This study examined the effects rheological properties of different composition kaolin and kaolin geo-filler in polypropylene composites. Polypropylene composites with varying composition of kaolin geo-filler 0 wt%, 2 wt%, 4 wt%, 6 wt%, 8 wt%, and 10 wt% was prepared and compared with polypropylene composite with raw kaolin. Kaolin is an aluminosilicate based mineral filler was used to prepare geopolymer paste by combining with alkaline activator solution. The polypropylene composite was compounded using a twin-screw extruder and the melt flow index was determined by a constant weight pressure of 2.16 kg at 230°C in 10 min. Knowing the melt flow index is necessary to predict and control the process, the study has demonstrated that the composition of kaolin filler and kaolin geo-filler affects the melt flow, melt density and surface morphology at varies composition. Composites with kaolin geo-filler have demonstrated high melt flow index process and having better distribution and flow.

Geopolymer is formed from the alkali activation of materials rich in Si and Al content with the addition of a silicate solution to enhance the properties of the materials. This paper presents research on the mechanical properties of fly ash-based geopolymer filler in epoxy resin by varying different solid to liquid ratios using sodium hydroxide and sodium silicate as the alkaline activator. However, the common problem observed from the solid to liquid ratio is the influence of curing time and compressive strength of geopolymer to have the best mechanical property. The mix design for geopolymers of solid to liquid ratio is essential in developing the geopolymer’s mechanical strength. A series of epoxy filled with fly ash-based geopolymer materials with different solid to liquid ratio, which is prepared from 0.5 to 2.5 solid to liquid ratio of alkaline activator. The tensile strength and flexural strength of the epoxy filled with fly ash-based geopolymer materials is determined using Universal Testing Machine under tensile and flexural mode. It was found that the optimum solid to liquid ratio is 2.0, with the optimum tensile and flexural strength value. However, both the tensile and flexural properties of epoxy filled with fly ash-based geopolymer suddenly decrease at a 2.5 solid to liquid ratio. The strength is increasing with the increasing solid to liquid ratio sample of geopolymer filler content.

This research was conducted to examine the corrosion behaviour of mild steel bar embedded in geopolymer paste based fly ash Class F during curing and non-curing process. The geopolymer paste was fabricated by blending in the fly ash with alkaline activators (NaOH solution with molarity of 12 M, 2.5 ratio of solution Na2SiO3/NaOH). The paste was produced in 50 mm × 50 mm × 50 mm mould where the mild steel bar of 100 mm (length) × 12 mm (diameter) was embedded at the center of geopolymer paste. This is to comprehend the corrosion behaviour of mild steel embedded in geopolymer paste with and without curing process. Process of curing is carried out for 24 hours at a temperature of 60°C in oven. While on the contrary, the non-curing process will only be leave at room temperature. Both samples were tested after 28 days of curing to determine the corrosion behaviour, phase analysis and morphology analysis. In accordance with the morphology analysis, it shows that the fly ash was totally reacted with alkaline solutions in curing geopolymer paste sample while the non-curing geopolymer paste has shown the unreacted fly ash with high number of pores. The phase analysis of mild steel embedded in this geopolymer paste during curing and without curing process has proven that the presence of new crystallographic peak which also known as passive layer occurred. The potential values result by OCP testing shows the curing sample has highest potential values as compared to the non-curing sample ones.