Karakteristik Papan Komposit Plastik dari Campuran Serbuk Gergajian Kayu Mahoni (Swietenia mahagoni) dan Limbah Plastik Polipropilena

Abstract

Polypropylene plastic waste and mahogany sawdust were utilized to produce wood–plastic composites (WPCs) with different material ratios and the addition of maleic anhydride (MAH). The ratios tested were 60:40, 70:30, and 80:20 (polypropylene:wood flour) to evaluate the effect of increasing plastic content on board properties. MAH was applied as a coupling agent to enhance bonding between plastic and wood particles. The objective of this study was to analyze the characteristics, the effect of material ratios, the addition of MAH, and their interaction on the physical and mechanical properties of WPCs. The composites were manufactured by mixing polypropylene and mahogany sawdust according to the specified ratios, with 5% MAH addition, followed by hot pressing at 180°C for 30 minutes. Data were analyzed using a two-factor completely randomized design with three replications and DMRT at the 5% level. The results showed that the best physical properties were obtained at the 80:20 ratio with 5% MAH, with a density of 0.87 g/cm³, moisture content of 0.44%, water absorption of 6.14%, and thickness swelling of 1.95%. The best mechanical properties were recorded at the 80:20 ratio without MAH, with a modulus of elasticity (MOE) of 18,491.1 kgf/cm² and modulus of rupture (MOR) of 156.43 kgf/cm². The highest internal bond (IB) strength was found at the 60:40 ratio with MAH (2.39 kgf/cm²). Scoring based on JIS A 5908-2003 and FAO (1966) standards indicated that the 80:20 ratio with MAH provided the best overall performance with a score of 21. Statistical analysis revealed that MAH significantly affected most physical properties and IB (p < 0.05), the material ratio significantly affected MOE and MOR, and their interaction significantly influenced moisture content, water absorption, thickness swelling, and MOR.