### Abstract

The temperature dependence of elastic moduli and the equilibrium concentration of swollen poly(vinyl acetate) gels were studied. For gels swollen to equilibrium in a good diluent (toluene), the power law exponent of the elastic moduli, m, was found to be independent of the temperature and to be close to the value predicted by scaling theory. Poly(vinyl acetate) gels equilibrated with isopropyl alcohol in the vicinity of θ temperature were studied. In the crossover regimes (below and above the θ temperature), the apparent power law exponent of the elastic moduli varied between the values of 2.31 and 13.3. At the θ temperature m = 3.04 was obtained. Supposing that the third power of the expansion factor of network chains can be expressed as the ratio of the equilibrium concentration of the gel at θ temperature (φ_{e,θ}) to the actual concentration (φ_{e}) either below or above θ, it was verified that φ_{e,θ}/φ_{e} is the only function of τN^{1/2} (where τ and N are the reduced temperature and the degree of polymerization, respectively). Analysis of the experimental data on the basis of thermal blob theory indicated a satisfactory agreement at N/N_{τ} > 10; however, at smaller N/N_{τ} values considerable deviation occurred (N_{τ} is the temperature-dependent cutoff distance which separates the scales of Gaussian and non-Gaussian behavior within the same chain).

Original language | English |
---|---|

Pages (from-to) | 2805-2811 |

Number of pages | 7 |

Journal | Macromolecules |

Volume | 17 |

Issue number | 12 |

Publication status | Published - 1984 |

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### ASJC Scopus subject areas

- Materials Chemistry

### Cite this

*Macromolecules*,

*17*(12), 2805-2811.

**Studies on mechanical and swelling behavior of polymer networks on the basis of the scaling concept. 5. Crossover effects above and below the θ temperature.** / Zrínyi, M.; Horkay, Ferenc.

Research output: Contribution to journal › Article

*Macromolecules*, vol. 17, no. 12, pp. 2805-2811.

}

TY - JOUR

T1 - Studies on mechanical and swelling behavior of polymer networks on the basis of the scaling concept. 5. Crossover effects above and below the θ temperature

AU - Zrínyi, M.

AU - Horkay, Ferenc

PY - 1984

Y1 - 1984

N2 - The temperature dependence of elastic moduli and the equilibrium concentration of swollen poly(vinyl acetate) gels were studied. For gels swollen to equilibrium in a good diluent (toluene), the power law exponent of the elastic moduli, m, was found to be independent of the temperature and to be close to the value predicted by scaling theory. Poly(vinyl acetate) gels equilibrated with isopropyl alcohol in the vicinity of θ temperature were studied. In the crossover regimes (below and above the θ temperature), the apparent power law exponent of the elastic moduli varied between the values of 2.31 and 13.3. At the θ temperature m = 3.04 was obtained. Supposing that the third power of the expansion factor of network chains can be expressed as the ratio of the equilibrium concentration of the gel at θ temperature (φe,θ) to the actual concentration (φe) either below or above θ, it was verified that φe,θ/φe is the only function of τN1/2 (where τ and N are the reduced temperature and the degree of polymerization, respectively). Analysis of the experimental data on the basis of thermal blob theory indicated a satisfactory agreement at N/Nτ > 10; however, at smaller N/Nτ values considerable deviation occurred (Nτ is the temperature-dependent cutoff distance which separates the scales of Gaussian and non-Gaussian behavior within the same chain).

AB - The temperature dependence of elastic moduli and the equilibrium concentration of swollen poly(vinyl acetate) gels were studied. For gels swollen to equilibrium in a good diluent (toluene), the power law exponent of the elastic moduli, m, was found to be independent of the temperature and to be close to the value predicted by scaling theory. Poly(vinyl acetate) gels equilibrated with isopropyl alcohol in the vicinity of θ temperature were studied. In the crossover regimes (below and above the θ temperature), the apparent power law exponent of the elastic moduli varied between the values of 2.31 and 13.3. At the θ temperature m = 3.04 was obtained. Supposing that the third power of the expansion factor of network chains can be expressed as the ratio of the equilibrium concentration of the gel at θ temperature (φe,θ) to the actual concentration (φe) either below or above θ, it was verified that φe,θ/φe is the only function of τN1/2 (where τ and N are the reduced temperature and the degree of polymerization, respectively). Analysis of the experimental data on the basis of thermal blob theory indicated a satisfactory agreement at N/Nτ > 10; however, at smaller N/Nτ values considerable deviation occurred (Nτ is the temperature-dependent cutoff distance which separates the scales of Gaussian and non-Gaussian behavior within the same chain).

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UR - http://www.scopus.com/inward/citedby.url?scp=33645814465&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:33645814465

VL - 17

SP - 2805

EP - 2811

JO - Macromolecules

JF - Macromolecules

SN - 0024-9297

IS - 12

ER -