Molecular weight dependence of the cloud-point curve of poly(dimethylsiloxane)/poly(methylethylsiloxane) mixtures

Horiuchi, Hiroo; Irie, Shunsuke; Nose, Takeru

doi:10.1016/0032-3861(91)90160-k

Cited by 15 publications

(11 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The values of A and B in Equation (1) are very close to those reported earlier by Horiuchi et al (1991) and Meier et al (1992). For the sake of comparison the dependence of χ on temperature reported by Horiuchi et al (1991) is also plotted in Figure 5. These authors determined the binodal phase separation temperatures under equilibrium conditions, using cloud point measurements.…”

Section: Phase Diagram Of Pdms/pems Blendssupporting

confidence: 84%

“…For the sake of comparison the dependence of χ on temperature reported by Horiuchi et al (1991) is also plotted in Figure 5. These authors determined the binodal phase separation temperatures under equilibrium conditions, using cloud point measurements.…”

Section: Phase Diagram Of Pdms/pems Blendsmentioning

confidence: 99%

“…Both components have extremely low glass transition temperatures (T g, P D M S = -125°C and T g,PEMS = -132°C), therefore, T g and the dynamic asymmetry (which are common problems in many polymer blends) are not interfering with the phase separation mechanism. Moreover, adequate knowledge of the equilibrium phase behaviour and dynamics of PDMS/PEMS blends exists (Horiuchi et al, 1991;Enders et al, 1996;Fytas et al, 1996;Meier et al, 1992Meier et al, , 1993Theobald and Meier, 1995). Table 1 lists the characteristics of all materials used.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Interrelations between Rheology and Phase Behaviour in Partially Miscible Blends: The Case of Polydimethylsiloxane/Polyethylmethylsiloxane (PDMS/PEMS)

et al. 2002

View full text Add to dashboard Cite

A rheological study of the phase behaviour and the dynamics in the immiscible region of a model partially miscible Upper Critical Solution Temperature (UCST) blend was carried out by using a series of nearly monodisperse polydimethylsiloxane (PDMS) of varying molecular weights blended with polyethylmethylsiloxane (PEMS). The complete phase diagram was established through steady shear rheology, optical microscopy and light scattering. The UCST, interfacial tension and morphology of these blends are very sensitive to the molecular weight of the constituents. Partial miscibility was observed only when the Mw of PDMS was sufficiently low. The viscoelastic behaviour in the phase separated region can be modeled successfully using the Palierne model.

show abstract

Section: Phase Diagram Of Pdms/pems Blendssupporting

confidence: 84%

Section: Phase Diagram Of Pdms/pems Blendsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Interrelations between Rheology and Phase Behaviour in Partially Miscible Blends: The Case of Polydimethylsiloxane/Polyethylmethylsiloxane (PDMS/PEMS)

et al. 2002

View full text Add to dashboard Cite

show abstract

“…According to the normalization conditions, 1 WA(NA) dNA = WB(NB) dNB = 1 I (11) integration of the phase equilibrium relations (Eqs. (6) and (7)) results in:…”

Section: Eqs (3) and (4) Results Inmentioning

confidence: 99%

Phase separation of blends of polydisperse polymers: Comparison between experiment and theory for the system poly(dimethylsiloxane)/poly(ethylmethylsiloxane)

Enders

Stammer

Wolf

1996

Macro Chemistry & Physics

View full text Add to dashboard Cite

Cloud point curves were measured turbidimetrically for blends (upper critical solution temperatures; UCSTs) of poly(ethylmethylsi1oxane) (PEMS) and four different samples of poly(dimethylsi1oxane) (PDMS); the weight average molar masses in kg/mol are 31.2 for PEMS and 10.4, 15.5, 18.1 and 24.0 for PDMS; all components have polydispersity indices D (= MJM") within the range from 1.82 to 2.67. Corresponding calculations on the basis of the Flory-Huggins theory (three adjustable parameters) account for the polydispersity; molecular weight distributions are represented by the generalized SchulzFlory equation. Calculated cloud point curves agree very well with those measured, if individual sets of parameters are admitted for each of the different mixtures. Even for an identical set of parameters the maximum deviations remain moderate. Realistic model calculations concerning the influences of D on cloud points and on critical points were performed with this set of parameters.For the present (only slightly endothermal) system, the precipitation threshold increases from 318 to 558.6 K as D , , , is raised from 1.87 to 4.00, keeping the number average degree of polymerization constant.--

show abstract

“…In particular this is true for semicompatible polymer blends where the thermodynamic parameters strongly depend on the degrees of polymerisation of the components [1][2][3][4][5] . For polymers with similar monomer structure the mass-average and number-average molar masses M -w and M -n are often derived from calibration curves of a corresponding model system of such a series, where the absolute values of M -w and M -n have been determined very carefully.…”

Section: Introductionmentioning

confidence: 99%

Comparison of different methods for the determination of the molar mass and molar mass distribution of poly(ethylmethylsiloxane)

Götz

Maschke

Wagner

et al. 2000

Macromol. Chem. Phys.

View full text Add to dashboard Cite

The application of a poly(dimethylsiloxane) (PDMS) calibration curve for size exclusion chromatography (SEC) to poly(ethylmethylsiloxane) (PEMS) leads to molar masses, which are 15–40% higher than expected compared to measurements of the absolute molar mass values. As for the analysis of physical properties of PEMS, the exact knowledge of the molar mass is fundamental, therefore PEMS calibration curves for both SEC and viscometry were established. Eleven narrow distributed linear PEMS samples in the range between 4 000 and 110 000 g/mol were synthesised by anionic ring‐opening polymerisation of a cyclic monomer. The molar masses of the PEMS samples were determined by matrix assisted laser desorption ionisation time‐of‐flight mass spectrometry (MALDI‐TOF‐MS), light scattering, membrane osmometry, vapour pressure osmometry, and by viscometry. The polydispersities calculated from MALDI‐TOF‐MS spectra were lower compared to the SEC results. With the help of universal calibration, a SEC calibration curve for PEMS was established. Small angle neutron scattering (SANS) experiments on a 50%/50% protonated/deuterated PEMS blend match exactly the molar mass obtained from the PEMS calibration curve for SEC.

show abstract

Molecular weight dependence of the cloud-point curve of poly(dimethylsiloxane)/poly(methylethylsiloxane) mixtures

Cited by 15 publications

References 9 publications

Interrelations between Rheology and Phase Behaviour in Partially Miscible Blends: The Case of Polydimethylsiloxane/Polyethylmethylsiloxane (PDMS/PEMS)

Interrelations between Rheology and Phase Behaviour in Partially Miscible Blends: The Case of Polydimethylsiloxane/Polyethylmethylsiloxane (PDMS/PEMS)

Phase separation of blends of polydisperse polymers: Comparison between experiment and theory for the system poly(dimethylsiloxane)/poly(ethylmethylsiloxane)

Comparison of different methods for the determination of the molar mass and molar mass distribution of poly(ethylmethylsiloxane)

Contact Info

Product

Resources

About