PERFORMANCE OF TREATED HYBRID FIBER REINFORCED-THERMOPLASTIC COMPOSITES UNDER EXTREME CONDITIONS .4. USE OF GLASS-FIBER AND SAWDUST AS HYBRID FIBER

The mechanical properties and dimensional stability of hardwood aspen in the form of sawdust and surface-treated glass fiber-polystyrene composites were evaluated under various extreme conditions, e.g., variation in the testing temperature (from +25-degrees to -20-degrees-C), exposure to boiling water and heat in an oven at +105-degrees-C. The compatibility of wood fiber with glass fiber and with polystyrene improved by precoating the wood fiber with a coupling agent, e.g., 8% isocyanate, 4% silane and polymer. The mechanical properties of the composites, in particular, treated sawdust/glass fiber-filled composites, increased under extreme conditions in comparison with those filled with nontreated sawdust/glass fiber. Under the same conditions, dimensional stability also supports this observation.