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.