Medium viscosity, high reactivity, isophthalic polyester resin with good chemical and heat resistant properties. Fully cured laminates made with DEXATMRES 989 can be exposed to dry temperatures up to 150 °C for long periods, and higher temperatures up to 200 °C for shorter periods of several hours, without any serious loss of mechanical properties. DEXATMRES 989 is developed to meet exacting thermal and electrical requirements but is equally suitable for use in other high-performance applications where high strength reinforcements such as glass cloth or woven roving should be used.