Thermoplastic-Thermoset Engineering Materials

This group of engineering plastics shows some of the typical characteristics of both the thermoplastics and the thermosets. At normal use temperatures, they exhibit a cross-linked network structure relating them to the thermosets yet they can be easily processed by standard or slightly modified thermoplastic forming methods. The network structure of the thermoplastic-thermosets differs in its nature from typical thermosets as shown by three examples (1) the ionomers, (2) the styrene-butadiene elastomers, and (3) the polyurethanes. Physical and mechanical properties of the three groups of thermoplastic-thermosets are discussed pointing out their special advantages as compared with competitive materials. Although the thermoplastic-thermosets are slightly more expensive than the largest volume thermoplastics or thermosets on a per pound basis, it is shown that the thermoplastic-thermosets are often favored because of their unique physical properties combined with cost savings in processing.