Effect of pressing time on the physical, mechanical, and morphological properties of composite made of gmelina bark and recycled polypropylene

• Published in: Bioresources 2024-11, Vol.19 (4), p.715
• Main Authors: Sutrisno, Alamsyah, E. M., Suheri, A
• Format: Article
• Language: English
• Subjects: Compatibilizers; Composite materials; Density; Lignocellulose; Maleic anhydride; Mechanical properties; Microorganisms; Mixtures; Modulus of elasticity; Modulus of rupture; Moisture content; Morphology; Pellets; Per capita; Physical properties; Polyethylene; Polymers; Polypropylene; Polyvinyl chloride; Pressing; Raw materials; Room temperature; Steel plates; Tensile strength; Variance analysis; Water absorption; Water content
• ISSN: 1930-2126
• DOI: 10.15376/biores.19.4.7154-7165

The effects of pressing time were evaluated relative to the physical, mechanical, and morphological properties of flat-pressed composites made from Gmelina arborea bark and recycled polypropylene (RPP). Bark powder (5% moisture content) was mixed with RPP pellets in a weight ratio of 40:60 with added maleic anhydride (MAH) as compatibilizer. The materials were mixed in a rotary blender for 15 min at speed 80 rpm until homogeneous. The mixture was heated from 175 to 200 °C until RPP pellets were completely melted and then cooled to room temperature. Afterwards, the mixture was made into powder and molded using a steel plate mold at 175 to 200 °C and pressure of 30 kg/cm2 for 2, 4, and 6 min to a targeted density of 1.0 g/cm3. The tested physical properties were covered density, moisture content, water absorption, and thickness swelling. The mechanical properties modulus of elasticity (MOE) and modulus of rupture (MOR), tensile strength parallel to length of panel were also examined. Research results showed that the properties were significantly affected by pressing time and it can be concluded that the optimum condition was obtained at 4 min of pressing.