Studies on Fabrication and Characterization of Nanoclay Reinforced Nylon-6 composites: Enhancement of Heat distortion Temperature

Abstract

Organically modified nanoclay (cation exchange capacity of 135 to 145 meq/100 g) was used as nanophase reinforcement for fabrication of nylon-6 nanocomposites. The thickness of clay platelets varied form 1.2 nm to 1.3 nm with 3.485 nm as d-spacing. Nylon 6/nanoclay composites were fabricated with loading of 2.5, 5.0 and 10 wt. % nanoclay via direct melt compounding technique using conventional twinscrew extruder. Processing temperature profile from hopper to header was 230-240-245-260 °C and screw speed was maintained at 180 rpm. The nylon 6/clay nanocomposites were characterized for thermal and mechanical properties. The structural properties were characterized by Differential Scanning Calorimeter (DSC) and X-ray diffraction analysis. The tensile fracture morphology was analyzed by using Scanning Electron Microscope (SEM). DSC nonisothermal curves show an increase in the crystallization temperature with increasing degree of crystallinity. The crystallization rate of the nanoclay reinforced nylon 6 composites was found to be significantly faster than that for the pristine nylon 6 and suggests that the layered silicates act as nucleating centers. XRD result shows that addition of nanoclay by this technique favors the formation of γ-crystalline phase in nylon 6/nanoclay composites. Due to this, there is substantial enhancement in the tensile strength and Izod impact strength. A variation from 700 to 971 Kg/cm² for tensile strength and from 3.0 to 3.4 Kg.cm/cm of notch for Izod impact strength. The detailed results are presented.