Swelling behaviour of isora/natural rubber composites in oils used in automobiles

Abstract

Natural rubber/isora fibre composites were cured at various temperatures. The solvent swelling characteristics of natural rubber composites containing both untreated and alkali treated fibres were investigated in aromatic and aliphatic solvents like toluene, and n-hexane. The diffusion experiments were conducted by the sorption gravimetric method. The restrictions on elastomer swelling exerted by isora fibre as well as the anisotropy of swelling of the composite have been confirmed by this study. Composite cured at 100°°C shows the lowest percentage swelling. The uptake of aromatic solvent is higher than that of aliphatic solvent for the composites cured at all temperatures. The effect of fibre loading on the swelling behaviour of the composite was also investigated in oils like petrol, diesel, lubricating oil etc. The % swelling index and swelling coefficient of the composite were found to decrease with increase in fibre loading. This is due to the increased hindrance exerted by the fibres at higher fibre loadings and also due to the good fibre-rubber interactions. Maximum uptake of solvent was observed with petrol followed by diesel and then lubricating oil. The presence of bonding agent in the composites restrict the swelling considerably due to the strong interfacial adhesion. At a fixed fibre loading, the alkali treated fibre composite showed lower percentage swelling compared to the untreated one.

Organic Solvents Transport Through Alkali-Treated Agro-waste Microfibre Incorporated with Low Density Polyethylene Composites

“…Table 6 also shows that the sorption coefficient is highest in benzene, followed by toluene, and then xylene at all temperatures. However, the above results are in contrast to the findings of some authors [18,40] who reported a decrease in sorption coefficient with an increase in filler content.…”

“…The degree of swelling, interface strength and extent of dispersion of fillers in a polymer matrix composites can be deduced from the swelling parameter value [18,29]. The characteristic swelling behaviour of polymer composites can be obtained from the swelling properties like swelling index, swelling coefficient etc.…”

“…The change in the Gibbs free energy of sorption (∆G ) for the three organic solvents in microfibre filled low density polyethylene composites are calculated using the expression; ∆G = ∆H − T∆S (18) where T is the absolute temperature. The values of ∆H and ∆S for the solvents calculated by equation (16) are used in equation (18), to get the values of ∆G which are presented also in Tables 10 -12.…”

“…They found that the mechanism of diffusion in the neat rubber sample is Fickian in nature, while the filled composites showed nonFickian behaviour. Sorption behaviour of isora/natural rubber composites has been investigated by Lovely et al [18]. Their findings revealed that the uptake of aromatic solvents is higher than aliphatic solvents for the composites.…”

Mechanical and hydrodynamic swelling characteristics of bovine tanned leather post-treated by acrylic and glutaraldehyde tanning agents

“…Mol % uptake of water during swelling for the leather samples can be measured by the following equation (Mathew et al, 2006): (3) where, Q t is the mol % uptake of water. W f and W o are weights of the leather samples before and after the swelling and M s is the molar mass of water.…”