Molecular weight prediction in polystyrene blends. Unprecedented use of a genetic algorithm in pulse field gradient spin echo (PGSE) NMR

A genetic algorithm that uses boxcar functions (diffGA) has been applied for the first time in PGSE NMR.

Correction: Molecular weight prediction with no dependence on solvent viscosity. A quantitative pulse field gradient diffusion NMR approach

Correction for ‘Molecular weight prediction with no dependence on solvent viscosity. A quantitative pulse field gradient diffusion NMR approach’ by Francisco M. Arrabal-Campos, et al., Polym. Chem., 2016, 7, 4326–4329.

Molecular weight prediction with no dependence on solvent viscosity. A quantitative pulse field gradient diffusion NMR approach

To progress on the practical issues of molecular weight prediction via diffusion NMR, the first log(Dη) vs. log(Mw) calibration curve is provided, allowing the easy and fast determination of weight-average molecular weights with no matter of the solvent used.

Quarternization of 3-azido-1-propyne oligomers obtained by copper(I)-catalyzed azide–alkyne cycloaddition polymerization

3-Azido-1-propyne oligomer (oligoAP) samples, prepared by copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) polymerization, were quarternized quantitatively with methyl iodide in sulfolane at 60 °C to obtain soluble oligomers. The conformation of the quarternized oligoAP in dilute DMSO-d 6 solution was examined by pulse-field-gradient spin-echo NMR based on the touched bead model.