Department of Technical Physics, Technical University of Radom, Radom 26-600, Poland.
J Chem Phys. 2010 Sep 21;133(11):114901. doi: 10.1063/1.3479841.
Elasticity of the polymer network, with nematic interactions between segments of all the system chains, is considered. The Maier and Saupe molecular mean-field is used for description of nematic interactions. Calculations are performed for non-Gaussian network containing chains of finite contour length. The network topological structure is taken into consideration via the system contraction coefficient. Values of thermodynamic parameters, necessary for the existence of the isotropic-nematic equilibrium, are calculated. The system free energy (Helmholtz function) is calculated for any direction of external elongation of the network. A relation between the deformation force and elongation ratio is obtained. The network can have isotropic as well as anisotropic elastic properties. It depends on the system internal orientations and chain lengths. For the network in isotropic phase, defined with respect to orientation of segments, elastic constants have the same values in any direction. It is independent of whether the chain length is finite or infinite. In the nematic phase, the network elastic constants have the same values for chains with infinite length, while they are many in various directions for finite length of chains. The problem of the nematic axis rotation under the system external deformation is considered.
考虑了聚合物网络的弹性，其中所有系统链段之间存在向列相互作用。Maier 和 Saupe 分子平均场用于描述向列相互作用。针对具有有限轮廓长度的链的非高斯网络进行了计算。通过系统收缩系数考虑了网络拓扑结构。计算了存在各向同性-向列平衡所需的热力学参数的值。为网络的任何外部伸长方向计算了系统自由能（亥姆霍兹函数）。得到了变形力与伸长比之间的关系。网络可以具有各向同性和各向异性弹性性质。这取决于系统的内部取向和链长。对于相对于段取向定义的各向同性相中的网络，弹性常数在任何方向上具有相同的值。它与链长是否有限或无限无关。在向列相中，对于具有无限长度的链，网络弹性常数具有相同的值，而对于有限长度的链，它们在各个方向上具有许多值。考虑了系统外部变形下向列轴旋转的问题。
