Multifunctional action of in situ formed Zn-salt of monoallylmaleamic acid

Monoallylmaleamic acid (CH₂=CH-CH”2-NH-CO-CH=CH-CO-OH; MAMA) when used in combination with zinc basic carbonate (ZBC) shows multifunctional action during processing and peroxide curing of hydrogenated nitrile rubber (HNBR). It follows from the lower viscosity, higher crosslinking degree and higher tensile strength of samples prepared from HNBR, MAMA, ZBC and peroxide, compared with the HNBR cured with the peroxide only. This kind of activity of the such system is connected with the in situ formation of very small particles of Zn-MAMA salt dispersed in the rubber matrix and in part chemically bound to the rubber.