Thermoplastic unsaturated elastomer Thermoset polymers

This section will cover polymer blends containing thermosetting polymers as at least one of the constituents. Crosslinked elastomers will not be discussed in this section, as they are covered in Section 4.2. Specific thermosetting polymers include epoxies, phenolics, unsaturated polyesters, bismaleimides, vinyl esters, cyanate esters and polyurethanes, which are the major commercial thermoset polymers. Preparation of thermoset polymer blends comprised of thermoset/thermoset or thermoset/thermoplastic combinations will require in-situ polymerization as melt processing of thermosetting polymers is not possible. The in-situ polymerization procedure can include ... 

Hybrid versions of silicone-thermoplastic semi-IPNs have been developed (19). A hybrid interpenetrating network is one in which the cross-linked network is formed by the reaction of two polymers with structurally distinct backbones. Hydride-functionalized siloxanes can be reacted with organic polymers with pendant unsaturated groups such as polybutadienes (5) in the presence of platinum catalysts. Compared with the polysiloxane semi-IPNs discussed earlier, the hydride IPNs tend to maintain mechanical and morphologically derived properties, whereas properties associated with siloxanes are diminished. The probable importance of this technology is in cost-effective ways to induce thermoset characteristics in thermoplastic elastomers. 

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