Performance and properties of wood/polypropylene panels as affected by wood aqueous extraction
Ibrahim Aref1; Hamad Al-Mefarrej1 Ramadan Nasser1,2
Corresponding author: nasser67@ksu.edu.sa (Ramadan Nasser)
1 Plant Production Department, College of Food and Agriculture Sciences, King Saud University, Saudi Arabia
2 Forestry and Wood Technology Department, Faculty of Agriculture (Al-Shatby), Alexandria University, Egypt
ABSTRACT
The manufacturing of wood/polymer composites (WPCs) by compounding wood particles with plastic at temperatures above their melting point may cause the thermal degradation of the wood, which can lead to undesirable properties, including odor, discoloration and a degradation of the mechanical properties of the panels.1 This study was conducted to investigate the effect of a particle pre-treatment (cold water soaking and hot water extraction) on the performance and properties of wood/PP composite panels made of four lignocellulosic materials and polypropylene, PP, (50/50 by weight). Composites filled with pretreated and untreated particles of three wood species and date palm midrib fronds were manufactured using a melt blending technique followed by compression molding. The physical, mechanical and dimensional stability properties of the WPC panels were evaluated. The interaction between the wood and the PP was characterized by FT-IR. All the composites showed a similar spectrum, but a few additional peaks appeared relative to neat PP in five regions. The results indicated that the four species are significantly different in all chemical constituents. Pretreating the wood particles by either cold or hot water resulted in significant improvements in the compatibility of each wood species with PP, as observed by an increase in the mechanical properties and by a decrease the water uptake and thickness swelling of the composites. An enhancement in strand color, a decrease in smoke and excessive odor during the compounding process were also observed, which resulted in an enhancement in the performance of the panels produced, particularly for the date palm midrib fronds.
Keywords
Wood/polymer, compounding, wood, composites, pretreatments, FTIR, water uptake, thickness swelling.