Effect of surface-functionalization of Na+-montmorillonite nanoclay using 3-aminopropyltrimethoxy silane on the mechanical properties of E-glass chopped strand mat/epoxy composites

In the present work, Na+-montmorillonite nanoclay (Na-MMT) was functionalized using 3-aminopropyltrimethoxysilane (3-APTMS) as a coupling agent. The covalent functionalization of MMT was confirmed by Fourier-transform infrared spectroscopy (FT-IR). In the specimen fabrication stage, 5 wt% of pristine MMT or silane-functionalized MMT (f-MMT) were incorporated into an epoxy system and the resultant mixture was applied on an E-glass chopped strand mat (CSM). A significant enhancement in the mechanical behavior (tensile and flexural properties) of CSM/epoxy composite was observed when enhanced with 5 wt% of f-MMT. The addition of 5 wt% of f-MMT enhanced the tensile strength, flexural strength, tensile modulus, and flexural modulus by 18%, 38%, 18%, and 28%, respectively. Compared to the MMT/CSM/epoxy composite, the f-MMT/CSM/epoxy specimen demonstrated 12%, 18%, 11%, and 16% increase, respectively, in the tensile strength, flexural strength, tensile modulus, and flexural modulus. The observed behavior is related to the enhanced interfacial interaction between f-MMT and the epoxy matrix due to the chemical functionalization of MMT. 

Keywords:

Na+-montmorillonite nanoclay , Surface functionalization , Epoxy-based composite , mechanical properties , Interfacial bonding