Mingshi SONG
,
Wen ZHOU
,
Guixian HU
,
Lijiang HU
材料科学技术（英文）
A double-network model is established, which consists of the segments, E and A-constituent chains, the polymeric chains entangled with other ones by multi-entanglement and polymeric chains connected to a great number of destructible particles by multi-adsorption, based on which the E and A-constituent chains can be recreated and released dynamically. The distribution function of the end-to-end vector, the statistical distribution function of conformation for two kinds of chains in the multi-entanglement and multi-adsorption states and their number of polymeric chains are calculated by the combination of statistical mechanics and kinetics. Then the viscoelastic free energies of deformation for two kinds of the networks and suspensions are calculated by Boltzmann's statistical theory. Also, elastic modulus and memory function for two kinds of the network and suspensions are derived. Consequently, a new molecular theory of the non-linear viscoelasticity for polymeric suspensions is proposed, and the constitutive equation and material function with yielding and thinning for the polymeric suspensions in different flow fields are derived from this theory.
关键词:
Mingshi SONG
,
Wen ZHOU
,
Guixian HU
,
Lijiang HU
材料科学技术（英文）
The memory function and elastic modulus were introduced into the O-W-F type of constitutive equations with the Cauchy-Green and Finger tensors for simple fluid, and then the concrete constitutive equation and material function for polymeric suspensions in the different flow fields were formulated: 1) Viscosity and first normal-stress difference coefficient in the shear flow field; 2) Tensile viscosity at the uni-axial elongation flow field; and 3) Dynamic viscosity and modulus in the dynamic field. Then the dependence of the material function on the deformation rate and weight fraction of fillers was discussed, and the shear flow curves with four characteristic regions ( I-low shear rate plateau region, II-apparent yielding region, III-intermediate rate plateau region, and IV-shear thinning region.) were explained theoretically. Finally, it was verified by a number of experimental values for the rheological suspensions and the viscoelastic and mechanical behaviors can be predicted by the molecular theory of non-linear viscoelasticity for polymeric suspensions.
关键词:
