Development of a compression test device for investigating interaction between diffusion of biodiesel and large deformation in rubber

Abstract

International audienceMotivated by environmental and economic factors, biodiesel has been introduced to partially replace the diminishing stock of petroleum-based fuel. However, the use of biodiesel such as palm biodiesel is placing additional demands on automotive components, e.g. rubber components, due to a compatibility issue in the fuel system. In engineering applications where hostile environments are involved, the long-term mechanical response of rubber components is affected by interactions existed between diffusion of liquids into the material and fluctuating multiaxial loading. Hence, it is crucial to investigate the durability of rubber components in this aggressive environment. A number of studies on static immersion tests to investigate the diffusion of liquids in stress-free rubber can be found in the literature. However, studies focusing on the coupling between diffusion and large deformation in rubber, and the resulting swelling and mechanical response under cyclic loading conditions are less common. In the present work, a compression device for the investigation of interaction between diffusion of palm biodiesel and large compressive strain in rubber is developed. The apparatus is comprised of four rectangular stainless steel plates with spacer bars in between, which are designed such that pre-compression can be introduced on the rubber specimens while they are immersed into biodiesel. This allows diffusion and large strain to take place simultaneously. Different pre-compressive strains and biodiesel blends are considered. At the end of each immersion period, the resulting swelling behavior and mechanical response of rubber specimens under cyclic loading conditions are investigated. The features of this compression device are discussed and perspectives are drawn

Modeling the Mullins effect in elastomers swollen by palm biodiesel

“…Furthermore, the only effect of swelling is to reduce the modulus in inverse proportion to the cube root of the swelling degree without changing the form of the stress-strain curves. Nevertheless, as shown in our previous work (Chai et al, 2011), deviation of Treolar's theory was observed. Hence, following Durning and Morman (1993), we postulate the following form ofŴ J s :…”

“…No standard is followed regarding the choice of the specimens and immersion durations. The detailed features of the specimen and chemical compositions of the palm biodiesel used in the present study are provided in our previous works (Chai, Andriyana, Verron, Johan, & Haseeb, 2011;Ch'ng, Andriyana, Verron, Kahbasi, & Ahmad, 2013).…”

“…In this figure, no apparent difference is observed in the nature of stress-stretch behaviors between the dry and swollen rubbers. Nevertheless, the stress-stretch responses of swollen rubbers are lower than the dry one since the presence of solvent in rubbers degrades their properties (Flory, 1953;Treloar, 1975;Chai et al, 2011). Moreover, it is observed that the stretch at fracture of swollen rubbers is lower than the one of dry rubber.…”

Degradation of aviation sealing materials in rapeseed biodiesel

“…Chai et al 4 designed a compression device to evaluate the durability of industrial rubber components exposed to an aggressive environment, for example, oil in a biofuel system during their service. The apparatus was made up of four rectangular stainless steel plates with spacer bars in between, and thus, precompression was introduced for the rubber specimens while they were immersed into diesel.…”

Interaction between diffusion of palm biodiesel and large strain in rubber: Effect on stress-softening during cyclic loading

“…Nevertheless, this level of strain is retained to represent initially stress-free condition while ensuring that the diffusion occurs only along radial direction. The details about the compression device is given in Chai et al (2011).…”