Long-Term Stability of Superabsorbent Gel for Cable Water-blocking Performance

摘要

Current cable water penetration requirements only examine the performance of water-blocking superabsorbents in a dry state, either virgin or aged. With today's robust designs, a leak may go undetected allowing the interior of a cable to be exposed to a water head for years. In this scenario, the long-term stability of the hydrated superabsorbent gel is critical to prevent water migration down a cable to sensitive closure electronics. This paper subjects standard superabsorbents currently used for water-blocking applications to accelerated aging tests in the hydrated state. These tests measure viscosity, flow and extrudate drainage of the hydrated gel as a function of heat aging. The results are used to rank gel stability and highlight which superabsorbent should perform best for long-term blockage. The superabsorbents degraded at various rates, from total loss of gel integrity within 24 hours to stable gel structure for at least 14 days. Given these differences in aging, it is essential to balance initial superabsorbent swelling performance with the ability of the superabsorbent to maintain water-blocking ability over time.