BLUESIL ADD 744 is added to HCR’s on a 2-roll mill.
Doses of 0.3 to 0.5 % by weight with respect to the HCR pre-catalysed compound have a very pronounced effect on the heat stability of silicone elastomers, up to a temperature of 250°C.
Comment: With transparent HCR compounds BLUESIL ADD 744 can cause slight yellowing.
Improving the heat stability of MF 135 U and MF 175 U by adding BLUESIL ADD 744:
For example, the table below gives the change in mechanical properties for MF 135 U and MF 175 U with and without the addition of BLUESIL ADD 744, under various heat ageing conditions.
These properties are obtained after adding 2-4 dichloro benzoyl peroxide with 50 % active ingredients (Peroxide E) and curing for 8 minutes at 115 °C.
|MF 135 U||100||100||0||0|
|MF 175 U||0||0||100||100|
Properties after post-curing for 4 hours at 200 °C:
|Shore A hardness||40||40||70||70|
|Tensile strength MPa||7.1||7||9.5||9.7|
|Elongation at break %||390||400||280||310|
|Modulus at 100 %, MPa||0.8||0.7||2.7||2.6|
|Modulus at 300 %, MPa||3.5||3.3||-||-|
|Tear strength, kN/m||21||21||21||21|
Properties after heat ageing for 3 days at 225 °C
|Shore A hardness||46||44||80||78|
|Tensile strength, MPa||5.8||6.2||6.2||6.4|
|Elongation at break, %||250||290||120||200|
Properties after heat ageing for 7 days at 250 °C
|Shore A hardness||B||44||B||81|
|Tensile strength, MPa||-||5||-||5.3|
|Elongation at break, %||-||230||-||170|
B = Brittle
BLUESIL ADD 744 储存温度介于 -5°C / 23°F 和 40°C / 104°F 之间时，从生产日期开始产品保质 18 个月
BLUESIL ADD 744
Red translucent paste.
BLUESIL ADD 744 is a particularly effective heat stabiliser for heat cure silicones. It protects cured compounds to a temperature of 250°C for prolonged periods