Structure-property relationships as a tool for the formulation of high-performance epoxy-amine networks

摘要

Inspection of the structure-property relationships already established for epoxy-amine networks allows the design of some novel formulations leading to high-performance materials. This was achieved by choosing an additive, miscible in the mixture of monomers, but which gives rise to phase nanoseparation along the network construction. As a result, small domains, consisting of additive molecules trapping some network chains, are dispersed in the polymer matrix which also contains residual additive molecules. The main effects of this special morphology on the properties of the networks are the depression of the main relaxation temperature, T_α, of the matrix and the appearance of some damping (so-called μ relaxation) in the temperature range intermediate between the secondary relaxation and T_α. The networks prepared in this way exhibit a lower water uptake at equilibrium, and present higher modulus and higher toughness around room temperature than conventional systems without additive. Friction experiments showed that the increase in toughness drastically delays crack propagation within the contact and, in turn, can improve the wear resistance of the material.