Grafting method of composite film
DATE：2021/4/21 8:21:54 / READ： / SOURCE：This station
Grafting method of composite film
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And initiator. The advantages of the system are as follows: 1) the monomer and photosensitizer exist in the form of mechatronics, and the self shielding effect is small; 2) the monomer and photosensitizer on the surface of the sample exist in the form of mechatronics
The grafting efficiency is high because of the extremely low concentration of monomer. The disadvantage is that the reaction is slow and the radiation time is long. Composite coating production line www.handern.com
(2) In the liquid phase method, photosensitizer, monomer or other additives are mixed together to make a solution, and the polymer sample is directly placed in a constant wave for photo grafting polymerization
The sensitizer is applied to the sample and then put into the solution. In 1977, take? Et al. Invented a special method of liquid phase surface grafting, which solved the problem of solution self-assembly
The disadvantage of shielding problem is that it is easy to generate homopolymer at the same time, and it is difficult to realize continuous operation. The other is Randy et al
A continuous liquid phase method for fiber development. On the one hand, the membrane or fiber is pre impregnated with the solution containing monomer and sensitizer to make the sensitizer adhere to the polymer
On the other hand, the monomer and sensitizer are bubbled in through nitrogen, which not only speeds up the reaction speed, but also improves the reaction efficiency, which is expected to have industrial application prospects. complex
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With or without sensitizer
According to whether or not to add sensitizer can be divided into two categories: ① no sensitizer. First, the surface of the polymer is oxidized to form a layer of peroxide, and then the polymer is oxidized without sensitizer
The desired monomer was grafted onto the surface of the polymer by the addition polymerization of the monomer and the free radical decomposed by peroxide. Chinese Academy of Sciences
Hu Xingzhou et al. Of the Institute of light science used this method to graft light stabilizer methacrylate onto PP and PE films after surface thermal oxidation, which improved the stability of the films.
② Add sensitizer. The sensitizer can not only be introduced to the polymer surface by pretreatment, but also play a role in the light at the same time. Preparation of polymer containing sensitizer
One method is to put the polymer into a container filled with sensitizer vapor. The absorbed content can be adjusted by temperature, and the extracted polymer can be measured by weighing
The amount of sensitizer adsorbed. Another. One method is to dissolve the sensitizer in a volatile solvent, immerse the polymer in the solution, and then take it out for drying
. In order to make the sensitizer adhere to the polymer surface well, some polymers, such as vinyl acetate, can be added into the sensitizer solution, and then the sensitizer can be coated
The photo grafting reaction was carried out in monomer solution. When the monomer is grafted onto the surface of the polymer, it can be connected with the surface of the polymer through chemical bonds, and the polymer surface will be destroyed
It is not only attached to the surface, so it is necessary to confirm how the monomer is connected to the polymer surface after the reaction. Soluble monomers and homopolymers can be used
If the grafted polymer is bonded by chemical bond, the grafted polymer will not be extracted by solvent. Composite coating production line
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The surface properties of materials are one of the most important properties of materials. With the development of high molecular materials industry, polymer materials are required not only to have good intrinsic properties, but also to be stable
And the requirements of surface properties are higher and higher. Such as printing, finishing, coating, dyeing, electroplating, antifogging, polymer materials are required to have appropriate surface properties
. Therefore, surface modification has become a scientific field covering many disciplines, including chemistry, electricity, optics, thermology and mechanics
It's an indispensable part of.
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