Dynamic structure factor of crosslinked polymer blends

Benhamou, M.; Chahid, M.

doi:10.1016/j.physa.2006.05.015

Cited by 4 publications

(1 citation statement)

References 24 publications

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“…The structure-property relationships that govern the crosslinked polymer networks are a subject of intense interest from both academic and practical point of view. Subtle changes in reaction conditions and composition can lead to substantial differences in network architecture and topology, resulting in prominent variations in the macroscopic properties [1][2][3][4][5] .…”

Section: Introductionmentioning

confidence: 99%

Investigation on Dynamic Mechanical Properties of Crosslinked Poly(styrene-co-divinylbenzene) Bulk Copolymers: Effect of Divinylbenzene Content

Zhu

Qing

et al. 2012

Polymers and Polymer Composites

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The crosslinked poly(styrene-co-divinylbenzene) (CL-p(St-DVB)) bulk copolymers were fabricated by free-radical bulk crosslinking copolymerization (FCC) with styrene as monomer and divinylbenzene (DVB) as crosslinker. The viscoelastic properties of the crosslinked copolymers were investigated by dynamic mechanical thermal analysis (DMTA) as a function of temperature and frequency. The Arrhenius relationship was employed to calculate the activation energy of the α-relaxation transition for the specimens. The results revealed that the storage modulus (E′) of the copolymer networks enhanced with the rising DVB content. The loss tangent (tanδ) peaks were lower and broader. The dynamic mechanical responses of the CL-p(St-DVB) networks were also strongly depended on the test frequency.

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Section: Introductionmentioning

confidence: 99%

Investigation on Dynamic Mechanical Properties of Crosslinked Poly(styrene-co-divinylbenzene) Bulk Copolymers: Effect of Divinylbenzene Content

Zhu

Qing

et al. 2012

Polymers and Polymer Composites

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Field-theoretical Renormalization-Group approach to critical dynamics of crosslinked polymer blends

Benhamou

Chahid²

2008

Eur. Phys. J. E

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We consider a crosslinked polymer blend that may undergo a microphase separation. When the temperature is changed from an initial value towards a final one very close to the spinodal point, the mixture is out equilibrium. The aim is the study of dynamics at a given time t, before the system reaches its final equilibrium state. The dynamics is investigated through the structure factor, S(q, t), which is a function of the wave vector q, temperature T, time t, and reticulation dose D. To determine the phase behavior of this dynamic structure factor, we start from a generalized Langevin equation (model C) solved by the time composition fluctuation. Beside the standard de Gennes Hamiltonian, this equation incorporates a Gaussian local noise, zeta. First, by averaging over zeta, we get an effective Hamiltonian. Second, we renormalize this dynamic field theory and write a Renormalization-Group equation for the dynamic structure factor. Third, solving this equation yields the behavior of S(q, t), in space of relevant parameters. As result, S(q, t) depends on three kinds of lengths, which are the wavelength q(-1), a time length scale R(t) approximately t(1/z), and the mesh size xi*. The scale R(t) is interpreted as the size of growing microdomains at time t. When R(t) becomes of the order of xi*, the dynamics is stopped. The final time, t*, then scales as t* approximately xi*z, with the dynamic exponent z = 6-eta. Here, eta is the usual Ising critical exponent. Since the final size of microdomains xi* is very small (few nanometers), the dynamics is of short time. Finally, all these results we obtained from renormalization theory are compared to those we stated in some recent work using a scaling argument.

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Theory of microphase separation in charged crosslinked polymer blends with arbitrary charge distribution

Boussaid

Benhamou²,

Fazni³

2009

Eur. Phys. J. E

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In this paper, we are interested in the phase behavior and scattering properties of charged crosslinked polymer blends in solution. The system undergoes a microphase separation, below some critical temperature. To study such a transition, use is made of the standard de Gennes theory based on an analogy with a dielectric medium. This analogy is extended to include the effects of the initial composition fluctuations in order to improve its agreement with experimental data in the small wave vector range. The excluded-volume interactions are explicitly introduced through the blob model. The charge effects on the phase behavior are examined, for any charge distribution of polyions and for any salt concentration. This completes a previous study which was concerned with the situation where only one species is charged. The early kinetics of microphase separation is discussed, and the charges contribution to the growth rate is also evaluated.

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Dynamic structure factor of crosslinked polymer blends

Cited by 4 publications

References 24 publications

Investigation on Dynamic Mechanical Properties of Crosslinked Poly(styrene-co-divinylbenzene) Bulk Copolymers: Effect of Divinylbenzene Content

Investigation on Dynamic Mechanical Properties of Crosslinked Poly(styrene-co-divinylbenzene) Bulk Copolymers: Effect of Divinylbenzene Content

Field-theoretical Renormalization-Group approach to critical dynamics of crosslinked polymer blends

Theory of microphase separation in charged crosslinked polymer blends with arbitrary charge distribution

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