试管浸没甘油深度影响聚氯乙烯电缆料刚果红法热稳定试验结果的研究

Study on the Effect of Depth of Immersion Test Tube in Glycerin on the Thermal Stability of PVC Cable Material by Congo red Method

GB/T 8815—2008《电线电缆用软聚氯乙烯塑料》规定了电线电缆用软聚氯乙烯塑料200℃时热稳定时间的技术要求和试验方法。但是发现用于测试70℃产品系列及HⅠ-90电缆料的刚果红法对试管浸没甘油的深度未作具体要求。通过试验表明:试管浸没甘油的深度不同,热稳定时间不同,甚至存在对产品质量判定的重大影响,但热稳定时间随试管浸没甘油深度的增加而变化的方向并非绝对。建议GB/T 8815—2008规定出试管浸没甘油的具体深度。

GB/T 8815—2008《Plasticized polyvinylchloride(PVC)compounds for wire and cable》stipulates technical requirements and test methods of thermal stability time of at 200 degrees Celsius of plasticized polyvinylchloride(PVC)compounds for wire and cable.However,it was found that Congo red method,which was used to test 70℃product series and HⅠ-90 cable material,had no specific requirements for the depth of immersed test tube in the glycerin.The test shows that:Different depth of immersedtest tube in the glycerin,different time of thermal stability,even have a significant impact on product quality judgment,but the direction of thermal stability time changing with the increase of immersed test tube in the glycerin depth is not absolute.It is suggested that GB/T 8815—2008 specify the specific depth of immersed glycerin in the test tube.