Interaction Between Wood and Synthetic Polymers

Abstract

The properties of wood composites consisting of low density polyethylene (LDPE) and wood flour (WF) were studied. In an attempt to improve the interfacial adhesion between hydrophobic LDPE matrix and the hydrophilic WF filler, a styrene-butadiene-styrene (SBS) copolymer was added as a compatibilizer. The interaction between LDPE and wood was investigated for PE/WF-and PE/WF/SBScomposites. The experimental measurements were conducted by conventional mechanical testing and Scanning Electron Microscopy (SEM). The interaction between polystyrene and wood in PS/WF composites was also studied by SEM and by Dynamic Mechanical Thermal Analysis (DMTA). PE/WF/SBS composites showed higher maximum tensile stress and strain at failure than the composites without SBS. SEM fractography confirmed better adhesion between the PE matrix and wood particles when SBS was present. DMTA measurements confirmed molecular interaction between PS and wood, the glass transition (Tg) peak of PS moved towards the Tg peak of cellulose.

The nature and location of SEBS-MA compatibilizer in polyethylene-wood flour composites

“…The SBS was found to locate at the interface between the wood and LDPE matrix having a cylindrical morphology and an interface thickness of approximately 0.1 mm. 13 It is expected that the morphology of composite systems would be similar regardless of the material used (SBS or SEBS-MA).…”

“…After that, the samples were stained with OsO 4 WF-SBS system. 13 The SBS compatibilizer was stained with OsO 4 to distinguish it from the LDPE vapor for about 2 h in order to give good contrast for the unsaturated part of the EB-MA blocks in matrix. As a result of the study, the SBS was found to locate at the interface between the PE the copolymers.…”

“…If the styrene concell wall was not stained in the previous study when SBS was used. 13 One more possibility is that tent in the SEBS-MA is higher than 28 wt % then the structure of copolymer can be one of cylindrithe SEBS-MA is taken from the interphase to the cell wall with the knife during sectioning. The cal or spherical EB domains in the PS matrix.…”

“…Several investigations of the interfacial region between reinforcement and polymer matrix have been made by using TEM. 13,15,21,22 Previous work with PE-WF composites has shown that the SBS copolymer compatibilizer is located at the interfacial region between WF surfaces and the PE matrix and also distributed in Figure 1 Schematic description of the grafting of the PE matrix. 13 SBS was also found to be located SEBS with MA.…”

“…15 In a polypropylene-cellulose fiber (PP-CF) composite system, a maleand was found to be located at the interfacial region between the LDPE matrix and the wood parated polypropylene (MAPP) used as compatibilizer was found to be located at the interface beticles. 13 Previous work [10][11][12] has shown that maleic-anhydride-grafted styrene-ethylene-butyltween the CF and the PP matrix. The reason for the MAPP being located at the interface, forming ene-styrene (SEBS-MA) triblock copolymers have a stronger compatibilizing effect between an interphase between the PP and CF, is thought to be the difference in polarity between the wood wood flour and polyethylene and polypropylene.…”