Pressure-volume-temperature properties of amorphous polymers: empirical and theoretical predictions

Simha, Robert; Wilson, Phillip S.; Olabisi, Olagoke

doi:10.1007/bf01498686

Cited by 89 publications

(45 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our larger values of f:J.K are determined from the Tait parameters given in ref. [53], which apply to the data of Hellwege et al [47]. Note that the values of d7i /dP from reevaluating [53] their data are in good agreemenf with most of the others on the same polymers except for PMMA.…”

Section: Densification Rates From Pvt Datamentioning

confidence: 66%

See 1 more Smart Citation

Thermodynamics of the densification process for polymer glasses

McKinney¹,

Simha²

1977

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

Self Cite

View full text Add to dashboard Cite

A qua ntita tive d esc riptio n is g ive n for the dens ifi cati on process of glasses resulting from g lass [orma ti o n at ele vat ed pressures . Phe nome n olog ica l re lati ons a re de rived, or j us tifie d , whic h al low es tim ati on of th e de ns ifi calion rate K ' (with respect 10 formation pressure ) fro m variolls the rmodynami c q uantiti es a nd glass trans ition be hav ior. In addition, the estimatio n of K ' may be fac ilit a ted by the appl ic a ti on of the hol e theory of S imha and Somcyn s ky. Using these relations K' is estimated , and the results from the d ifferent me thods a re co mpared for data from 23 diffe re nt organi c poly me rs wi th g lass tra ns iti on te mpe ratures rang ing fro m 150 to 455 K. T he a mount of de ns ifi cati on appea rs to be limit ed by the appa re nt convergence o f the glass tempe rature a nd e ffective decompos ition tempe rature wi th in c reas ing pressure . Some estimates of limiting values are presente d. final ly, c hanges of refrac tive index resulting from de ns ification are estima ted from the observed, or predic ted , de nsific atio n ra tes.Key words: Compress ibilit y; densifi cati on; glass; glass trans iti on ; liquid ; po lyme r; pressure; PVT; pyro lys is; re fractive index; the nna l ex pa ns ion ; thermodynami c.

show abstract

Section: Densification Rates From Pvt Datamentioning

confidence: 66%

“…[53], which apply to the data of Hellwege et al [47]. Note that the values of d7i /dP from reevaluating [53] their data are in good agreemenf with most of the others on the same polymers except for PMMA. This discrepancy would be increased by using their value of f:J.K given in ref.…”

Section: Densification Rates From Pvt Datamentioning

confidence: 66%

Thermodynamics of the densification process for polymer glasses

McKinney¹,

Simha²

1977

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

Self Cite

View full text Add to dashboard Cite

show abstract

“…Reducing parameters T*, V* and P* were calculated as follows [11][12][13][14][15]. First, substituting P = 0 into equation (4) and numerically solving equation (5), a theoretical curve of temperature dependence of the specific volume at normal pressure was constructed a comparison of which with the experimental isobars ( fig.…”

Section: Discussionmentioning

confidence: 99%

Structure-property relationships for carbochain fluoropolymers

Privalko¹,

Tarara²

1985

Colloid & Polymer Sci

View full text Add to dashboard Cite

Polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF) and polychlorotrifluoroethylene (PCTFE) were studied by differential calorimetry at normal pressure in the temperature interval 130-555 K, and by pressure dilatometry in the temperature interval 303-545 K and in the pressure range 14-70 MPa. Pressure derivatives of the melting temperature, ClTm/ClP, were used to calculate the "true" meking entropy A 8~ from the Clausius-Clapeyron equation, while equilibrium values of the mek specific volume were treated according to the Simha-Somcynsky cell theory. Comparison of the experimental data for PVF, PVDF and PCTFE with pertinent published data for polyethylene (PE) and polytetrafluoroethylene (PTFE) showed that a steady decrease of A S~ and of the conformational contribution to A Sm reflects the increase of the equilibrium chain stiffness as the hydrogen atoms of the hydrocarbon chain (PE) are substituted with bulkier fluorine and/or chlorine atoms (PCTFE, PTFE), while a concomitant drop of the pressure reducing parameter from the cell model and an increase of melt compressibility and the derivati'ce, clT,~lclP, should be attributed to the increase of the free volume fraction of the melt in the series, PE to I~FE.

show abstract

“…As shown in Figure 1, the modified two-domain Tait model [6], which is commonly used to describe the PVT data, includes a strong inflection at the phase transition line for semi-crystalline materials. As the polymer cools, this phase transition line is followed by a period of strong contraction over a fixed temperature range.…”

Section: Semi-crystalline Polymersmentioning

confidence: 99%