Interelastomer reactions in unconventional elastomer
Polimery 2007, No 7/8, 511
On the basis of literature review the problem of formation of interelastomer networks in the elastomer blends has been presented. The own results of curing of new unconventional elastomer blends composed of carboxylated acrylonitrile-butadiene rubber (XNBR) and chlorosulfonated polyethylene (CSM) were discussed. On the basis of vulcametric measurements, equilibrium swelling and IR spectra analyses we found the formation of networks in CSM/XNBR blends containing up to 40 wt. % of CSM. These networks contain interelastomer crosslinks of ionic structure XNBRR-CO-O(-)(+)Me(+)(-)O-SO2-RCSM (Table 1, Fig. 1) while CSM itself did not undergo curing in the conditions applied. The factors deciding about the reaction progress and the properties of the blend cured are CSM/XNBR weight ratio and type and amount of metal compound used as a curing agent (Table 2). The best results were found for the blends cured with MgO, Mg(OH)2, ZnO or basic zinc carbonate introduced into the blend in amounts >300 mmol/100g, at temp. >413K (>140°C) (Table 3). The type of CSM used (containing bonded chlorine in the range 29-43 wt. %) did not affect significantly the curing degrees of the blends discussed (Table 4).
Key words: elastomer blends, carboxylated acrylonitrile-butadiene rubber, chlorosulfonated polyethylene, curing, metal(II) oxides, interelastomer networks, properties of cured products
W. M. Rzymski, M. Kmiotek
Interelastomer reactions in unconventional elastomer blends