塑料热水管氧化稳定性及其加速试验方法

对塑料热水管是否具有50a使用寿命，需要对其进行氧化稳定性评价。根据抗氧剂遭水抽提这一主要过程设计了一套使用薄片试样的试验方法，对PP热水管材料可以在1个月以内的试验时间淘汰氧化稳定性极差的材料，可在3个月的试验时间基本肯定氧化稳定性合格的材料。当试验时间持续到更长的时间时，可提供降低材料中抗氧剂用量潜力的评价。该方法可用于塑料热水管抗氧剂配方筛选工作，也可用作塑料热水管原料及其管材制品氧化稳定性质量控制的补充方法；用来估计抗氧剂从水侧损失和从空气侧损失的相对重要性，以及提供抗氧剂组分／基材／水之间复杂的物理化学反应的线索。

Thermal Oxidation Stability of Plastics Pipes for Hot Water and Its Acceleration Testing Methods

The requirement of thermal oxidation stability of plastics pipes for hot water applications comes from 50 years' service life requirement of the pipelines. A method for the testing of sheet samples is drafted based on the process of water extraction of antioxidants.This method takes relatively short time to get assessment concerning thermal oxidation stability. For example, for PP hot water pipe materials, it takes less than one month to phase out the worst materials, less than three months to qualify the better materials and longer time to show the potential of cutting down the antioxidants concentration in the materials. The method can be used as screen test against thermal oxidation stability of plastics hot water pipe materials and an extra quality control method appended to the relevant standards of plastics hot water pipe materials and pipe products. More information can also be obtained with this method such as comparison of antioxidants depletion rates by water extraction with that by evaporation into the air and possible physicochemical reactions among antioxidants/matrix/water.