测试条件对瓶级聚酯切片特性黏度的影响

比较了GB T1793 1 1999标准、ISO162 8 5 :1998和ASTM460 3 96标准的测试条件。按照GB T1793 1 1999中规定的 2种方法对样品的特性黏度进行测试。试验了溶剂体系、测试温度、计算公式及黏度计毛细管直径对黏度测试结果的影响。瓶级聚酯切片标准样品在质量比为 1 1的苯酚 邻二氯苯溶剂中测试的特性黏度结果比在质量比为 3 2的苯酚 /四氯乙烷溶剂中的结果高 0 .0 5 ;在 2 5℃与 3 0℃下测试的结果相差 0 .0 13左右 ;用 2个计算公式得出的特性黏度结果有明显差异 ;而黏度计毛细管的直径影响不大 ,d为 0 .84～ 0 .95mm能满足试验精度要求。但毛细管直径选定后 ,不要轻易改变 ,以确保系统误差稳定。

Effect of test condition on bottle grade PET chip intrinsic viscosity results

Comparision of test condition has been done among GB/T17931 1999 standard,ISO1628 5:1998 and ASTM 4603 96 standard.According to the two methods stipulated by GB/T17931-1999,test has been done on sample intrinsic viscosity.Effect of solvent system,test temperature,calculation formula and fluidmeter capillary diameter on the viscosity test results are tested.The intrinsic viscosity test result of bottle grade PET chip sample which solvent is phenol/ o dichlorobenzene (mass ratio is 1/1) is 0.05 higher than the sample which solvent is phenol/tetrachloroethane (mass ratio is 3/2),the test result is about 0.013 difference at 25 ℃and 30 ℃,the test results got from two calculate formula are significance differential.The fluidmeter capillary diameter has little effect on the test result.When d is 0.84～0.95 mm,the experiment precision requirement can be met.But when the capillary diameter is selected,it can not be changed lightly so that the system error is steady.