Computer-aided phase modulated flow birefringence experiment on polystyrene solutions

Abstract

A rheo-optical experimental apparatus based on Phase-Modulated Flow Birefringence (PMFB) has been developed. This PMFB methdo is one of the most powerful technique to study rheological behaviors of the polymer systems. Using this PMFB system, flow birefringence measurements can be performed in transient from conditions with obtaining birefringence n and orientation angle of the sample simultaneously in time. A useful computer-aided system which has the capability of controlling the flow dynamics, detection and data acquisition has been developed. Also a new mathematical calculation method to obtain the birefringence with less error propagation has been established. This computerized system for PMFB technique has been carefully checked by the quarter wave plate calibration and proved to be reasonable. Moreover, to make validate our computer sysem, the experiments for investigating the molecular weight effect on the optical properties of 1.5 wt\% of Polystyrene solution have been performed. The results of this experiments were well fitted to the general theories and the data of other researchers.