Table 2. Test Result of KNB25LM and NBR2255 Compounds.

Property T-1 T-2
Hardness(shore A) 65 66
Tensile strength(Mpa) 15.7 14.1
Elongation(%) 445 340
Compression set(%) +31 +27
Ozone-resistance(50pphm, 40°C, 3day) No Crack No Crack
Low temperature resistance(TR-10) −41.9 −51.5
Heat resistance (120°C, 70hr) Hardness change(%) +10 +10
Tensile strength change(%) +11.5 +27
Elongation change(%) −38.2 −29.4
Oil resistance (IRM 903, 120°C, 70hr) Hardness change(%) −7.0 −7.0
Tensile strength change(%) −3.8 0
Volume change(%) +15.0 +20.4