Elastomers are prepared from a reaction mixture that contains a polyene compound, an epoxy resin, a thiol curing agent and a basic catalyst. The polyene compound has an average of at least two groups containing aliphatic carbon-carbon double bonds capable of reaction with a thiol group. At least one of said aliphatic carbon-carbon double bonds is separated from each other said aliphatic carbon-carbon double bond by an aliphatic spacer group having a weight of at least 500 atomic mass units. These elastomers are typically phase-separated materials having good elongation and tensile properties.
