HEAT CURED SILICONE RUBBER IOTA HCR 950 U
Description：IOTA HCR 950 U is a silicone master-batch, heat vulcanizing after the addition of a vulcanizing agent (chosen according to the transformation process).
Applications：Extruding, moulding and injecting translucent or colored articles, good compromise mechanical properties, especially rebound resiliency.
Special properties：
Slight replastification after prolonged storage
Good aptitude for processing
No post curing or slight post curing
Good heat stability, up to 200℃
Good compromise between mechanical properties, especially rebound resiliency
Wide possibilities for blending with other master batch
Characteristics：
Type (in accordance with GB/T 5576-1997) …………………… VMQ
Density at 25℃, g/cm3, approx………………………………… 1.11
Natural color…………………………………………………… Translucent
Properties after working：
(1) After addition of 1.25% 2,4-dichloro-benzoyl peroxide (50%), and vulcanization for 8min at 115℃；
(2) After addition of 1.0% 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (45%), and vulcanization for 10 minutes at 170℃。
1. Mechanical properties
1.1 Properties without post-cure (1) (2)
Shore A hardness, approx………………………………… 56 46
Tensile strength, MPa, approx……………………………. 9.7 6.8
Elongation at break, %, approx……………………………. 480 485
Modulus at 100% elongation, MPa, approx……………… 1.3 1.0
Tear strength, kN/m, approx………………………………. 14 15
Compression set (22 h/177°C/25 %), % approx……………52 27
Rebound resilience, %, approx…………………………… 65 52
Linear shrinkage, % approx……………………………… 2.0 3.8
1.2 Properties after post-cure for 4 hours at 200℃
Shore A hardness, approx………………………………… 50 47
Tensile strength, MPa, approx…………………………….. 7.4 8.0
Elongation at break, %, approx…………………………… 365 480
Modulus at 100% elongation, MPa, approx……………… 1.5 1.2
Tear strength, kN/m, approx………………………………. 13 15
Compression set (22h/177℃/25%), %, approx……………34 20
Rebound resilience, %, approx…………………………… 56 50
Linear shrinkage, % approx……………………………… 2.8 4.6
2. Heat stability
Properties after ageing 10 days at 200℃,
Shore A hardness, approx…………………………………… 49 45
Tensile strength, MPa, approx…………………………….. 7.0 6.6
Elongation at break, %, approx……………………………. 350 420
Tear strength, kN/m, approx………………………………. 12 15
3. Heat resistance with the addition of 0.4 parts of additive 744
3.1 Properties after ageing 10 days at 200℃
Shore A hardness, approx………………………………… 47 47
Tensile strength, MPa, approx…………………………….. 6.1 7.0
Elongation at break, %, approx……………………………. 360 500
3.2 Properties after ageing 3 days at 225℃
Shore A hardness, approx………………………………… 49 46
Tensile strength, MPa, approx…………………………….. 6.5 6.8
Elongation at break, %, approx……………………………. 370 490
3.3 Properties after ageing 7 days at 225℃
Shore A hardness, approx………………………………… 47 45
Tensile strength, MPa, approx…………………………….. 6.5 6.1
Elongation at break, %, approx……………………………. 375 460
3.4 Properties after ageing 3 days at 250℃
Shore A hardness, approx………………………………… 46 45
Tensile strength, MPa, approx…………………………….. 6.8 5.1
Elongation at break, %, approx……………………………. 410 405
3.3 Properties after ageing 7 days at 250℃
Shore A hardness, approx………………………………… 48 49
Tensile strength, MPa, approx…………………………….. 5.2 5.1
Elongation at break, %, approx……………………………. 275 290
4. Electrical properties
Dielectric strength (on 2 mm thick slabs), kV/mm, approx…23
Breakdown voltage, kV……………………………………45.4
Dielectric constant at 1 MHz, approx………………………2.8
Dissipation factor at 1 MHz, approx………………………3.5×10-3
Volume resistivity, Ohm.cm, approx………………………2.2×1014
Packaging: IOTA HCR 950 U is delivered in 20 kg carton boxes.
Storage and shelf life: IOTA HCR 950 U may be stored in its original unopened packaging at a temperature below 40℃for up to 18 months from the date of manufacture marked clearly on the packaging.
Past this date, IOTA no longer guarantees that the product meets the sales specification.
