The use of parallel plate rheology to determine the intrinsic viscosity of polyethylene terephthalate
Determining the intrinsic viscosity of polyethylene terephthalate is complicated by the fact that there are only two methods available at present. The first method is based on solution viscosity. The toxicity of the solvent, as well as the time it takes to carry out an analysis, results in this method not being very practical for everyday use. The second method is limited in its application due to the complexity and availability of the equipment in South Africa. In the present study an alternative method, based on parallel plate rheology, is presented. This method overcomes the problems mentioned and results obtained with it are compared with results obtained with the methods in use at present.