Improvement of mechanical and physical performance of poly (lactic acid) biocomposites by application of surface silanization for huntite–hydromagnesite mineral.

Silanization process was applied to huntite–hydromagnesite (HH) mineral in for improve its adhesion to poly (lactic acid) (PLA) matrix. Surfaces of HH samples were examined by infrared spectroscopy and energy-dispersive X-ray spectroscopy analysis. HH was compounded with PLA using melt-blending technique. Modified HH incorporations led to nearly 19% and 20% increase in tensile strength and modulus of PLA, respectively. The maximum improvement for tensile strength value is obtained for 15 wt% of modified HH containing composite sample. On the other hand, percentage strain of PLA decreases nearly 22% with the addition of HH. Silane-modified HH-containing composites yield higher impact energy compared to untreated HH. Impact performance of composites increases nearly 18% with the increase in loading ratio of HH. Silane-modified HH displays higher storage modulus than HH, and glass transition temperature of PLA shifts to higher levels with the inclusion of HH. HH-filled composites exhibit no significant difference with melt flow rate value of PLA. Water resistance of silane-treated HH-containing composites are found to be higher than untreated HH attribitued to hydrophobicity of silicon-rich surface. Accordingly, composites that include modified HH are suitable for outdoor applications. Morphological investigations confirm that dispersion homogeneity and strong adhesion are achieved due to the improvement of surface interactions between HH and PLA phases after silane treatment process. [ABSTRACT FROM AUTHOR]