聚丙烯老化过程光学性质变化的研究

Changes of optical properties in the aging process of polypropylene

中文关键词:  食品接触材料  聚丙烯  热氧老化  光学性质

英文关键词:food contact materials  polypropylene  thermal oxygen aging  optical properties

中文摘要:

      目的 研究聚丙烯餐具黄色指数、透明度等光学性质的变化规律。方法 通过热氧加速老化实验分析不同使用温度下聚丙烯餐具特殊基团数量的变化。结果 聚丙烯在热氧老化过程中当老化温度为120 ℃, 老化时间从0 h到504 h, 羰基指数增大了7%, 黄色指数增大了29.8%, 透明度减小了5.9%; 老化温度为125 ℃, 老化时间从0 h到504 h, 羰基指数增大了26%, 黄色指数增大了61.5%, 透明度减小了6.8%; 老化温度为130 ℃, 老化时间从0 h到504 h, 羰基指数增大了69%, 黄色指数增大了82%, 透明度减小了11.6%。结论 聚丙烯老化过程中随着老化时间的延长、老化温度的升高, 羰基指数增加, 色差和黄色指数增大, 透明度减小, 光学性质发生了变化, 可以将光学性质作为表征材料老化规律及寿命预测的参考因素之一。

英文摘要:

      Objective To investigate the changes of optical properties (yellow index, transparency) in the aging process of polypropylene tableware. Methods The optical properties including yellow index and transparency were studied by analyzing the changes of the number of special groups of polypropylene cutlery under different temperatures during thermal oxygen accelerated aging test. Results In the polypropylene thermal aging process, when the aging temperature was 120 ℃, and aging time was from 0 h to 504 h, carbonyl index increased 7%, yellow index increased 29.8%, and transparency decreased 5.9%, respectively. When the aging temperature was 125 ℃, and aging time was from 0 h to 504 h, carbonyl index increased 26%, yellow index increased 61.5%, and transparency decreased 6.8%, respectively. When the aging temperature was 130 ℃, and aging time was from 0 h to 504 h, carbonyl index increased 69%, yellow index increased 82%, and transparency decreased 11.6%, respectively. Conclusion With the increasing of aging time and aging temperature, the carbonyl index increased, color and yellow index increased, and transparency reduced in the polypropylene thermal aging process. The optical properties of polypropylene aging process had changed. Optical properties could be used as one of reference factors in characterization of materials aging and life prediction.