**11. Elastomer polymer blends**

Elastomers are often used in blends with other polymers. When the elastomer is the minor component it will constitute a disperse phase. A disperse phase elastomer will be a toughening additive for the matrix phase that could be a thermoplastic or a thermoset polymer.

When the elastomer is the major component it will be a matrix phase and the overall blend will be an elastomer. The disperse phase blended polymer will contribute to physical crosslinks that will prevent creep and assist with reversibility of elastomer deformation.
