Effects of silane modified minerals on mechanical, microstructural, thermal, and rheological properties of wood plastic composites

This experimental study investigates the influence of silanized micro-size silicate-based minerals on mechanical, thermal, and rheological properties of wood (maple) polymer (high-density polyethylene) composites. The silicate-based minerals used in the experiments are prepared from mine tailings through the inertization process (acid leaching). Two different types of organo-functional silanes including vinyl-trimethoxy and amino-ethyl amino-propyl trimethoxy silanes (3%) are used to modify the mineral fillers. The different amounts of mineral fillers (1-5%) are added to the composites as wood filler replacement and while the composite properties are evaluated. The obtained results implicated that the addition of 1% silane modified minerals decreases the rigidity and increases the ductility (up to 25%) of wood polymer composite. Mineral fillers modified with vinyl-silane were more effective to improve both tensile and flexural strengths and less advantageous on rheological behaviour. Amine-modified minerals had no negative influence on rheological performance even if they significantly decreased the rigidity of composites. Both surface modified minerals improved the thermal stability of wood plastic composites.