The influence of molecular variables on fatigue resistance in stress cracking environments

The increasing economic importance of the polymer industry is responsible for a growing interest in the prediction of the lifetime of polymers. Although the influence of molecular parameters on the fatigue resistance in polymers has been intensively addressed, little work has been devoted to the same topic in stress cracking environments. Because of the complexity of the topic, we have studied different cases of mechanical loading, short-time, long-time, static, and dynamic in a stress cracking environment with special attention paid to fatigue, where the polymer is dynamically loaded over a long period. Fatigue crack propagation experiments can be employed as a fast and effective method for determining the long-term mechanical properties of polymers. We have particularly studied the effect of molecular weight, chain regularity, medium parameters, and processing and treatments on fatigue resistance. Special attention is also paid to the existing environmetal stress cracking prevention methods. We present an overview of the existing work and also our personal contribution to the field.