The Effect Of Immersion On The Post-Impact Bending Strength Of A Polyurethane Rigid Foam Sandwich Composite With Bamboo-Fiberglass Woven Reinforcement

Abstract

The development of environmentally friendly composite materials is important because it is a global demand. However, using natural materials does not rule out the possibility of a decrease in quality during use in a wet environment and in conditions of impact defects. This paper analyzes the post-impact bending strength of sandwich composites with woven bamboo reinforcement after being immersed in seawater. Sandwich composites are made by laminated polyurethane rigid foam sheet with polyester resin and bamboo-fiberglass woven hybrid reinforcement. To provide defects in the sandwich composite, dropweight impact was carried out, then it was immersed in seawater and a bending test was carried out. The highest average bending strength of sandwich composites occurs in formations with a higher amount of fiberglass. The performance of maintaining post-impact bending strength is better in composites with more bamboo laminate formations, the decrease in post-impact bending strength is only 2.6%. The post-impact bending strength of sandwich composites in wet conditions has a lower value than in dry conditions. The longer the immersion of the sandwich composite in seawater after impact, the smaller the bending strength.