Dynamic osmotic pressure measurements on low molecular weight polymers

Feist, William C.

doi:10.1002/pol.1965.110031017

Cited by 7 publications

(2 citation statements)

References 5 publications

(4 reference statements)

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“…There are experimental methods for determining the molecular weights of polymers. Osmotic pressure6, 7 and intrinsic viscosity ([η])8–12 methods are used for the determination of M n 13, 14. Sedimentation,15, 16 diffusion,17–19 and light scattering20–24 methods are suitable for the determination of M w .…”

Section: Introductionmentioning

confidence: 99%

Measurement and modeling of poly(vinyl acetate)–solvent viscosity mixtures

Modarress

Mohsen-Nia

2005

J of Applied Polymer Sci

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ABSTRACT:The viscosities of various poly(vinyl acetate) (PVAc)-solvent mixtures (PVAc-toluene, PVAc-benzene, and PVAc-cyclohexanone) were measured at different temperatures with a Haake viscometer. The required molecular weight of a commercial-grade PVAc sample was measured with an Ubbelohde viscometer. The measured viscosities were correlated with a previously proposed viscosity model, and the model parameters were calculated. The results indicated the applicability of the model to the viscosity calculations of PVAc-solvent mixtures.

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Section: Introductionmentioning

confidence: 99%

Measurement and modeling of poly(vinyl acetate)–solvent viscosity mixtures

Modarress

Mohsen-Nia

2005

J of Applied Polymer Sci

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“…Papers have also been published dealing with general aspects of osmometer design (64) and methods by which osmometers with semipermeable membranes can be employed to determine molecular weights of the order of magnitude of that of the solvent (105). Dynamic osmometry has been reported to be useful for polymers with molecular weights of 1200 and up (76). The preparation of very tight membranes useful down to molecular weights of 500 has been described (221).…”

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confidence: 99%

Rubber

Wadelin¹,

Trick²

1967

Anal. Chem.

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Diffusion, membrane selectivity, and nonequilibrium effects in rapid membrane osmometry

Ghosh¹,

Swenson²

1968

J of Applied Polymer Sci

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SynopsisItapid membrane osmometry, narrow distribution polystyrenes in the range 4000-700,000, and three membrane types of different porosity were used to study the effects of diffusion and of Staverman membrane selection in osmometry. It was found that equilibrium was not obtained in the rapid measurement with the two densest membranes which led to grossly low values for the high molecular weight sample but had small effect at low molecular weights. Because of membrane selectivity effects at lower, and of nonequilibrium effects at higher molecular weights, the effective range was about 4000-350,000 for the densest membrane, 90,000-500,000 for the medium porosity membrane and from 146,000 to an unrestricted tipper limit for the grossest membrane. A unique characlerislic of the Mechrolab 601 instrument used in the study is the small constanL volume on the solvent side of the membrane which allows determination of t,he osmotic pressure of t,he diffused material and its concentration when the molecular weight is known. Iliffusion can be avoided if t,he pressure reading is taken quickly enough but membreiie selectivi1,y effeck cannot8 be avoided if diffusible solute is present. Enormous seleclivi1.y effect,s were found when mixtures of diffusible and nondiff wible molecules were measured. Experimentd value-; of the selectivity coelficient S, of the mixtures were Eoiuid t,o agree closely with those calctilaLed from the Staverman equat,ions. Estimates of the coil size of the polymers are given to provide an estimate of the effective porosities of the membranes.

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Dynamic osmotic pressure measurements on low molecular weight polymers

Cited by 7 publications

References 5 publications

Measurement and modeling of poly(vinyl acetate)–solvent viscosity mixtures

Measurement and modeling of poly(vinyl acetate)–solvent viscosity mixtures

Rubber

Diffusion, membrane selectivity, and nonequilibrium effects in rapid membrane osmometry

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