Stress-Optical Coefficient of Poly(ethylene oxide) and Poly(propylene oxide) Networks. Measurements

Ishikawa, Toshihide

doi:10.1295/polymj.5.227

Cited by 6 publications

(1 citation statement)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have not found a reported C value of linear PEO aqueous solution in the literature yet. C of the PEO network swollen in water 25 and of PEO melts 26 were found to be close to that of linear PEO aqueous solution measured in this study. SOR of dispersions containing nanoparticles has a weak dependence upon γ ˘when γ ˘is small and decreases at high γ ˘.…”

Section: Resultssupporting

confidence: 84%

Optical Polarimetry and Mechanical Rheometry of Poly(ethylene oxide)−Silica Dispersions

Zhang

Archer

2004

Macromolecules

View full text Add to dashboard Cite

Mesoscale structural dynamics and rheology of semidilute aqueous dispersions of poly(ethylene oxide) (PEO) containing nanosized silica particles are investigated using mechanical rheometry, optical polarimetry, and dynamic light scattering measurements. The average diameter of silica particles in the dispersions is chosen to be much smaller than the polymer coil diameter to study the effect of polymer−particle interactions on solution properties. For particle volume fractions as low as 0.2%, a nearly 2-fold increase in the solution viscosity and optical anisotropy is observed. At a particle volume fraction of 2% the viscosity and optical birefringence are an order of magnitude larger than in the neat polymer solutions. At low shear rates, polymer−nanoparticle dispersions manifest larger stress−optical ratios than the neat polymer solutions; they violate the stress−optical rule at high shear rates. Nanoparticles are also found to dramatically slow down stress relaxation of the solutions and to shift the onset of shear thinning behavior to lower shear rates. These findings are discussed in terms of the polymer bridging effect, which produces soft colloidal structures that are larger in size than either the polymer or primary particles. Slower dynamics of these secondary structures and flow-induced changes of their shape are argued to produce other properties observed.

show abstract

Section: Resultssupporting

confidence: 84%

Optical Polarimetry and Mechanical Rheometry of Poly(ethylene oxide)−Silica Dispersions

Zhang

Archer

2004

Macromolecules

View full text Add to dashboard Cite

show abstract

Strain birefringence in ethylene‐propylene copolymers

Llorente

Mark

1981

J. Polym. Sci. Polym. Phys. Ed.

View full text Add to dashboard Cite

A series of polymeric networks were prepared by the γ‐radiation crosslinking of two ethylene‐propylene copolymers containing 62 and 69 mol % ethylene units. The elastomeric materials thus obtained were studied in elongation, both swollen and unswollen, over the temperature range −30 to 95°C. The experiments involved measurements of both the elastic force and birefringence, using primarily changes in temperature at constant length (rather than changes in length at constant temperature). There is evidence for crystallization in these networks, as manifested by marked decreases in force and increases in birefringence at relatively low elongations and at temperatures as high as 70°C. As expected, the birefringence and related quantities were found to be more sensitive to crystallization than the force, with the stress‐optical coefficient showing the greatest sensitivity. The results obtained in the elongation‐temperature regions presumably free from effects of network crystallization were used to calculate values of the temperature coefficient of the unperturbed dimensions of the chains, and values of the optical‐configuration parameter. Both are widely used to characterize (spatial) configurations of chain molecules. Values of the former quantity are in very good agreement with those predicted some years ago using a rotational isomeric state model for ethylene‐propylene chains of various chemical and stereochemical compositions. The extension of these theoretical calculations to include the stress‐optical coefficient should provide further information on crystallization in ethylene‐propylene elastomers and the configurational characteristics of these copolymeric chains.

show abstract

Stress‐optical behavior of polydimethylsilmethylene [Si(CH₃)₂CH₂], a hydrocarbon analog of polydimethylsiloxane, and a silicon analog of polyisobutylene

Llorente

Mark

Sáiz

1983

J. Polym. Sci. Polym. Phys. Ed.

View full text Add to dashboard Cite

Elastomeric networks were prepared from polydimethylsilmethylene (PDMSM) [Si(CH3)2CH2], a polymer closely related to polydimethylsiloxane (PDMSO) [Si(CH3)2O] and polyisobutylene (PIB) [C(CH3)2CH2]. The birefringence of PDMSM in elongation was found to be qualitatively similar to that of PDMSO, in that there was no evidence for strain‐induced crystallization. However, the values of the optical‐configuration parameter Δa were considerably larger, and both Δa and its temperature coefficient are essentially the same as those of PIB. Swelling the PDMSM networks generally decreased Δa; the largest decreases, obtained as expected with the most nearly symmetrical diluent, were also approximately the same as those observed for PIB. Use of cyclic PDMSO pentamer as diluent in a PDMSM network was found to increase the birefringence, presumably because of orientational effects. Various network‐diluent combinations involving the significantly anisotropic PDMSM and the more nearly isotropic PDMSO should be extremely useful for elucidating the nature of these intermolecular correlations. Results obtained from rotational isomeric state theory considerably underestimate both Δa and its temperature coefficient for PDMSM, as they do for PIB. Although the origin of the discrepancy is not necessarily the same for both polymers, the results on PDMSM suggest that the discrepancy for PIB is not due to the severe steric congestion known to be present in this polymer.

show abstract

Stress-Optical Coefficient of Poly(ethylene oxide) and Poly(propylene oxide) Networks. Measurements

Cited by 6 publications

References 12 publications

Optical Polarimetry and Mechanical Rheometry of Poly(ethylene oxide)−Silica Dispersions

Optical Polarimetry and Mechanical Rheometry of Poly(ethylene oxide)−Silica Dispersions

Strain birefringence in ethylene‐propylene copolymers

Stress‐optical behavior of polydimethylsilmethylene [Si(CH₃)₂CH₂], a hydrocarbon analog of polydimethylsiloxane, and a silicon analog of polyisobutylene

Contact Info

Product

Resources

About

Stress-Optical Coefficient of Poly(ethylene oxide) and Poly(propylene oxide) Networks. Measurements

Cited by 6 publications

References 12 publications

Optical Polarimetry and Mechanical Rheometry of Poly(ethylene oxide)−Silica Dispersions

Optical Polarimetry and Mechanical Rheometry of Poly(ethylene oxide)−Silica Dispersions

Strain birefringence in ethylene‐propylene copolymers

Stress‐optical behavior of polydimethylsilmethylene [Si(CH3)2CH2], a hydrocarbon analog of polydimethylsiloxane, and a silicon analog of polyisobutylene

Contact Info

Product

Resources

About

Stress‐optical behavior of polydimethylsilmethylene [Si(CH₃)₂CH₂], a hydrocarbon analog of polydimethylsiloxane, and a silicon analog of polyisobutylene