Microcracks network formation

In Ref [69], the supposition was made that p change can be conditioned to microcracks network formation in specimen that results to p reduction at large (0.43 and 0.52), which are close to the limiting ones. The p relative change (Ap) can be estimated according to the equation... 

The structural capsules start to be formed in films subjected to deformation in liquids until some tension threshold. Microcracks and microvoids appear and are filled with the inhibiting liquid under tensile stresses exceeding the polymer flow limit. Capillary channels connecting these voids with the process liquid and with each other start to merge or open in the course of structural transformations but do not disappear fully. The liquid may move over the network of the formed channels beyond the polymer matrix limits or concentrate in some voids able under certain conditions to enlarge the manifold. Thermal treatment of the deformed film intensifies the relaxation processes in the polymer matrix, the film shrinks in the tension direction and the capillaries between voids link up densely, thus insulating liquid particles from each other. If the film is treated in the extended state, a more complex mechanism of microcapsule formation is realized [4]. Cl liberation from microcapsules is related to their ability to break spontaneously under residual... 

Microcrack formation and crack propagatiOTi are a common cause of material failure. To overcome this problem, supramolecular polymer networks have been developed that can self-heal on the basis of the dynamic nature of their reversible cross-links [268]. The healing can either occur in an autonomous fashion or upmi exposure to an external stimulus such as heat, light, pressure, or mechanical stress. 

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