Extensional viscosity of a thermotropic liquid crystalline polymer measured by thread disintegration method

We investigated a simple method for measuring the extensional viscosity of thermotropic liquid crystalline polymer: disintegration of liquid crystalline polymer threads in a quiescent polymer matrix. The method is based on the dynamic interfacial tension between the two components, and covers strain-rate and strain ranges that are very low. Results obtained by the method show extensional rate thinning behavior and strain-hardening behavior. The trends are in agreement with previous measurements using other methods such as fiber spinning. We recommend the thread disintegration method for measuring extensional viscosity at small extensional rates and small strains.