Viscoelasticity of polydimethylsiloxane at the sol-gel threshold: structural effects

• Autorzy: Gasparoux, J. , Tixier, T. , Tordjeman, P.
• Konferencja: Third International Conference on Engineering Rheology, ICER 2005
• Języki publikacji: EN

Abstrakty

EN

Six model polydimethylsiloxane (PDMS) networks were obtained by hydrosilation of a difunctional vinyl-terminated PDMS prepolymer with a SiH containing crosslinker. Viscoelastic experiments were performed in order to study the influence of molecular parameters on the dynamic properties around the sol-gel threshold. Critical parameters were determined close to and above the sol-gel threshold. Our results show, in agreement with those of Lusignan et al. (1999), that the gel growth mechanism is function of the ratio N/Ne, where N and Ne are the numbers of Kuhn monomers between branch points and between entanglements, respectively. By considering the literature results, three universality classes are pointed out for polymer gelation: the sol-gel transition is governed by critical percolation for N/Ne < 1, by Diffusion Limited Cluster Aggregation for 1 < N/Ne < 2, and by mean field theory for N/Ne > 2.

Słowa kluczowe

PL

lepkosprężystość; wymiar fraktalny; efekt strukturalny

EN

sol-gel transition; fractal dimension; Rouse dynamics

• Czasopismo: International Journal of Applied Mechanics and Engineering
• Rocznik: 2005
• Tom: Vol. 10, no spec
• Strony: 315-322
• Opis fizyczny: Bibliogr. 21 poz., tab., wykr.

Twórcy

autor

Gasparoux, J.

• Laboratoire d'Analyse des Interfaces et de Nanophysique - UMR-5011 Université Montpellier 2 cc 082 - Place E. Bataillon 34095 Montpellier Cedex 5 - FRANCE

autor

Tixier, T.

• Laboratoire d'Analyse des Interfaces et de Nanophysique - UMR-5011 Université Montpellier 2 cc 082 - Place E. Bataillon 34095 Montpellier Cedex 5 - FRANCE

autor

Tordjeman, P.

• Laboratoire d'Analyse des Interfaces et de Nanophysique - UMR-5011 Université Montpellier 2 cc 082 - Place E. Bataillon 34095 Montpellier Cedex 5 - FRANCE,

Bibliografia

• [1] Adam M. and Lairez D. (1996): Sol-gel transition, In: Physical properties of polymeric gels (Cohen Addad J.P., fU,). New York.
• [2] Adam M., Lairez D., Karpasas M. and Gottlieb M. (1997): Static and dynamie properties of crossdbs poly(dimethylsiloxane) pregel clusters. - Macromolecules, vol.30, pp.5920-5929.
• [3] Chambon F. and Winter H. (1987): Linear viscoelasticity at the gel point of a crosslinking PDMS with imbalamed stoichiometry. - J. Rheol., vol.31, pp.683-697.
• [4] Daoud M. (1979): Vulcanization and critical exponents. - J. Phys. Lett., vol.40, No.9, pp.L201-L205.
• [5] Daoud M. and Lapp A. (1990): Branchedpolymers and gels. - J. Phys. Condens. Matter, vol.2, pp.4021-4050.
• [6] de Gennes P. (1979): Scaling Concepts in Polymer Physics. - Ithaca: Cornell University Press.
• [7] Flory P.J. (1941): Molecular size distribution in three-dimensional polymers. I. Gelation. - J. Am. Chem. Soc., V0l pp.3083-3090.
• [8] Flory P.J. (1953): Principles of Polymer Chemistry. - Ithaca: Cornell University Press.
• [9] Larson R. (1999): The structure and rheology ofcomplex fluids. - Oxford: Oxford University Press.
• [10] Leibler L. and Schosseler F. (1985): Gelation of polymer Solutions: an experimental verification ofthe scaling behtwhn of the size distribution function. - Phys. Rev. Lett., vol.55, pp. 1110-1113.
• [11] Lusignan C.P., Mourey T.H., Wilson J.C. and Colby R.H. (1999): Viscoelasticity of randomly branched polymers In the vulcanization class. - Phys. Rev. E, vol.60, pp.5657-5669.
• [12] Muthukumar M. (1985): Dynamics of polymeric fractals. - J. Chem. Phys., vol.83, pp.3161-3168.
• [13] Muthukumar M. (1989): Screening effect on visco. Near the gel point. - Macromolecules, vol.22, pp.4656-4658.
• [14] Nicolai T., Randrianantoandro H., Prochazka F. and Durand D. (1997): Viscoelastic relcucation of polyurethane ot different stages of the gelformation 2- Sol-gel transition dynamics. - Macromolecules, vol.30, pp.5897-5904,
• [15] Scanlan J.C. and Winter H. (1991): Composition dependence of the viscoelasticity of poly(dimehtylsiloxane) at the gel point. - Macromolecules, vol.24, pp.47-54.
• [16] Schosseler F., Benoit H., Grubisic-Gallot Z., Strazielle C. and Leibler L. (1989): Macromolecules, vol.22, pp.400-410.
• [17] Stauffer D. and Aharony A. (1994): Percolation Theory. - London.
• [18] Stauffer D., Coniglio A. and Adam M. (1982): Gelation and critical phenomena. - Adv. Polym. Sci., vol.44, pp. 103-164.
• [19] Stockmayer W.H. (1943): Theory of molecular size distribution and gel formation in branched-chain polymers, J. Chem. Phys., vol.ll, pp.45-55.
• [20] Stockmayer W.H. (1944): J. Chem. Phys., vol.l2, pp.125-131.
• [21] Williams E., Wengrovius J., Valkenburgh V. and Smith J. (1991): Structural analysis of poly(tetramethyl-p siphenylenesiloxane)-poly(dimethylsiloxane) copolymers by29Si NMR. - Macromolecules, vol.24, pp. 1445-1448.