Determining polymer molecular weight distributions from rheological properties using the dual-constraint model

摘要: Although multiple models now exist for predicting the linear viscoelasticity of a polydisperse polymer from its molecular weight distribution (MWD) and inverting this process by MWD rheology, such inverse predictions do not yet long-chain branched polymers. Here, we develop test method dual-constraint model (Pattamaprom et al., Rheol Acta 39:517–531, 2000; Pattamaprom Larson, Macromolecules 34:5229–5237, 2001), that is able to predict rheology star-branched As first step, apply only polymers, comparing experimental GPC traces. We show these are usually at least as good, or better than, obtained Doi–Edwards double-reptation (Tsenoglou, ACS Polym Prepr 28:185–186, 1987; des Cloizeaux, J Europhys Lett 5:437–442, 1988; Mead, 38:1797–1827, 1994), which take “benchmark”—an acceptable invertible By changing predefined type log normal, has two fitting parameters, GEX, three slightly improved. These results suggest complex enough can be inverted, obtain distribution. Further work will required invert allow prediction