Published : 2022-09-18

Properties of carboxylated acrylonitrile/butadiene rubber containing "in situ" synthesized silica fillers

Abstract

From silica precursors we synthesized silica fillers in sol-gel reaction in the carboxylated acrylonitrile/butadiene rubber (XNBR). N-2-aminoethyl-3-aminopropyl-trimethoxysilane (DAMS) and tetraethoxysilane (TEOS) were used as fillers' precursors. It has been found that DAMS is a substance crosslinking XNBR. The network points are silsesquioxanes' domains containing amide as well as ionic bonds. Some part of points (similar to30%) decompose under ethylenediamine treatment. The bigger DAMS content the bigger crosslinking density of elastomer as ell as the stress at suitable elongation and tensile strength Tables 2 and 4). The dynamic properties measurements show that rganosilica compounds do not influence glass transitiontemperature of elastomer (Table 6) but in the range of 30-40degreesC the second maximum appears which is a transition connected to ionic aggregates activity. Addition of a mixture of DAMS + TEOS to the elastomer causes the increase of crosslinking of silsesquioxanes' domains and the filler shows tendency to creation of its own structure (Fig. 2). Si-29 NMR results show that mostly trifunctional structures Q(3) are obtained for equal ratio of silanes (1:1) but tetrafunctional structures Q(4) are also present (Table 1). The increasing of tetrafunctional structure Q(4) content, that is a synthesis of a filler with DAMS + TEOS mixture, leads to the increase of stress at suitable elongation, and tensile strength (Table 5).


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Zaborski, M., & Pietrasik, J. (2022). Properties of carboxylated acrylonitrile/butadiene rubber containing "in situ" synthesized silica fillers. Polimery, 47(9), 643–649. Retrieved from https://polimery.ichp.vot.pl/index.php/p/article/view/2012