higher percentage of moisture than the hybrid composites, which causes the higher degradation of the mechanical properties of pure PALF composite compared to the hybrid composites. The stacking sequences of the PALF and the glass fiber have significant influence on the diffusion rate of water into the composites. The results of the tension and the flexural experiments showed that the hybrid composites have superior mechanical properties compared to the non-hybrid fiber composite with the percentage increases of the flexural and the tensile strength up to 119 % and 153 %, respectively. The hybrid composite with alternate stacking configuration, i.e. PGPG, revealed the highest flexural and tensile strengths of 170.13 MPa and 119.21 MPa, respectively. In addition, the SEM observation displayed better interfacial bonding between the fiber and the matrix in the hybrid composite with PGPG stacking sequence compared to the other specimens.