The effects of solvents and temperature on thermoplastic hose for umbilical service are reported in this paper. Accelerated ageing tests were undertaken and analysed by gravimetric, mechanical and calorimetric measurements. Water and methanol were found to cause physical degradation of the polymer, mainly at high temperatures, whereas xylene caused chemical degradation, which increased with increasing temperature. The activation energy for the a-process within polyethylene (PE) was found to be 96.3 kJ mol{sup}(-1) for un-aged PE and increased to 106.2 kJ mol{sup}(-1) after 64 days of ageing in water at 100°C. The changes in activation energy will be used to make a life-time prediction of umbilical lines.
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