Effect of Water-Soluble Salt Additives on Water Absorption Rubber Based on Ethylene Propylene Diene Rubber

Abstract

The water absorption capacity of rubbers based on ethylene propylene diene rubber SKEPT-40 with the addition of increased amount of water-swelling reagent (90,0 phr of Na-CMC per 100,0 phr of rubber) and water-soluble salt additives (sodium salts Na2CO3, NaHCO3, NaCl) when exposed to distilled water, 3 % and 10 % of aqueous solutions of NaCl during 20 days. The resistance of rubbers to thermal aging has been studied. It was noted that the volume change during swelling of samples containing the water-swelling reagent Na-CMC and salt additives in distilled water increased compared to the sample without salt additives. It has been established that due to the use of water-soluble salt additives under other identical conditions, such as the basic formulation of water-swelling rubbers, environment etc., it is possible to increase water absorption and water swelling. An increased change in the volume of rubber samples was found due to the use of combination of salt additives namely 4,0 phr of Na2CO3 and 3,0 phr of NaCl per 100 phr of SKEPT-40. The results of this work can be used in the development of sealing elements of water-swelling and oil-swelling packers.