4. Polymer properties

The characteristics of PMR polyimides are difficult to pin down, since the vast majority are manufactured as matrices for composites and not as polymers on their own. Furthermore, as mentioned above, their properties are highly dependent on processing. However, it is fair to say that they give more or less the same mechanical properties at ordinary temperatures. These are not far removed from those of common thermoset resins (epoxies, for example). Rather than giving averages or ranges of values for all PMR polyimides for which not all properties have been determined, the following tables and figures show the specific characteristics of PMR-15 polyimide. This is not the most thermostable polyimide, but it is the most widely used.