Aging of the tensile properties. Glassy thiol-ene network polymers that contain secondary interchain interactions may exhibit a dramatic change of tensile properties over time -an "aging" effect. For example, triazole-based thiol-ene polymers became stiffer but brittle in less than one day. Although aging can be reversed by annealing at above Tg, they will again age, rendering them impractical as ductile materials. We noticed that our polyamide networks remained ductile even weeks after they were made. An entailed study of aging revealed surprising results. We tested at time intervals of 1 hour, 24 hours, 72 hours, and 168 hours after synthesis of the meta-phthalamide networks (f=2.25). The samples were stored on the bench open to air. To our surprise, at 24 hours, the polymer became noticeably brittle and the elongationat-break dropped from 140% to 21%. Interestingly, the polymer gradually restored its ductility. At 72 hours, the elongation-at-break increased to 44%; at 168 hours, the tensile properties were restored to be indifferent with the 1-hour sample (Figure ). We are baffled by the autonomous reverse of aging.