HEAT CURED SILICONE RUBBER IOTA HCR 940 U

Description:

IOTA HCR 940 U is a silicone master-batch, heat vulcanizing after the addition of a vulcanizing agent (chosen according to the transformation process).

Applications:

IOTA HCR 940 U is specially recommended for moulding, injection and extrusion of articles with a good compromise of mechanical properties.

Special properties:

Slight replastification after prolonged storage

Easy to process

Without post-cure or slight post-cure

Good heat stability, up to 225℃, or even 250 ℃ with additive 744

Wide range of blends possible with other master-batches

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(at 50%), and vulcanization for 8min at 115℃

(2) After addition of 1.0% 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane at 45%, and

vulcanization for 10 minutes at 170℃

1. Mechanical properties

1.1 Properties without post-cure                               (1)   (2)

Shore A hardness, approx…………………………………     41   36

Tensile strength, MPa, approx……………………………    8.2   7.6

Elongation at break, %, approx……………………………   655   790

Modulus at 100% elongation, MPa, approx………………0.6   0.6

Tear strength, kN/m, approx……………………………….    13   15

Compression set (22h/177°C/25%), % approx…………… 51   47

Rebound resilience, %, approx………………………………   52   43

1.2 Properties after post-cure for 4 hours at 200℃

Shore A hardness, approx……………………………………    46   42

Tensile strength, MPa, approx………………………………   7.8   9.1

Elongation at break, %, approx………………………………  515   650

Modulus at 100% elongation, MPa, approx…………………1.0   0.8

Tear strength, kN/m, approx…………………………………    14   15

Compression set (22h/177℃/25%), %, approx……………27   20

Rebound resilience, %, approx………………………………   61   48

2. Heat stability

2.1 Properties after ageing 7 days at 177℃

Shore A hardness, approx…………………………………      45   43

Tensile strength, MPa, approx……………………………     6.9   7.2

Elongation at break, %, approx……………………………    425   515

Modulus at 100% elongation, MPa, approx………………  1.1   0.9

Tear strength, kN/m, approx……………………………….     12   15

2.2 Properties after ageing 10 days at 200oC

Shore A hardness, approx…………………………………      45   45

Tensile strength, MPa, approx……………………………     6.6   5.8

Elongation at break, %, approx…………………………….    405   415

Modulus at 100% elongation, MPa, approx………………  1.2   1.1

Tear strength, kN/m, approx………………………………      13   12

2.3 Properties after ageing 3 days at 225℃

Shore A hardness, approx……………………………………     42   47

Tensile strength, MPa, approx………………………………    6.7   5.5

Elongation at break, %, approx………………………………   420   440

Modulus at 100% elongation, MPa, approx…………………1.2    1.6

Tear strength, kN/m, approx…………………………………    12    9

3. Heat resistance with the addition of 0.4 parts of additive 744

3.1 Properties after ageing 7 days at 177℃

Shore A hardness, approx……………………………………    44   43

Tensile strength, MPa, approx………………………………    7.8   8.1

Elongation at break, %, approx…………………………….    490   590

Modulus at 100% elongation, MPa, approx………………… 1.0   0.9

Tear strength, kN/m, approx……………………………….     13   16

3.2 Properties after ageing 10 days at 200℃

Shore A hardness, approx……………………………………    44   44

Tensile strength, MPa, approx………………………………    7.3   7.5

Elongation at break, %, approx…………………………….    440   540

Modulus at 100% elongation, MPa, approx………………… 1.2   1.1

Tear strength, kN/m, approx…………………………………    13   16

3.3 Properties after ageing 3 days at 225℃

Shore A hardness, approx……………………………………    44   40

Tensile strength, MPa, approx………………………………    7.5   6.7

Elongation at break, %, approx…………………………….    460  550

Modulus at 100% elongation, MPa, approx………………    1.1   1.0

Tear strength, kN/m, approx…………………………………    14   16

3.4 Properties after ageing 7 days at 225℃

Shore A hardness, approx……………………………………    45   43

Tensile strength, MPa, approx………………………………    6.3   6.0

Elongation at break, %, approx…………………………….    395   500

Modulus at 100% elongation, MPa, approx………………    1.2   1.0

Tear strength, kN/m, approx…………………………………    13   15

3.5 Properties after ageing 3 days at 250℃

Shore A hardness, approx……………………………………    43   42

Tensile strength, MPa, approx………………………………    6.4   5.6

Elongation at break, %, approx…………………………….    410   500

Modulus at 100% elongation, MPa, approx…………………  1.2   1.0

4. Electrical properties

After addition of 1.1% 2-4 dichloro-benzoyl peroxide (at 50%) and vulcanization for 8 min at 115℃.

Dielectric strength (on 2 mm thick slabs), kV/mm, approx…19

Dielectric constant at 1 MHz, approx………………………2.8

Dissipation factor at 1 MHz, approx…………………………7.0×10^-3

Volume resistivity, Ohm.cm, approx………………………2.0×10¹⁴

Packaging:

IOTA HCR 940 U is delivered in 20 kg carton boxes.

Storage and shelf life:

IOTA HCR 940 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 specifications.