Rubber is an essential component of many everyday and specialized products used in a variety of ways. To produce rubber compounds with the physical properties necessary for good product performance, vulcanization systems may contain curatives that have negative environmental and/or biological impact. Fortunately, a significant number of curatives exist that will reduce the negative impact on health and environmental safety.
This paper will present an overview of curatives that are more eco-friendly but still appropriate and effective for various compound applications. Specifically, the area of reducing or eliminating carcinogenic nitrosamine-generating curatives will be explored.
A novel approach to this is the use of Lanxess Business Unit Rhein Chemie’s Rhenogran-brand Zeolite-70 combined with resol resins to develop fast and heat stable vulcanizates in elastomers with low unsaturation. Additionally, Rhenocure-brand DR and Vulcuren brands will be presented as safer alternatives to 1, 3-diphenyl guanidine (DPG), which produces large volumes of volatile organic compounds during decomposition. Rhenogran HPCA-50 combined with Rhenogran MTT-80 will be shown to be an effective replacement for ethylene-thiourea (ETU), which is considered to be both carcinogenic and mutagenic.
This information will assist the rubber compounder in making choices that meet the compound performance needs as well as contribute to the overall environmental and biological health of our world.