Polybenzimidazole (PBI) Molecular Weight and Mark-Houwink Equation

摘要

The molecular weight, and intrinsic viscosity of polybenzimidazole (PBI) and its phosphonylated derivatives are reported. The relationship between intrinsic viscosity [g] and weight average molecular weight (Mw) for PBI has been established in H2SO4 and DMF-LiCl. The Mark Houwink constants Kw of 5.2 10 3 mL/g, a of 0.92 for H2SO4 solvent systems and, Kw of 3.2 10 2 mL/g, a of 0.754 for DMFLiCl solvent system have been determined at Mw < 65,000. The intrinsic viscosity of PBI determined by the Huggins– Kraemer method was compared with a single point method, and found that both methods fit well for PBI in relatively low concentration solvent system, giving 99% accuracy.