Statistical Theories as Applied to the Glassy State

Anderson, Orson L.; Stuart, D. A.

doi:10.1021/ie50529a047

Cited by 16 publications

(2 citation statements)

References 7 publications

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“…584); turbulence (558); viscosity of glasses(554); non-Newtonian fluids(565); polymers(561); relaxation theory(569,572); the superposition approximation(573); ultrasonic absorption(570,578); empirical or semi-empirical formulas for viscosity(556, 564, 579, 580). The author thanks Drs.…”

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confidence: 99%

Theories of Liquid Viscosity.

Brush¹

1962

Chem. Rev.

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mentioning

confidence: 99%

Theories of Liquid Viscosity.

Brush¹

1962

Chem. Rev.

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“…Several investigators, including Douglas [ 14 ], Cox [ 15 ], and Hodgdon and Stuart [ 16 ] have discussed equations for relating viscosity and temperature, but, as pointed out by Anderson and Stuart [ 17 ], these equations in each case reduce to 4-constant equations comparable with a dual writing of eq (1) , once for high temperatures and again for low temperatures.…”

Section: Viscosity Datamentioning

confidence: 99%

Vitrons as flow units in alkali silicate binary glasses

Tilton¹

1961

J. RES. NATL. BUR. STAN. SECT. A.

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(Nove mber 23, 196 1) Two volum e-cha ngi ng processes found useful in stud yin g t he m echanis m of viscous flow in glasses a re : (a) stress-indu ced variation in fi ss ming near "itrons at t heir p eripheries w here the Si-O bonds a re te nsed and weakened , a nd (b) di sten t ion and modification of a ll s ilica n etwork by add ed oxides. These ideali zed processes, readily d eri vable from t he vit roll concept of pentagonal rin g struc t ure in glass (1),2 a re sensitive to both temperat ure an d composition a nd have previously been found useful [1 , 2, 3, 4, 5] for understandin g other p roperties of glasses.Vi sco us flow of vi trons as units in an nealing ranges, and at hi g her processing temperat ures for s ili ca-rich glasses, is here viewed as permitted prim ari ly by t h e breaking of te nsed and weakened Si-O bonds in s hell-like stressed t iss ues surrounding vitrons. For modificrrich glasses at high temperatures, where t he activation energy of flow is known to be low for a l kali silicates but slight ly higher for a lka line ear ths, t he s hearin g of cation-to-oxygen bonds may also be involved . The fi s ures between vitrons and m atrix network m ay provide fr ee volume for cooperative man euvers a mong t he vitrons.At high processing te mper atures, bot h viscosity and activation energy of flow are known to deCl'ease monotonicall y and at first wit h extre me rapid ity as t he content of modifi ers increases. This is understand able if even slight modification materi a ll y decreases t h e local pliabili ty of t he matri x n etwork and oxide-volume expansio n progressivel y widens t he fi ss ures t hat must be created at vitroll p eripheries where t he radial contraction of vitron growth potential is chec ked by tangential Si-O bond str esses .On coolin g toward ann ealing te mperat ures, t he observed rapid increases in viscosity a nd i n acti vation energy of flow a re here ascribed to a general tendency toward narrowi ng of peripheral fiss ures, with stronger bonds t herei n, as t he di stort ed dodecahedral cage ret urn toward symmetr y in r esponse to t he increases in 0-0 r epulsion s. Such repulsions increa e with extreme rapidity if ionic sep arations become s ma ller t han equilibrium dista nccs.N ear t he a nnealing ranges where it beco mes necessar y to hold glasses at constant te mpcratures for apprecia ble t im es in order to observe flow of the hi gh-temperat ure type, i t is noticeable t hat t he activation cnergy of How increases as t he content of modificrs increa es. This s uggests t hat t he closure of fi ss ures at t hese very low processin g te mpcraLure may be more effective in preven ting cooperative m aneuvers t han in r esealing t he w eak a nd brokcn Si-O bonds.Below a nnealing temperatures, where t he read ily observed viscosities become somewhat higher while t he activation energies d ecrease very rapidly, it is suggested t hat t he character o f fl ow is changing un til fin ally t her e are possible onl y volume relaxations with su ch sm all relative movem...

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Mechanical aspects of polymer blending

Kausch¹

1991

Makromolekulare Chemie. Macromolecular Symposia

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“Improving through mixing” is a fundamental human concept; as applied to polymers, there are thermodynamic, processing related and mechanical obstacles. In this paper some mechanical consequences of structural heterogeneity on a molecular and microscopic level are discussed. The second aspect to be treated is that of the molecular mechanisms contributing to deformation and fracture, especially void formation, crazing, and shearbanding. To develop these ideas, reference to two systems will be made, a core‐shell particle modified polyamide and an epoxy resin.

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Statistical Theories as Applied to the Glassy State

Cited by 16 publications

References 7 publications

Theories of Liquid Viscosity.

Theories of Liquid Viscosity.

Vitrons as flow units in alkali silicate binary glasses

Mechanical aspects of polymer blending

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