Laser light scattering characterization of molecular weight distribution of worm-like chains poly(1,4-phenylene terephthalamide) in concentrated sulfuric acid

Abstract

By combining static and dynamic light scattering measurements, we have succeeded in determining the molecular weight distribution of poly(1,4-phenylene terephthalamide) in concentrated sulfuric acid using Laplace inversion of the photoelectron autocorrelation function. The complex method of data analysis can be greatly simplified for on-line monitoring purposes by measuring the difference correlation functions whereby changes of molecular weight and of polydispersity can be detected quantitatively by photon correlation measurements at a fixed scattering angle and finite concentration even for worm-like chains. Effects due to concentration, intramolecular interference, and internal motions can be taken into account in the empirical procedure.