Determination of molecular weight and its distribution of flexible chain polymer by phase-modulated flow birefringence technique

Abstract

The objective of this study is to develop a systematic method to determine molecular weight and its distribution of flexible chain polymer by birefringence experiments. Using the random walk model, birefringence Deltan and orientation angle chi have been optically obtained as functions of molecular weights. To confirm the theory, polystyrene solutions with different molecular weights dissolved in polychlorinated biphenyl were experimented by the phase-modulated flow birefringence (PMFB) method. Birefringence of polystyrene solutions is proportional to (Sigmac(i)M(i)(1.6))gamma(2) and cot(2chi) to (Sigmac(i)M(i)(16)/B(1)Sigmac(i)M(i)(-0.2))gamma. The experimental resets agreed well with the theoretical predictions proposed in this study.