Study On Water Swelling Rubber Based On Nitrile-butadiene Rubber

In this study, Water-swellable rubber was prepared by blending nitrile-butadienerubber/polyacrylamide/polyurethane prepolymer. The morphology and properties ofWater-swellable rubber were studied by means of tensile strength, tear strength, agingresistance, water-absorbing rate, water-swelling ratio, weight loss ratio and SEM tests.The main results are as following:1. The effect of super absorbent resin and polyurethane prepolymers’ amount onthe Water-swellable rubber’s mechanical properties and water-swelling performancewere studied. The results show that, with the increased of the amount ofpolyacrylamide, the mechanical properties were decreased significantly and thewater-absorbing rate and water-swelling ratio of the Water-swellable rubber increase.The polyacrylamide can break off from the elastomer network easily. With the increaseof prepolymer content, the water-absorbing rate and water-swelling ratio of theWater-swellable rubber increase. It has a excellent mechanical properties when theprepolymer was40phr. Effects of different blending ratios of Polyurethaneprepolymers and polyacrylamide on the WSR of mechanical properties and thewater-swellable performance were studied in this paper. The results showed that themass loss rate decreased, both absorbent expansion rate and repeated water absorptionproperties were increased when the blending ratios of Polyurethane prepolymers andPAM was30/30.2. The effect of coupling agent species on the properties of Water-swellablerubber filled with silica were investigated. The results showed that the compression setdecreased and the mechanical properties improved with the amount of coupling agentof Si69or KH550. The coupling agents make the crosslink density of water-swellablerubber increase and water-swelling ratio decrease. SEM showed that the interfacebonding between the polyacrylamide and NBR was improved by adding polyurethaneprepolymers.3. The mechanical properties were decreased by the adding PEG-4000, which hadlittle influence on compression set.The PEG-4000can significantly improve thewater-absorbing rate, but other water absorption properties were decreased.4. Effect of sulfur content on the properties of Water-swellable rubber was studied,and the results revealed that with the increase of sulfur amount, the tensile strength, tear strength and the water-absorbing rate increased, while the elongation at break,water-swelling ratio and compression set decreased.5. The effect of different curing systems on the properties of NBR vulcanizateswere studied. The results indicated that water-swellable rubber cured with peroxidecuring system showed better mechanical properties, aging resistance and waterabsorption properties, but it deformed after water swelling and can not meet therequirements of plugging material. Generally, the Water-swellable rubber had goodcomprehensive properties with traditional sulfur curing system.