Mechanical and morphological properties of white rice husk ash filled polypropylene/ethylene‐propylene‐diene terpolymer thermoplastic elastomer composites

Abstract

ABSTRACT:The performance of white rice husk ash (WRHA) as filler for polypropylene (PP)/ethylene-propylene-diene terpolymer (EPDM) thermoplastic elastomer (TPE) composites was investigated. The composites with different filler loadings were prepared in a Brabender plasticorder internal mixer. Both unvulcanized and dynamically vulcanized composites were prepared. Mixing and vulcanization processes of the composites were monitored through the typical Brabender torque-time curves. The mechanical properties and morphology of the composites were also studied. The Brabender torque curves revealed that the dynamic vulcanization process employed was successful and incorporation of filler has no adverse effect on the processibility of the composites. Incorporation of WRHA improves the tensile modulus and flexural modulus and lowers tensile strength, elongation at break, tear strength, and toughness of both types of composites. Dynamic vulcanization significantly enhances the mechanical and TPE properties of the composites. Dynamic mechanical analysis (DMA) study revealed the existence of two phases in both types of composites. It further shows that neither dynamic vulcanization nor filler agglomeration has played a prominent role in the compatibility of the composites. Thermogravimetric investigation shows that dynamic vulcanization or WRHA loading has not adversely affected the thermal stability of the composites. The scanning electron micrographs provide evidence for the tendency to form filler agglomerates with increasing filler loading, better filler dispersion of dynamically vulcanized composites over unvulcanized composites, and effective vulcanization of elastomer phase of the composites in the presence of filler.

Recycled Polypropylene/Peanut Shell Powder Composites: Pre-Treatment of Lignin Using Alkaline Peroxide

“…The PSP addition increased the viscosity and the stabilization torque (Ismail and Salmah 2001). Filler particle agglomeration occurs at higher filler loadings and leads to a higher equilibrium torque (Siriwardena et al 2002). When comparing both composites, the treated composites presented a higher stabilization torque than the untreated composites.…”

“…Hence, premature failure of the composites occurred at higher filler content, indicating lower tensile strength. High filler loading can result in agglomeration, which is detrimental to the mechanical properties (Gauthier et al 1998, Siriwardena et al 2002.…”

Utilization of waste expanded polystyrene: Blends with silica-filled natural rubber

“…As the filler agglomeration is less for compatibilized blends, the filler particles can be properly wetted by macromolecules and hence adhesion between the filler and matrix improves. Thus, the energy required to propagate a crack increases, resulting in higher tear strength [40]. The values show a decreasing tendency as the MA concentration further goes up.…”

Formulation and Performance Evaluation of Wood Adhesives Produced with Rice Husk Ash as New Filler

“…Fillers are generally added in adhesive formulations to provide some of these simultaneous benefits [3]: increase thermal and electrical conductivity, increase thermal stability, reduce coefficient of thermal expansion, reduce shrinkage and stress during cure, improve bond strength, improve flow properties, extend pot life, reduce cost [3] [5]. Substances often used as fillers include: silver flake, aluminium nitride, composite clay, zinc oxide, carbon black, hydrated alumina, calcium carbonate, fused silica, silicates and boron nitride.…”

“…RHA has been reported as excellent filler in natural rubber and epoxidized natural rubber [16 -18]. Incorporation of RHA in polypropylene composites has been reported to improve the tensile modulus and flexural modulus of polypropylene/ethylene-propylene-diene terpolymer [5], increase the degree of crystallinity of polypropylene by small margin [19], improve the adhesion and phase continuity in the polypropylene composites [20] and enhances thermal stability of epoxy foams [21]. RHA has been reported as adsorbent in water treatment and vegetable oil treatment [22], as an additive to high performance building blocks, concrete and mortar [23], as extender in textured paint [15] and red oxide primer [24] and as a good flatting extender in cellulose matt paint [25].…”