Study of the effect of thermo-oxidative aging on the behaviour of elastomers

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Study of the effect of thermo-oxidative aging on the behaviour of elastomers. Elastomers are among the most commonly used materials in the manufacture of protective gloves. However, like most polymers, they are sensitive to high temperature aging.

Research involving neoprene has shown that thermo-oxidative aging causes an increase in tensile strength and in hardness, as well as a reduction in elongation at break. These variations were successfully described by an Arrhenius kinetics model. A reduction in the tearing energy, which is controlled by a viscoelastic process, is measured after aging, while the cutting energy remains unaffected. A theoretical model was developed for tensile hysteresis, allowing the prediction of behaviour based on the aging conditions and the applied rate of deformation. Finally, it was shown that the oxidation induction time can be used to predict the ultimate performance (tear and elongation at break) of elastomers at the lowest temperatures.

Furthermore, preliminary studies carried out with butyl rubber also show that thermo-oxidative aging significantly increases its sensitivity to solvents both in terms of the degree of swelling and of mechanical resistance. This phenomenon could become very problematic since gloves are stored in warehouses with no air conditioning, particularly so because changes that occur are not visible to the naked eye. All these projects have been covered in three international scientific journals, in one conference proceedings article and in a conference presentation. The results on neoprene were also included in Dr. T. Ha-Anh's thesis, entitled « Influence du vieillissement thermo-oxydatif sur les comportements mécaniques du polychloprorène » (Influence of thermo-oxidative aging on the mechanical behaviour of polychloroprene), and submitted in December 2007.