Comparative effects of different coastal weathering on the thermal, physical, and mechanical properties of rubberwood–latex sludge flour reinforced with polypropylene hybrid composites

The influence of coastal weathering in tropical countries is a concern in terms of applications of wood-plastic composites (WPCs). Therefore, developing the WPCs into hybrid composites for increasing the resistance to the coastal climate needs further investigation. The current work studies the effects of different coastal climates (Gulf of Thailand and Andaman Sea), exposure times, and latex sludge contents on the properties of rubberwood-latex sludge flour reinforced with polypropylene hybrid composites. The hybrid composites were manufactured with a twin-screw extruder for mixing and a compression molding machine for forming. The results revealed that the hybrid composites weathered for 12 months significantly (α = 0.05) decreased the modulus of rupture, modulus of elasticity, screw withdrawal strength, and hardness with a maximum reduction of 218.6%, 207.4%, 84.2%, and 11.4%, respectively. However, adding the latex sludge flour of about 25 wt% increased crystallinity degree and thermal stability as compared with the WPCs filling 50 wt% rubberwood flour. The hybrid composites weathered under the Andaman Sea exhibited less loss of all the mechanical properties than that weathered under the Gulf of Thailand. It is therefore suggested that the hybrid composites added to the latex sludge waste have the potential to be used to produce the engineering products that were applied under the coastal climates.