Indentation into polymeric foams

Characterization of polymeric foams

Negative Poisson's Ratio Polymeric and Metallic Foams

Foam materials based on metal and several polymers were transformed so that their cellular architectures became re-entrant, ie. with inwardly protruding cell ribs. Foams with re-entrant structures exhibited negative Poisson's ratios as well as greater resilience than conventional foams. Foams with negative Poisson's ratios were prepared using different techniques and materials and their mechani...

Mechanical properties of CNT reinforced nano-cellular polymeric nanocomposite foams

Mechanics of CNT-reinforced nano-cellular PMMA nanocomposites are investigated using coarse-grained molecular dynamics simulations. Firstly, static uniaxial stretching of bulk PMMA polymer is simulated and the results are compared with literature. Then, nano-cellular foams with different relative densities are constructed and subjected to static uniaxial stretching and obtained stress-strain cu...

Covalent incorporation of the surfactant into high internal phase emulsion templated polymeric foams.

High internal phase emulsions of water in cyclooctene stabilised by sorbitan monooleate (Span 80) were cured by ring-opening metathesis polymerisation to release fully open macroporous polymer foams wherein the surfactant was covalently incorporated into the poly(cyclooctene) strands via chain transfer reactions.

Failure of brittle layers on polymeric substrates from Vickers indentation

A study is made of median crack evolution in brittle coatings subjected to sharp contacts. A model bilayer system consisting of a glass plate bonded to a polycarbonate base, with a Vickers pyramid as indenter, is used to demonstrate the evolution in situ. The cracks undergo a phase of stable downward growth with increasing load. Beyond the coating mid-plane, flexural stresses (coupled with the ...