Determination of the crack energy threshold for crack initiation in rubber under ozone exposure

Kód výsledku v IS VaVaI

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Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Determination of the crack energy threshold for crack initiation in rubber under ozone exposure

Popis výsledku v původním jazyce

Ozone (03), an allotrope of ordinary oxygen (02), is only present in the atmosphere in very low concentrations, but could have a detrimental effect on the durability of rubber. The reason for this is a reaction between double bonds and ozone known as ozonolysis, which occurs when a gas molecule reacts with a double bond. The immediate result is the formation of an ozonide, which then rapidly decomposes and breaks the double bond. This is a critical step in which the chains are broken, leading to a rapid drop in molecular weight, complete loss of strength and cracking. Further attack then takes place on the newly exposed crack surface, and when the rubber is stretched, the crack continues to grow. Ozone cracking occurs in the various rubber products only when tension is applied, but an important point is that the critical elongation for the formation of the crack under ozone attack is very low. How large this value is, or how large the threshold energy is at which a crack occurs in rubber under the influence of ozone, is a critical point in the knowledge of the effect of ozone on rubber, which could not yet be determined with the current experimental possibilities. ln this study, a new method is presented to determine for the first time the value of the tearing energy threshold for cracking of rubber under ozone exposure. The new method presented in this paper utilizes a combination of experimental determination of ozone-induced crack initiation and subsequent interaction with the numerical calculation of the energy release rate at the crack tips. Furthermore, a novel and unique test equipment for the analysis of crack initiation and the characterization of the crack energy threshold of rubber under ozone exposure is presented.Finally, it is discussed that this new testing equipment and methodology allow the determination of the tearing energy threshold for cracking of rubber under ozone and represents an effective and unique tool for e.g. the future efficient development of environmentally friendly antiozonants replacing the widely-used antiozonant, N-(1,3-dimethylbutyl)-N&apos;-phenyl-p-phenylenediamine (6PPD).

Název v anglickém jazyce

Determination of the crack energy threshold for crack initiation in rubber under ozone exposure

Popis výsledku anglicky

Ozone (03), an allotrope of ordinary oxygen (02), is only present in the atmosphere in very low concentrations, but could have a detrimental effect on the durability of rubber. The reason for this is a reaction between double bonds and ozone known as ozonolysis, which occurs when a gas molecule reacts with a double bond. The immediate result is the formation of an ozonide, which then rapidly decomposes and breaks the double bond. This is a critical step in which the chains are broken, leading to a rapid drop in molecular weight, complete loss of strength and cracking. Further attack then takes place on the newly exposed crack surface, and when the rubber is stretched, the crack continues to grow. Ozone cracking occurs in the various rubber products only when tension is applied, but an important point is that the critical elongation for the formation of the crack under ozone attack is very low. How large this value is, or how large the threshold energy is at which a crack occurs in rubber under the influence of ozone, is a critical point in the knowledge of the effect of ozone on rubber, which could not yet be determined with the current experimental possibilities. ln this study, a new method is presented to determine for the first time the value of the tearing energy threshold for cracking of rubber under ozone exposure. The new method presented in this paper utilizes a combination of experimental determination of ozone-induced crack initiation and subsequent interaction with the numerical calculation of the energy release rate at the crack tips. Furthermore, a novel and unique test equipment for the analysis of crack initiation and the characterization of the crack energy threshold of rubber under ozone exposure is presented.Finally, it is discussed that this new testing equipment and methodology allow the determination of the tearing energy threshold for cracking of rubber under ozone and represents an effective and unique tool for e.g. the future efficient development of environmentally friendly antiozonants replacing the widely-used antiozonant, N-(1,3-dimethylbutyl)-N&apos;-phenyl-p-phenylenediamine (6PPD).

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

20501 - Materials engineering

Projekt

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Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů