Table 4. Test Result of NBR 2255 Compound.

Property		T-3	T-4	T-5	T-6	T-7	T-8	T-9
Hardness(shore A)		68	68	66	67	67	68	66
Tensile strength(Mpa)		13.3	14.0	14.1	13.5	14.5	14.5	15.5
Elongation(%)		335	310	340	315	350	330	390
Compression set(%)		26	27	27	28	28	29	29
Ozone-resistance(50 pphm, 40°C, 3day)		No Crack	No Crack	No Crack	No Crack	No Crack	No Crack	No Crack
Low temperature resistance(TR-10)		−50.9	−49.9	−51.5	−51.6	−50.6	−50.5	−51.3
Heat resistance (120°C, 70hr)	Hardness change(%)	+9	+10	+10	+8	+10	+10	+10
	Tensile strength change(%)	+27.1	+14.3	+27.0	+23.0	+24.1	+7.6	+17.4
	Elongation change(%)	−40.3	−40.3	−29.4	−33.3	−32.9	−42.4	−38.5
Oil resistance (ASTM IRM 903, 120°C, 70hr)	Hardness change(%)	−9	−8	−7	−8	−8	−8	−8
	Tensile strength change(%)	+6	−16.4	0	−5.9	−4.8	−4.1	−9.0
	Volume change(%)	+21.2	+20.5	+20.4	+17.5	+20.4	+19.3	+19.0