BUBBLE INFLATION TECHNIQUE FOR THE MEASUREMENT OF VISCOELASTIC PROPERTIES IN EQUAL BIAXIAL EXTENSIONAL FLOW - 2.

Abstract

Additional data are presented for a bubble inflation technique which was used to develop equal biaxial extensional flow in viscoelastic materials. Biaxial extensional viscosity and elastic properties of a polyisobutylene at 23 C are compared with the predictions of constitutive equations and with experimental results obtained from other instruments. Constant pressure experiments were carried out to the point of bubble bursting. A modified plot involving variables derived from pressure and bursting time is compared with the biaxial viscosity data, and the prospects for using this simpler test are discussed.