食品包装瓶用PET树脂乙醛含量测定结果的影响因素研究

Research on influencing factors on determination of acetaldehyde content in polyethylene terephthalate resin used for food packaging bottle

中文关键词:  聚对苯二甲酸乙二醇酯树脂  乙醛  氮气  水分  粉碎时间  粒径

英文关键词:polyethylene terephthalate resin  acetaldehyde  nitrogen  water  crushing time  particle diameter

中文摘要:

      目的 探究氮气、水分、粉碎时间、粒径对食品包装瓶用聚对苯二甲酸乙二醇酯(PET)树脂粒子中残留乙醛含量测定结果的影响。方法 根据SH/T 1817-2017《瓶用聚对苯二甲酸乙二醇酯(PET)树脂中残留乙醛含量的测定顶空气相色谱法》, 采用控制变量法, 考察氮气吹扫顶空瓶、样品含水量、粉碎时间、粒径对瓶用PET树脂粒子乙醛含量测试结果的影响。结果 经过氮气保护的测试结果高于未经氮气保护的测试结果; 含5、10、15 μL蒸馏水试样的测试结果高于干燥样品的测试结果, 且含水量越大测试结果越大; 粉碎时间对测试结果的影响不明显(P=95%); 粒径越小测试结果越大。结论 测试食品包装瓶用PET树脂粒子乙醛含量时, 样品须用氮气保护且保持干燥状态, 以获得准确的测试结果。建议SH/T 1817-2017中对于试样粒径的要求进一步细化, 以提高测试方法的统一性。

英文摘要:

      Objective To investigate the effects of nitrogen, water, crushing time and particle diameter on determination of acetaldehyde content in polyethylene terephthalate (PET)resin used for food packaging bottles. Methods According to SH/T 1817-2017 Plastics-Determination of residual acetaldehyde in polyethylene terephthalate (PET) resin for bottles-Headspace gas chromatography, the controlled variable method was used to investigate the effects of nitrogen purging the headspace bottle, the water content of sample, different crushing time and different particle diameter on the test results of acetaldehyde content of PET resin particles used in bottles. Results The test results with nitrogen protection were higher than those without nitrogen protection. The test results of samples with 5, 10, 15 μL distilled water were higher than those of dry samples, and with the greater the water content, the greater the test results were. The impact of the crushing time on the test results was not obvious (P=95%).The test result became larger as the particle size became smaller. Conclusions When testing the acetaldehyde content of PET resin particles used in food packaging bottles, the samples should be protected by nitrogen and kept dry to obtain accurate test results. It is suggested that the particle size requirement of the standard SH/T 1817-2017 should be further refined to improve the uniformity of the test method.