Abstract: A novel method for grafting polymers to polytetrafluoroethylene (PTFE) and composites grafted according to this method are described. PTFE at a surface of a substrate is reduced to polyacetylene (PA) and then doped with a suitable dopant. The doped PA/PTFE substrate is then contacted with a polymerizable monomer precursor capable of polymerizing with doped PA, to form the polymer of said precursor chemically bonded to the surface of the PA/PTFE substrate. A grafted composite with layers of varying thickness may be formed by further contacting the substrate bonded to polymer with preformed polymer of a similar cohesive energy density.

Abstract: A device for monitoring environmental exposure includes an element whose electrical properties change, in a predetermined way, in response to the environmental exposure. The element may be part of a tuned circuit or of a shield for a tuned circuit. In either case, when the tuned circuit is interrogated, preferably by an r.f. or microwave signal, it emits a signal whose intensity depends on the electrical properties of the element. Thus, an incremental environmental exposure can be measured by a change in the signal intensity. The device is particularly useful for monitoring the condition of perishable materials, because it can be located with the perishable inside a packaging material during both storage and interrogation.

Abstract: Polymeric sulfur nitride (SN).sub.x is utilized as the conducting explosive aterial in electric initiators.