Abstract: A new kinetic theory of tensile strength for polymer networks has been proposed. It is based on the Eyring chemical activation rate theory and the molecular theory of rubber elasticity at large deformations. The coefficient of overstress of a polymer chain is derived by combining the deformation behavior, stress concentration of a polymer chain and the chain orientation as a united event of polymer failure. A kinetic equation for bond rupture of over-stressed chain is established by taking the coefficient of overstress as a variable. After integration and simplification a new equation of state for ultimate fracture is obtained. It is successful in reating the ultimate strength and extensibility to the parameters of structure, the temperature and the extension rate. The failures of four different polymer networks were studied by uniaxial extension method. These experimental data of ultimate properties were treated with the proposed theory. The results show that the proposed theory can predict the failure behavior of polymer networks and provide a theoretical foundation for the construction of failure envelop.

摘要： 本文提出了一种等速拉伸下聚合物网极限断裂强度的动力学理论.从化学活化反应速度理论和橡皮大形变弹性分子理论出发,建立了以链的应力集中系数为变量的断链动力学方程.得到了等速拉伸下聚合物网的极限断裂状态方程,成功地把极限断裂性能同聚合物网的结构和测试条件联系起来.并用4种聚合物网的极限断裂性能数据验证了该理论,得到了理论同实验很好地符合,亦为建立聚合物的破裂包络线提供了理论基础.