... flexible at -50° C and keep mechanical strength in high temperature;(-60° C----130° C)6>Excellent chemical ... heat treatment size,%≤1.04Brittleness point, max, °C -40°CNo crack5Impermeability0.3MPa,2h Impermeable6Puncture resistance0. ... D751Tearing strength,min, N≥245ASTM D751Brittleness point, max, °C≤-40ASTM D2137Ozone resistanceno cracksASTM D1149Properties after heat agingBreaking strength, ...