Effect of the carbon black type and load on the fatigue properties and thermal expansion of the rubber

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28610%2F25%3A63592198" target="_blank" >RIV/70883521:28610/25:63592198 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Effect of the carbon black type and load on the fatigue properties and thermal expansion of the rubber

Original language description

This study investigates how different types of carbon black (CB) and mechanical loading conditions influence the thermal expansion and fatigue behavior of styrene-butadiene rubber (SBR)-based compounds. Special attention is given to how static compressive loading impacts thermal expansion, with the aim of identifying early indicators of structural damage within the rubber matrix. Five grades of carbon black Nl 15, N220, N330, N550, and N772 were incorporated into the rubber compounds and compared with an unfilled SBR reference. Fatigue properties were characterized using an Intrinsic Strength Analyzer (ISA), which provided two key parameters: the intrinsic strength (To), representing the fatigue threshold, and the ultimate strength (Te), corresponding to the critical failure point [1; 2; 3]. These parameters are essential for predicting the service life and crack resistance of rubber materials. Thermal expansion was evaluated by measuring the coefficient of thermal expansion (CTE) in two states: (1) unloaded specimens and (2) specimens subjected to 50% static compressive deformation for 24 hours.The results reveal a clear load dependency of thermal expansion. In all cases, loaded samples showed higher CTE than their unloaded counterparts. Notably, the unfilled SBR displayed the highest CTE overall. For unloaded samples, CTE increased with carbon black particle size up to N550, then slightly decreased with N772. However, in loaded samples, CTE decreased consistently as CB particle size increased. Fatigue testing revealed that unfilled materials exhibited the poorest crack resistance. Among filled compounds, crack resistance decreased with increasing CB particle size up to N550, then improved with N772. Importantly, a strong inverse relationship between crack resistance and CTE was observed: materials with better fatigue performance exhibited lower thermal expansion, and vice versa.These findings highlight the significant role of both mechanical loading and CB type on the thermal and mechanical behavior of rubber. The study demonstrates that CTE is not only sensitive to material composition but also a useful indicator of structural integrity under load. This underscores the importance of considering thermal expansion in the design and evaluation of rubber components, especially for applications where mechanical stresses are unavoidable.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20501 - Materials engineering

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

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