A kind of preparation method of thermally vulcanized fluorosilicone rubber raw rubber

Abstract

The invention relates to a preparation method of heat curing fluorosilicone raw rubber. The preparation method comprises the following steps: adding D3F and D4Vi into a reactor and then dehydrating D3F and D4Vi, adding prepared potassium silanolate catalyst pre-polymer, heating, introducing nitrogen and stirring to carry out polymerization, wherein the temperature is 60-115 DEG C and the reaction time is 20-100min, neutralizing with a neutralizer until the reactant is neutral, and finally, removing small molecular substances from the material, reducing temperature and discharging. Due to the adoption of the potassium silanol catalyst pre-polymer with high activity, the reaction temperature is low, the accelerant is not required, an end-capping reagent is not required in the polymerization process, and the nitrogen purging manner is adopted in the stage of removing the small molecular substances from the material, the volatile matter of the heat curing fluorosilicone raw rubber is reduced; the prepared heat curing fluorosilicone raw rubber can be widely used in the fields of aerospace, petrochemical industry, automobiles, artificial organ, and the like, and has a good promotional value.

Description

technical field

[0001] The invention relates to a preparation method of fluorosilicone rubber raw rubber, in particular to a preparation method of heat vulcanized fluorosilicone rubber raw rubber suitable for aerospace, automobile, machinery, petrochemical, artificial organs and other fields, belonging to the organic chemical industry technology field. Background technique

[0002] Fluorosilicone raw rubber is based on -Si-O-Si- as the main chain, and the silicon atom contains a methyl group (-CH 3 ) and 3,3,3-trifluoropropyl and a small amount of methyl, vinyl (CH 2 =CH-) The linear high molecular polymer of siloxane chain link, its special chemical structure determines that it has both the excellent high and low temperature performance of silicone rubber, and the excellent high temperature resistance, chemical medium resistance and oil resistance of fluororubber , is a new type of synthetic polymer material. Fluorosilicone rubber is mainly divided into liquid fluorosili...

Examples

Embodiment 1

[0039] A preparation method of thermally vulcanized fluorosilicone rubber raw rubber, comprising the following steps:

[0040] (1) The reactor was first ventilated with nitrogen for 1 hour, and then evacuated for 1.5 hours; 2 g of potassium hydroxide was ground into powder, and then mixed with 198.9 g of octamethylcyclotetrasiloxane (D 4 ) and 1.1g of tetramethyldivinyldisiloxane were mixed and reacted at 55°C for 2.5h to obtain a potassium silanolate catalyst prepolymer;

[0041] (2) Add 2000gD 3 F and 4gD 4 Add Vi into the reaction kettle, dehydrate at 50°C and a vacuum of -0.0096MPa for 1h, raise the temperature to 80°C, blow nitrogen, then add 8.0g of the potassium silanolate catalyst prepolymer prepared in step (1), stir and polymerize React for 25 minutes;

[0042] (3) After the polymerization reaction is completed, pass CO 2 And add 1.84g of silicon-based phosphate for neutralization; use pH test paper to detect neutrality to stop CO2 2 ;

[0043] (4) Rapidly rais...

Embodiment 2

[0045] A preparation method of thermally vulcanized fluorosilicone rubber raw rubber, the steps are the same as in Example 1, except that in step (2), after dehydration for 1 hour, the temperature is raised to 80°C, vacuumized, stirred for 25 minutes, and the vacuum degree is -0.006MPa.

Embodiment 3

[0047] A preparation method of thermally vulcanized fluorosilicone rubber raw rubber, comprising the following steps:

[0048] (1) The reaction kettle was first ventilated with nitrogen for 1 hour, and then evacuated for 1.5 hours; 2 g of potassium hydroxide was ground into powder, and then mixed with 198.9 g of octamethylcyclotetrasiloxane (D 4 ) and 1.1g of tetramethyldivinyldisiloxane were mixed and reacted at 55°C for 2.5h to obtain a potassium silanolate catalyst prepolymer;

[0049] (2) 3200gD 3 F and 4gD 4 Add Vi into the reaction kettle, dehydrate for 1 hour at 70°C and a vacuum of -0.01MPa, raise the temperature to 80°C, blow nitrogen, then add 7.2g of the potassium silanolate catalyst prepolymer prepared in step (1), stir and polymerize React for 25 minutes;

[0050] (3) After the polymerization reaction is completed, pass CO 2 And add 1.66g of silicon-based phosphate for neutralization; use pH test paper to detect that it is neutral, and then stop passing CO 2 ...

technical field

[0001] The invention relates to a preparation method of fluorosilicone rubber raw rubber, in particular to a preparation method of heat vulcanized fluorosilicone rubber raw rubber suitable for aerospace, automobile, machinery, petrochemical, artificial organs and other fields, belonging to the organic chemical industry technology field. Background technique

[0002] Fluorosilicone raw rubber is based on -Si-O-Si- as the main chain, and the silicon atom contains a methyl group (-CH 3 ) and 3,3,3-trifluoropropyl and a small amount of methyl, vinyl (CH 2 =CH-) The linear high molecular polymer of siloxane chain link, its special chemical structure determines that it has both the excellent high and low temperature performance of silicone rubber, and the excellent high temperature resistance, chemical medium resistance and oil resistance of fluororubber , is a new type of synthetic polymer material. Fluorosilicone rubber is mainly divided into liquid fluorosili...

Examples

Embodiment 1

[0039] A preparation method of thermally vulcanized fluorosilicone rubber raw rubber, comprising the following steps:

[0040] (1) The reactor was first ventilated with nitrogen for 1 hour, and then evacuated for 1.5 hours; 2 g of potassium hydroxide was ground into powder, and then mixed with 198.9 g of octamethylcyclotetrasiloxane (D 4 ) and 1.1g of tetramethyldivinyldisiloxane were mixed and reacted at 55°C for 2.5h to obtain a potassium silanolate catalyst prepolymer;

[0041] (2) Add 2000gD 3 F and 4gD 4 Add Vi into the reaction kettle, dehydrate at 50°C and a vacuum of -0.0096MPa for 1h, raise the temperature to 80°C, blow nitrogen, then add 8.0g of the potassium silanolate catalyst prepolymer prepared in step (1), stir and polymerize React for 25 minutes;

[0042] (3) After the polymerization reaction is completed, pass CO 2 And add 1.84g of silicon-based phosphate for neutralization; use pH test paper to detect neutrality to stop CO2 2 ;

[0043] (4) Rapidly rais...

Embodiment 2

[0045] A preparation method of thermally vulcanized fluorosilicone rubber raw rubber, the steps are the same as in Example 1, except that in step (2), after dehydration for 1 hour, the temperature is raised to 80°C, vacuumized, stirred for 25 minutes, and the vacuum degree is -0.006MPa.

Embodiment 3

[0047] A preparation method of thermally vulcanized fluorosilicone rubber raw rubber, comprising the following steps:

[0048] (1) The reaction kettle was first ventilated with nitrogen for 1 hour, and then evacuated for 1.5 hours; 2 g of potassium hydroxide was ground into powder, and then mixed with 198.9 g of octamethylcyclotetrasiloxane (D 4 ) and 1.1g of tetramethyldivinyldisiloxane were mixed and reacted at 55°C for 2.5h to obtain a potassium silanolate catalyst prepolymer;

[0049] (2) 3200gD 3 F and 4gD 4 Add Vi into the reaction kettle, dehydrate for 1 hour at 70°C and a vacuum of -0.01MPa, raise the temperature to 80°C, blow nitrogen, then add 7.2g of the potassium silanolate catalyst prepolymer prepared in step (1), stir and polymerize React for 25 minutes;

[0050] (3) After the polymerization reaction is completed, pass CO 2 And add 1.66g of silicon-based phosphate for neutralization; use pH test paper to detect that it is neutral, and then stop passing CO 2 ...

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