Mechano-chemically activated fly-ash and sisal fiber reinforced PP hybrid composite with enhanced mechanical properties

This study explores the hybridizing effect of mechano-chemical activated fly-ash (FA) in polypropylene (PP) composites reinforced with sisal fibers. Activation and resistance against agglomeration of FA has been achieved by modifying it with 2, 4, and 6 wt.% of the cetyltrimethylammonium bromide (C-tab). FA activation with C-tab and particle size reduction to nano-level (< 1 mu m) have been appropriately achieved with a planetary ball milling and the same has been confirmed from the dynamic light scattering technique. The hybrid composite containing 25 wt.% of sisal fiber and 5 wt.% of (6 wt.% C-tab) treated FA shows much improved tensile (40.12 MPa), flexural (53.27 MPa), and impact strengths (0.75 kJ/m(2)) than that of virgin PP and its 30 wt.% sisal fiber composites. This increase in tensile and flexural strength was 30.54% and 48% higher than neat PP. Maximum notched impact strength of 0.80 kJ/m(2) have been reported by hybrid composite containing FA treated with 2 wt.% of the C-tab. Micromechanical modelling using a combination of rule of mixture and inverse rule of mixture separately with Halpin-Tsai predicted a value close to the experimental Young's modulus. DSC studies showed an increment in the composite's crystallinity upon fiber addition. Morphological analysis of the hybrid composite revealed good wettability of reinforcing fiber and FA within the matrix, whereas TGA showed an improved thermal stability of the composites. [GRAPHICS] .

Automated summary

The study demonstrated the successful hybridization of sisal fiber-reinforced polypropylene composites using mechano-chemical activated fly-ash with the addition of cetyltrimethylammonium bromide. The hybrid composite showed significantly improved mechanical properties compared to virgin PP and sisal fiber composites, with enhanced tensile, flexural, and impact strengths. Morphological and thermal analyses confirmed the good wettability of reinforcing fiber and fly-ash within the matrix, as well as improved thermal stability of the composites.