Preparation method of raw fluorinated silicone rubber with high molecular weight

Abstract

The invention relates to a preparation method of raw fluorinated silicone rubber with a high molecular weight. The preparation method comprises the following steps: adding D3F in a polymerization reaction kettle for dehydration; after dehydration, and then adding fluorine-containing methyl-vinyl-cyclosiloxan and a silicone alcohol lithium salt catalyst; and continuously introducing nitrogen at normal pressure and stirring for polymerization reaction so as to prepare the raw rubber, wherein the polymerization temperature is 110-150 DEG C, the polymerization time is 0.5-3 hours, and the stirring speed is controlled at 1-50r / min. In the method, the fluorine-containing methyl-vinyl-cyclosiloxan with a high ring opening rate is used, thereby solving the problem that vinyl is not distributed on the main chain of the polymer; and the non-balanced silicone alcohol lithium salt is used as a catalytic system and a simple polymerization process and equipment are adopted, thereby solving the heat transfer and mass transfer problems in the polymerization process. Thus, the raw fluorinated silicone rubber with the high molecular weight and high temperature stability is prepared, is more suitable for industrial amplification production, can be widely applied to the environments in the fields of aviation and aerospace, nuclear industry, electronic communication, chemical engineering, medicine, ship and the like, and has good economic benefits and popularization value.

Description

technical field [0001] The invention relates to a preparation method of high molecular weight fluorosilicone rubber raw rubber, in particular to a preparation process of high molecular weight fluorosilicone rubber raw rubber which is stable at high temperature and suitable for industrialization. Background technique [0002] Fluorosilicone rubber is based on -Si-O-Si- as the main chain, with a methyl group (CH 3 -) and 3,3,3-trifluoropropyl (CF 3 CH 2 CH 2 -) and the introduction of a small amount of methyl, vinyl (CH 2 =CH 2 -) Polymers with siloxane chain ends. Fluorosilicone rubber not only has the high and low temperature resistance of silicone rubber, but also has the characteristics of oil resistance and chemical medium resistance of fluororubber. It can be called one of the synthetic rubbers with the best comprehensive performance in the world today. [0003] In order to improve the vulcanization and crosslinking characteristics of fluorosilicone rubber, a small...

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Problems solved by technology

Such as patent CN 1844198A provides a kind of preparation method of fluorosilicone rubber raw rubber, through D 3 F. Vinyl cyclosiloxane and alkaline additives are mixed and dehydrated to prepare fluorosilicone raw rubber. This method uses a polymerization kettle with a screw agitator and is equipped with a devolatilization kettle to solve the mass transfer and Heat transfer problem, but the whole process is cumbersome, the structure of the polymerizer is complicated, and it is difficult to manufacture

Patent CN 101824151A provides an extrusion synthesis method of fluorosilicone polymer, which is to polymerize different polymerization raw materials in different screw segments of a screw extruder. Although this process can be produced continuously, it is difficult to manufacture equipment and the price is high. The feeding sequence of extrusion polymerization has a great influence on the molecular weight and distribution of the polymer, and the overall performance of the compound is unstable.

[0006] Although the existing technology partially solves the problems of mass transfer, heat transfer and unstable quality in the production process of fluorosilicone raw rubber, there is still no effective measure for the problem of uneven distribution of vinyl groups in the main chain of fluorosilicone raw rubber. The process or equipment is complicated, and the difficulty of industrialization is also the problem of these methods

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