Critical considerations for the accelerated ageing of high-density polyethylene potable water materials

摘要: Accelerated ageing conditions with chlorinated water were identified that minimize variations in solution chemistry and sorption, also enable the interpretation of HDPE physical chemical changes during 20 week (3884 h) immersion periods. Of ten tested, three an alkalinity concentration 50 ppm as CaCO3 at pH 6.5 23 37 � C performed best. These exhibited stable pH, free available chlorine, weeks 72 h solution. was periodically characterized using differential scanning calorimetry, thermogravimetric analysis, tensile a density gradient column, moisture optical infrared spectroscopy. Formation surface carbonyl bonds gradual reductions oxidation induction time detected, well sorption into HDPE. Ageing monitoring recommendations from this work should be incorporated accelerated protocols considered when characterizing aged PE drinking pipe. 2009 Published by Elsevier Ltd.