On the Molecular Weight Distribution in Degraded Polymers

Molecular Weight Profiles of Proanthocy Anidin Polymers

The MW profiles of proanthocyanidin polymers (condensed tannins) from 32 samples representing a wide range of plant tissues of many different species have been obtained by gel permeation chromatography of the peracetate derivatives. The tannins vary widely in MW, with Al. values for the peracetates in the range 1600-5500. The MW profiles vary greatly from those with narrow, rather smooth distri...

The gamma distribution model for pulsed-field gradient NMR studies of molecular-weight distributions of polymers.

Self-diffusion in polymer solutions studied with pulsed-field gradient nuclear magnetic resonance (PFG NMR) is typically based either on a single self-diffusion coefficient, or a log-normal distribution of self-diffusion coefficients, or in some cases mixtures of these. Experimental data on polyethylene glycol (PEG) solutions and simulations were used to compare a model based on a gamma distrib...

the impact of e-readiness on ec success in public sector in iran the impact of e-readiness on ec success in public sector in iran

acknowledge the importance of e-commerce to their countries and to survival of their businesses and in creating and encouraging an atmosphere for the wide adoption and success of e-commerce in the long term. the investment for implementing e-commerce in the public sector is one of the areas which is focused in government‘s action plan for cross-disciplinary it development and e-readiness in go...

Rheological Method for Determining Molecular Weight and Molecular Weight Distribution

Gel Permeation Chromatography . I . A New Method for Molecular Weight Distribution of High Polymers

Polystyrene gels crosslinked in the presence of dilucnts have been iliatie in tinc-iiii.sli bead forni suitable for packing into chromatographic rolurnns. A series of narrow molecular weight range pol) mer fractions w&s eluted through such columns with aromatic and chlorinated solvents. EfHuent concentrations were detected and recorded by a continuous differential refractoineter. The fractions ...