Application of a Simon-type equation to the relationship between glass transition temperature and pressure for polymers

Takamizawa, Kanichiro; Toratani, H.; Karasz, Frank E.

doi:10.1016/0040-6031(94)87026-8

Cited by 5 publications

(1 citation statement)

References 24 publications

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“…Details of this derivation are described elsewhere. 16 The solid curves in Figure 2 are drawn by using eq 3. The least-squares fitting was obtained with a fixed value of Tgo· The Tgo value was calculated from the linear relation between Tg and the logarithm of the cooling rate at atmospheric pressure.…”

Section: Resultsmentioning

confidence: 99%

Effect of Pressure on the Relation between Glass Transition Temperature and Molecular Weight for Monodispersed Polystyrenes

Toratani

Takamizawa

1994

Polym J

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ABSTRACT:The glass transition temperatures T• of monodispersed polystyrenes possessing different number-averaged molecular weights M. were determined by high pressure DTA of up to 500 MPa. The measurements were performed using samples glassified at a cooling rate of 20 K/min -1 under differing pressures. T• was satisfactorily fitted against P according to the Simon-type equation, which is usually applied to the relation between melting points and P. The linear relation of T• against M. -1 was found to hold even under high pressure. The slope of this relation increased from 0.98 x 10 5 K at atmospheric pressure to 1.19 x 10 5 K at 500 MPa. When the slope was analyzed by means of Bueche's model, the excess free volume of the chain ends decreased with increasing pressure and seemed to have an asymptotic value above 350 MPa, which was one-third of the value at atmospheric pressure.KEY WORDS Glass Transition Temperature / Molecular Weight Dependence/ Polystyrene/ Free Volume/ Pressure/ The linear relation of Tg against Mn -l has been established for many linear polymers, ever since the fundamental work by Fox and Flory1 was published. The relation is represented by:( 1) where Tgoo corresponds to the Tg of a polymer with infinite molecular weight. The slope K represents the characteristics of the polymer chain. For monodispersed polystyrene, two studies using DTA 2 and dilatometry 3 have been reported. Although these studies were based on different properties of heat capacity and volume, and although the freezing-in rate of glassification differed greatly, the K values which were obtained were nearly identical. The difference in Tgoo could be reasonably interpreted in terms of the freezing-in rate, based on a linear correlation between Tg and the logarithm of the glassification rate. 4 , 5 It has, moreover, been noted that an almost identical value of K was also reported for the molecular weight fractions of thermally polymerized polystyrenes. 1 It is concluded that K can be used as a reliable parameter reflecting chain character.Many studies on the pressure change of Tg have been carried out, partly because they would provide information which could shed light on the intrinsic nature of polymeric glass. However, it would seem that few studies on the pressure dependence of Khave been carried out. Using high pressure DT A, we have continued to study the relation of Tg vs. Mn -l under high pressure

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Section: Resultsmentioning

confidence: 99%

Effect of Pressure on the Relation between Glass Transition Temperature and Molecular Weight for Monodispersed Polystyrenes

Toratani

Takamizawa

1994

Polym J

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Relation between the adhesion strength and interfacial width for symmetric polystyrene bilayers

Akabori

Baba

Koguchi

et al. 2006

J Polym Sci B Polym Phys

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Polystyrene (PS) bilayers were prepared and were adhered at a temperature between the surface and bulk glass-transition temperatures for a given time. Then, the interfacial adhesion strength (G L ) was examined with a conventional lapshear measurement. G L first increased with increasing adhesion time and then reached a constant value. This result implied that the segments moved across the interface, to a certain depth, even at a temperature below the bulk glass-transition temperature. To confirm this, the interfacial evolution for the PS/deuterated PS bilayers was examined with dynamic secondary-ion mass spectrometry. The G L value was linearly proportional to the thickness of the interfacial adhesion layer. Finally, we propose a strategy for regulating the adhesion strength based on the chain-end chemistry.

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Investigation on the solidification of several pure cyclic and aromatic hydrocarbons at pressures to 300MPa

Liu

Bamgbade

et al. 2013

Fuel

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Application of a Simon-type equation to the relationship between glass transition temperature and pressure for polymers

Cited by 5 publications

References 24 publications

Effect of Pressure on the Relation between Glass Transition Temperature and Molecular Weight for Monodispersed Polystyrenes

Effect of Pressure on the Relation between Glass Transition Temperature and Molecular Weight for Monodispersed Polystyrenes

Relation between the adhesion strength and interfacial width for symmetric polystyrene bilayers

Investigation on the solidification of several pure cyclic and aromatic hydrocarbons at pressures to 300MPa

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