Impregnation of white pine wood with unsaturated polyesters to produce wood–plastic combinations

Abstract

SYNOPSISTwo unsaturated polyester resins based on poly ( 1,2 propylene-maleate-phthalate) ( P E 1 ) , and poly (oxy-diethylene-maleate-phthalate) ( PE2 ) were used for the impregnation of oven-dried white pine wood samples in admixture with styrene (S) . Curing was affected by the initiator-heat technique by either using 0.1-0.2% by weight of benzoyl peroxide (Bz,O,) , or 1% by weight of methyl ethyl ketone peroxide (MEK) . It was found that the use of PEl/S mixture resulted in the formation of wood-plastic combinations (wpc) with higher percent retention and higher percent polymer loadings than those obtained by the impregnation of wood samples with P E 2 / S mixtures. The use of different swelling solvents including ethanol, acetone or chloroform, did not influence the percent retention or polymer loadings of wpc for either P E l / S or P E 2 / S mixtures. Physical tests performed on wpc showed that compression, hardness, static bending were generally enhanced, water absorption was decreased, and dimensional change was retarded to different extents for both polyesters used, but no permanent stabilization was attained.

Influence of some additives on the performance of wood flour/polyolefin composites

“…To determine water absorption and dimensional changes,23 specimens 2 × 2 × 3 cm 3 were used. The samples were oven‐dried at 105°C for 4 h, weighed, and then submerged in water for different time intervals.…”

Wood-Polymer Composites

“…Electron-beam irradiation was used to make WPCs of beech sapwood veneers with styrene, MMA, acrylonitrile, butyl acrylate, acrylic acid, and unsaturated polyesters (Handa et al, 1983;Doss et al, 1991;Şolpan & Güven, 1995;1996;Tang & Xu, 2004). Increasing the wood moisture content has a positive effect on electron curing.…”

“…19 and Fig. 26); and the filling reagents could be most of vinyl monomers and functional monomers, such as GMA, EGDMA, PEG(200)DMA and so on (Keskin et al, 2008;Rodrigues et al, 2004;Roussel et al, 2001;1991;WallstroÈm & Lindberg, 1999) For the bulking treatment, one way is the bulking agents in liquid form directly move into and thus swell the cell wall; another way is the bulking agents as nonpolar or weak polar molecules swell the cell wall by diluting in polar solvents, such as methanol acetone, tetrahydrofuran (THF), ethanol, dimethyl sulfoxide and so on (Meyer, 1981). The solvents evaporate during cure, which limits solids retention.…”

Improvement of white pine wood properties by impregnation with mixtures of methyl methacrylate and phthalimide monomers, subsequent in situ copolymerization

“…Composites are prepared with wood when suitable monomer is impregnated into wood, normally under vacuum (Gohar and Guyonnet, 1998) or pressure (Muraki et al , 1998), and then the monomer undergoes polymerization either by heat (Doss et al , 1991) or by radiation (Khan et al , 1991) to form a plastic like material that is very similar to cellulose constituent of wood. It has been reported earlier that wood plastic composites (WPC) formation was studied with different types of monomers such as methyl methacrylate (MMA) (Beal and Witt, 1970), vinyl chloride (Calleton et al , 1970), vinyl acetate (Kent et al , 1963), mixture of different monomers (Moustafa et al , 1977), urea‐formaldehyde resin (Kupchinov et al , 1980) and thiourea‐formaldehyde resin and orthophosphoric acid (Mahmoud et al , 2000), that leads to improvement in physical (Kent et al , 1963), chemical (Schneider and Brender, 1985), biological (Subramanian et al , 1981) and mechanical properties (Winandy et al , 1988).…”