Cure Characteristics and Physico-Mechanical Properties of Natural Rubber Filled with the Seed Shells of Cherry (Chrysophyllum albidum)

Abstract

ABSTRACT:The cure characteristics and the physico-mechanical properties of natural rubber, standard Nigerian rubber, SNR10 filled with cherry seed shell (CSS) and standard carbon black CB (N330) were determined. The results showed that the scorch, cure times and the maximum torque gradually increased with increasing filler content for CSS-filled natural rubber, but in the case of CB-filled natural rubber, the scorch and the cure times decreased while the maximum torque increased with increasing filler content. The tensile strength of both CSS and CB-filled vulcanizates increased to a maximum at 40 phr filler content before declining. The moduli (M100 and M300), specific gravity (S.G), hardness and abrasion resistance increased while the elongation at break and Dunlop resilience decreased with increasing filler content for both vulcanizates. The locally sourced CSS filler, had a lower reinforcement properties compared to the CB (N330) filler, probably due to its higher moisture content and larger particle size. @JASEM Raw dry rubber is seldom, if ever used in its original state for any engineering application. Rubber manufacture involves the addition to rubber many ancillary materials called additives. This is to allow the rubber compounds to be satisfactorily processed and when vulcanized improve the application properties of the rubber articles. Additives in rubber include; vulcanizing agents, accelerators, activators/retarders, antidegradents, fillers, plasticizers and other ancillary ingredients. One of the most important additives and second largest following the base polymer in rubber compounding is the filler. Fillers improve processability, physicomechanical properties such as tensile properties, hardness, flex fatigue, tear and abrasion resistances, and may cheapen the final product. They achieve performance enhancement by forming strong chemical bonds with the rubber, that is, strong fillerelastomer interactions. The fillers used in rubber compounding can be classified into reinforcing and non-reinforcing types. A reinforcing filler is one which increases the tensile strength, hardness and abrasion resistance of the rubber article. The finer the particle size the more reinforcing a filler is. Examples of reinforcing filler include; carbon black and silica. Non-reinforcing fillers cause reduction in strength properties but may increase hardness and modulus of the rubber product. They are usually applied as diluents or extenders to generally reduce cost, examples include the whitings (CaCO 3 ) and china clay (Blow et al, 1982;Bello, 2001;Whelan et al, 1979).Carbon black is presently the most commonly used filler in the rubber industry, but it's petroleum derived and expensive commercially. Locally available materials such as limestones, eggshells, corn cobs, groundnut shells, rubber seed shells, rice husk, cocoa pod husk and Cherry (Chrysophyllum albidum) are amongst the underutilized renewable resources in our society today which can be used directly or converted by simple processes to valuable materials...

The reinforcing potentials of <i>Velvet tamarind</i> seed shell as filler in natural rubber compounds

“…The higher elongation at break and higher rebound resilience of the VT-filled SNR 10 vulacanizates implies that their products would be less rigid and would be expected to have low hysteresis and heat build-up, while the lower specific gravity suggests that the VT-filled SNR 10 products would be lighter in weight than the CB(N330)-filled SNR 10 products. These observed gradations in the physico-mechanical properties of the SNR 10 vulcanizates are consistent with the observations made earlier in previous research studies (Pranut et al, 2001, Imanah andOsabohien et al, 2006;Mohamad et al, 2008;Osabohien, 2010).…”

“…The results of the analyses shown in Table 3 revealed that VT filler has a higher moisture content compared to CB (N330) filler. High moisture content in a filler often leads to High filler dispersion in the polymer matrix resulting in a weak filler-polymer matrix adhesion hence poor mechanical strength properties of the vulcanizates (Pranut et al, 2001;Ray et al, 2001a;Wang et al, 2003;Puglia et al, 2005;Osabohien et al, 2006). The CB (N330) filler has higher weight loss on ignition at 1000 0 C than the seed shell of Velvet tamarind (VT) suggesting that CB (N330) has a higher content of carbon or carbonaceous materials than the natural plant filler, VT seed shell.…”

“…The results also showed the various metallic and non-metallic constituents of VT seed shell. The presence of these surface groups has been shown to influence the surface reactivity of a filler and hence it's reinforcing ability (Iyasele and Okeimen, 2004;Osabohien et al, 2006).…”

Cure Characteristics and Mechanical Properties of Pineapple Leaf Fibre Filled Natural Rubber

“…The past decades have witnessed increasing interest in the use of rubber products. Rubbers which are elastomers are not used as neat polymers due to lack of hardness, strength properties and wear resistance [1]. They have also being found to degrade or change their properties in the presence of air, light and at elevated temperature [2].…”

Prediction of Mechanical and Functional Features of Aged Rubber Composites Based on BR/SBR; Structure-Properties Correlation

“…There are almost no purely theoretical expressions for the prediction of properties. Therefore, recognizing the formulation of various elastomeric compounds and investigation of the relationship between physico-mechanical properties and their thermal behavior in the tire industry is important [5][6][7][8][9][10][11][12][13][14][15][16][17][18] . The TG-DTG technique is used in analysis of polymer materials 2,19 , and some reports are presented on identification of a series of rubber compounds that indicate the high precision and acceptable accuracy of this method 20 .…”