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The adhesion between a rigid flat-end cylindrical punch and an incompressible elastic film deposited on a rigid substrate is studied. The contact interfaces between the punch and the elastic film and between the elastic film and the rigid substrate are either free to slide over one another (frictionless or slip boundary condition) or locked together (perfectly bonded or stick boundary condition). The solutions for these cases are the upper and lower bounds for the real situation in which the contact interfaces are neither frictionless nor perfectly bonded. By use of a thermodynamic method with the assumption that the detachment starts at the periphery so that the contact area remains circular all the time, the pull-off force to separate the rigid cylindrical punch from the elastic layer is obtained. The results show that the pull-off force strongly depends on the contact conditions at the interfaces.

The effect of cold work on the transport of liquid methanol in crosslinked PMMA disks has been determined at temperatures from 35–56°C. Deformed samples absorb at fast rates with kinetics that approach those of Fickian diffusion. Undeformed samples sorb at lower rates and the kinetics tend toward those of Case II transport. Shape recovery accompanied swelling in deformed samples. Samples saturated with methanol were desorbed in cyclohexanol. Resorption of desorbed samples showed fast rates for both deformed and undeformed samples and matched those of the absorption cycle in deformed samples. An analogy is made between the microstructure due to cold work and due to swelling.

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Some recent observations on shear bands in polymers are reviewed. These include intrinsic properties such as the mechanism of formation, the intersection of shear bands, the rate of propagation with and without obstacles, recovery of shear strain by annealing, and the stored energy in shear bands. Mechanical responses include the shear yielding criteria, reverse shear behavior and the Bauschinger effect, and the fracture of and at shear bands. Environmental effects include methanol transport in shear bands and in deformed poly(methy1 methacrylate) in the region of mixed Fickian and case I1 behavior and methanol crazing of a shear banded material.

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