Effects of Thermal Aging on The Mechanical Properties of Natural Rubber

Abstract

The focus of this research was to investigate the effect of thermal degradation upon the mechanical properties of a natural rubber compound. We examined both the quasi-static and dynamic mechanical properties of a natural rubber vulcanizate which had been subjected to isothermal, anaerobic aging. The thermal aging was conducted between the temperatures of 80 °C and 120 °C for times ranging from 3 to 24 days. The effect of thermal degradation was measured using the changes in the crosslink distribution of the vulcanizates as functions of time at temperature. A master curve relationship between the crosslink distribution of the vulcanizates due to thermal degradation and the static and dynamic mechanical properties has been developed. It was found that the both the quasi-static and dynamic mechanical properties correlated with the percentage of poly and monosulfidic crosslinks, where in general higher levels of polysulfidic crosslink gave rise to the highest mechanical properties.

Influences of thermal aging on properties and pyrolysis products of tire tread compound

“…The rubber chains were highly vulcanized, resulting in the decrease in the number of free chains, and the polysulfidic bonds could be broken into di-and mono-sulfidic ones as so-called maturation of sulfur crosslinks [11] and also confirmed by the work by South [9], indicating that the percentage of polysulfidic crosslinks in natural rubber chains decreased as the percentage of mono-sulfidic crosslinks increased with thermal aging. Furthermore, the oxygen linkages could be partially occurred, leading to higher crosslink density and greater hardness.…”

“…Similarly, Ahlblad et al [26] also found that thermal oxidation of hydroxyl-terminated polybutadiene rubber increased crosslink density. It is likely that thermal decomposition of polysulfidic bonds may proceed faster than the oxidation of the rubber chains [9]. The model illustration is shown in Fig.…”

“…Many researchers have studied the effect of aging on various aspects, such as mechanical properties [9], rheological properties [10], and tensile strength [11] of tire or rubbers as well as their degradation mechanism [12]. Rattanasorn et al [13] investigated mechanical properties and heat aging resistance of rubber blends, which were composed of NR and various contents of tire tread reclaimed rubber (RR).…”

Investigation of thermo-oxidative ageing effects on the fatigue design of automotive anti-vibration parts

“…Ageing could indeed induce severe modifications of the mechanical properties both in terms of constitutive response [11], failure properties under monotonic tension [12], crack propagation [13] and duration life [14]. Nevertheless, relating the degradation mechanisms to the evolution of the mechanical properties is not an easy task because there are so many mechanisms at stake.…”

Influence of rubber and fabric cord on deformation of a fabric cord-inserted rubber composite by thermal aging

“…One of the principal reasons regarding permanent deformation of a rubber vulcanizate is change in crosslink density [3]. Thermal aging causes the crosslink density of a rubber vulcanizate to change [1,[4][5][6][7][8][9].…”