Pressure‐volume‐temperature behavior of polypropylene

Foster, George N.; Waldman, Nathan; Griskey, Richard G.

doi:10.1002/pen.760060208

Cited by 37 publications

(19 citation statements)

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“…We used data for the isothermal compressibility of PE-L, PE-H, and PS obtained by Hellwege, Knappe, and Lehmann,3 of PTFE obtained by Weir4, and of PP obtained by Foster, Waldman, and Griskey. 5 The dielectric constant s of a polymer sample 750 was calculated from observed capacitance C [pF], according to the relation…”

Section: Methodsmentioning

confidence: 99%

Effects of Temperature and Pressure on the Dielectric Constant in Non-Polar Polymers

Sasabe

Saito

1972

Polym J

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ABSTRACT:Changes of dielectric constant e. : in non-polar and slightly polar polymers with temperature and pressure have been analyzed in terms of the Clausius-Mossotti equation. It is concluded that the Clausius-Mossotti equation is valid for polyethylene but should be modified and expressed in the form M(e.:-l)/p(e.:+2)=(4rrN0/3) x (a+ µ 2 /3kT) for slightly polar polymers. It is also concluded from the comparison of the polarizability a for low-molecular-weight substances with a for polymers that the determining factor for a for polymers is the molecular structure of the monomer unit. os/oT and os/oP change suddenly at a transition point such as glass transition (Tg) and phase transition in the crystalline region (Tx), and dTg/dP for polystyrene can be evaluated as 3.2 x 10-2 K atm-1 and dTx/dP for poly(tetrafluoroethylene) as 2.3 x 10-2 Katm-1 • KEY WORDS Dielectric Constant / Clausius-Mossotti Equation / Polarizability / Glass Transition / Crystalline Phase Transition / Polystyrene / Poly(tetrafluoroethylene) / Studies on the dielectric properties of polymers as functions of temperature and pressure may be roughly divided into two categories: (1) dielectric relaxations associated with molecular motions of polymer chains and (2) limiting highand low-frequency dielectric constants of polymers. The former category (1) has been vigorously investigated over these last several years. 1 According to those investigations it has been made clear that temperature and pressure dependences of dielectric relaxations in polar polymers can be interpreted by those of free volume, cofigurational entropy and/or intermolecular interactions. On the other hand, category (2) has not been sufficiently investigated as yet.Studies on effects of temperature and pressure on limiting high-frequency dielecric constant s= of polymers is of particular interest, since s= is an important quantity for the evaluation of dielectric increments and is closely related to the optical refractive index. Non-polar polymers whose dielectric constant s is independent of frequency and corresponds to s= in polar polymers are suitable for such a study. .In this paper we will discuss the changes of s in nonpolar and slightly polar polymers such as polyethylene, poly(tetrafluoroethylene ), polypropylene, and polystyrene, with temperature and pressure from the view-point of the molecular structure (that is, the check of the ClausiusMossotti equation), and their correlations with transition phenomena in polymers.While non-polar dielectric materials have no permanent dipoles, 'electronic and atomic polarizations (or, more exactly, optical and infrared polarizations) are induced by the application of an external electric field. Contributions of these induced dipole moments to the dielectric constant are expressed by the well-known Clausius-Mossotti equation,where M is the molecular weight, p the density, N 0 Avogadro's number, a the polarizability, and, in the case of polymers, M is the molecular weight of a monomer unit and a is the polarizability of a monom...

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Section: Methodsmentioning

confidence: 99%

Effects of Temperature and Pressure on the Dielectric Constant in Non-Polar Polymers

Sasabe

Saito

1972

Polym J

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“…Foster et al [18] have used a cylinder-piston-type method in a compressibility chamber to acquire PVT data by multiplying the cross-sectional area of the pistion with the linear displacement of the piston. Ender [19] has used the coil of a linear variable differential transformer (LVDT) to measure the volume swelling of various elastomers under high pressures in CO 2 at relatively low temperatures.…”

Section: Introductionmentioning

confidence: 99%

“…Attempts have been made to measure polymer swelling under high-pressure gas conditions [17][18][19][20][21], in which the change in the dimension of a polymer sample was recorded. Foster et al [18] have used a cylinder-piston-type method in a compressibility chamber to acquire PVT data by multiplying the cross-sectional area of the pistion with the linear displacement of the piston.…”

Section: Introductionmentioning

confidence: 99%

Measurement of the PVT property of PP/CO2 solution

Park

et al. 2008

Fluid Phase Equilibria

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“…(1) polytetrduoroethylene; (8) poly(methy1 methacrylate); (8) polypropylene; ( 4 ) poly(vinylidene fluoride); (6) poly(viny1 fluoride); (6) poly(viny1 chloride); (7) poly-(vinyl alcohol); (8) polystyrene; (9) polychlorotrifluoroethylene; (10) low density polyethylene; (11) high density polyethylene; (-) base curve.…”

Section: Reduced Temperaturementioning

confidence: 99%

A generalized equation of state for polymers

Whitaker

Griskey

1967

J of Applied Polymer Sci

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SynopsisA simple, generalized equation of state has been developed that describes the pressurevolume-temperature behavior of both addition and condensation polymers. Use of the equation requires only that the polymer's glass temperature and density at 25OC. and one atmosphere be known. The equation applies to both amorphous and crystalline polymers for pressures up to 10,000 atm. It also appears to bold for copolymers. Polymer glass temperatures can also be estimated with the equation.The pressure-volume-temperature behavior of polymers is a subject of oonsiderable importance to polymer engineers and scientists. Equally important is the need for an equation of state which will suitably describe this behavior. Such an equation should meet several standards. First of all, it must be applicable over wide ranges of temperature and pressure. Next, it should be as general as possible. In addition it should be simple and easily used. Finally, it should be able to predict the behavior of polymers for which no data are available.Several polymer equations of state exist. Unfortunately, these fail to meet one or more of the above standards.The oldest of these equations was that developed by Spencer and Gilmore.' This equation was a form of the van der Waals equation containing three constants. It had to be fitted to the pressure-volumetemperature data for each individual polymer. This meant that different constants were obtained for each polymer. The equation then was not general and furthermore it could not be used to predict the behavior of polymers for which data were not available. The same deficiencies applied to a virial type of equation developed by Weir.2p3More recently two investigators, Flory4 and Di B e n e d e t t~,~ have attempted to use quantum mechanics to describe the pressure-volumetemperature behavior of polymers. Flory developed an equation which he applied to long chain hydrocarbons (with repeating units up to 40). His equation was never applied to polymers. Furthermore, he indicated that the equation did not too satisfactorily describe the hydrocarbon behavior over wide temperature and pressure ranges.Colorado 80210.

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Pressure‐volume‐temperature behavior of polypropylene

Cited by 37 publications

References 13 publications

Effects of Temperature and Pressure on the Dielectric Constant in Non-Polar Polymers

Effects of Temperature and Pressure on the Dielectric Constant in Non-Polar Polymers

Measurement of the PVT property of PP/CO2 solution

A generalized equation of state for polymers

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