| Popis: |
Accurate molecular weight characterization of PVC is necessary before attempting to modify the properties of the polymer using additives and/or process the compound in some fashion. Commercial PVC resins are characterized by many different dilute solution viscosity methods. Manufacturers characterize their resins using K values, specific viscosity, relative viscosity, viscosity numbers, and inherent viscosity. Each of these methods can vary according to solvent used, testing temperature, and resin concentration. This paper reviews the technical literature and information published by the major PVC resin producers regarding molecular weight characterization. The information in this review should be useful for scientists and engineers in the PVC industry to translate between and among the various test methods for molecular weight characterizations. |
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