Search

The present work reports on the preparation and investigation of the properties of composites based on acrylonitrile butadiene rubber (NBR) aimed for production of sealants in water supply networks carrying hot and cold potable water. The studies involve 12 NBR-based composites. A conventional, semi-efficient and efficient sulphur-vulcanization system is used for four of the composites. A vulcanizing agent, dicumyl peroxide, was used in the other eight composites. The results obtained show that the type of the vulcanization system used has a significant impact both on the vulcanization characteristics of the investigated rubber compounds and on the mechanical properties of their vulcanizates. The comparison of the results obtained and the requirements of standard EN 681-1:1996 referring to the mechanical properties of the elastomer composites used for production of sealants for pipes carrying hot and cold potable water reveal that composition P-10 is the most suitable for the purpose. The microbiological characteristics of the water in contact with the composites indicate that no bacterial growth occurs in the samples tested as a result of this contact. The latter does not lead to a change of the organoleptic parameters as well. Higher values of heavy metals, nitrates or nitrites are not observed. [ABSTRACT FROM AUTHOR]