Mechanical properties, water‐swelling behavior, and morphology of water‐swellable rubber prepared using crosslinked sodium polyacrylate

Abstract

A novel water-swellable rubber (WSR) has been prepared by blending chlorobutadiene rubber (CR), reactive clay and other additives with crosslinked sodium polyacrylate (CSP), which was modified by interpenetrating polymer networks (IPNs) technology with crosslinked P(AA-co-BA). The structure of WSR was characterized by scanning electron microscopy (SEM). The mechanical properties, water-swelling ratio by mass, and the percentage loss of CSP in the WSR were investigated. The results showed that the modified CSP grains can be dispersed well in the CR, and that it resulted in increase of mechanical properties and water-swelling ratio and in decrease of percentage loss of CSP, compared with the unmodified one. When the percentage content of crosslinked P(AA-co-BA) used to modify CSP reached 30%, the tensile strength, elongation at break, and water-swelling ratio of WSR exhibited maximum value, and percentage loss of CSP exhibited minimum value. When the content of CSP in WSR was 30 phr, the tensile strength, elongation at break, and water-swelling ratio and percentage loss of CSP of the WSR containing CSP modified were 7.7 MPa, 1530, 438, and 2.5%, respectively.

Water swellable rubber composites: An update review from preparation to properties

“…3 For example, internal mixing, Banbury, and two-roll milling are batch mixers. Mixing with an extruder in continuous mixing is a common method for dispersing SAP (powder or resin) into the rubber.…”

“…[3][4][5][6][7][8][9] They are usually mixed with various water-absorbent materials known as superabsorbent polymers (SAPs). SAP is a kind of hydrophilic polymer (cross-linked hydrogel) having water-absorbing capacity from 100 up to 2000 g/g, in which the absorbed water is scarcely removable even under pressure, because the water molecules are held tightly in the network by hydrogen bonding.…”

“…3 This new technology has opened a wide range of variations in the preparation of WSR which can customize the properties to the specific needs of many different applications. Yoo et al prepared PDMS interpenetrating networks of two different molecular weight PDMS, and the swelling, mechanical property, and toughness results proved that the load was effectively transferred between the networks.…”

The role of dicumyl peroxide in the preparation of chloroprene rubber/starch/sodium acrylate water-swellable composites

“…We recently prepared several rubber/starch composites by co-coagulating starch paste and rubber latex which exhibited better mechanical properties than the corresponding composites prepared by direct blending (CN, 2003;Wu, Ji, Wang, & Zhang, 2004;. In most WSRs, the water-swelling capacity is mainly achieved by incorporating water-absorbing components (Liu et al, 2006;Wu, Lin, Wei, & Lin, 2005;Wu, Wei, Lin, & Lin, 2003;Zhang, Li, & Wang, 2006), e.g., sodium polyacrylate, starch grafts, and cellulose grafts. Among these additives, sodium polyacrylate shows some advantages including high water swelling ratio and rate, stable structure, and low price.…”

“…But it is not easy to prepare WSRs simultaneously showing good mechanical properties and high water-swelling capacity. Natural rubber, ethylene propylene diene terpolymer (EPDM) rubber, chloroprene rubber (CR) and other rubbers used as the matrix provide the elasticity of WSRs, and reinforcing fillers such as carbon black, silica, attapulgite and starch are used to improve the mechanical properties of rubbers (Liu, Ding, Zhou, & Chen, 2006;Park & Kim, 2001;Song, Qi, & Wu, 2010;Sun et al, 2002;Tang et al, 2006;Wang, Li, & Chen, 1999). We recently prepared several rubber/starch composites by co-coagulating starch paste and rubber latex which exhibited better mechanical properties than the corresponding composites prepared by direct blending (CN, 2003;Wu, Ji, Wang, & Zhang, 2004;.…”