Aspects of Physical Ageing and Network Formation in Glassy Thermosets

摘要

Aspects of network formation and the physical properties of stoichiometric amine-cured epoxy resins are investigated. The state of network formation is systematically controlled by using isothermal cure conditions and a linear temperature ramp condition. Affine deformation in compression at a constant true strain rate is used to measure the true stress-strain response from small strains to large strains. Beginning with the low-strain responses and continuing through yield, partially cured samples demonstrate an inherent physical ageing response that diminishes as the networks approach full conversion. The post-yield properties are characterized by a strong dependence on network connectivity with little influence of the curing method.