Application of the hottest rare earth surface modi

Application of rare earth surface modifiers in mineral reinforced Flame Retardant Composites

Engineering of general plastics and high performance of engineering plastics are the main melody of the research on the functionalization of polymer materials. The functionalization of polymer materials mostly adopts alloying (a) to check whether the friction active part should be filled with lubricating oil, blending (b), compounding (c) and other ABC methods. For inorganic mineral reinforced polymer composites, the melting point of many additive flame retardants is higher than the processing temperature of the base resin. Therefore, in the processing process, flame retardants and inorganic mineral powder are dispersed in the base resin through physical forms. It is very important to improve the dispersion and compatibility of inorganic powder in the base resin and strengthen the compatibility or compatibility between inorganic powder and flame retardant

generally, people use silane, titanate, aluminate, aluminum titanium composite ester, phosphate, borate ester and other coupling agents to activate the surface of inorganic powder, improve the hydrophobicity or lipophilicity of inorganic particles by changing the polarity or charge state of the surface of inorganic particles, and strengthen the compatibility between inorganic materials and base resin. This compatibility is enhanced by improving the winding of polymer chains and the force between molecules. The binding force is not strong, and the improvement of compatibility is limited. The rare earth surface modifier WG-2, which was successfully developed by Beijing Institute of chemical industry and Guangdong weilinna functional materials Co., Ltd., introduced light rare earth elements into the hydrophilic and lipophilic structure of traditional coupling agents. The valence electron layer structure of rare earth atoms has many empty orbitals, which is easy to accept the lone pair electrons provided by many ligands to form coordination bonds. The bond energy of coordination bond is much larger than that of van der Waals force. Therefore, in addition to the conventional coupling effect, rare earth surface modifiers may also form a multidirectional coordination combination centered on rare earth elements between inorganic powders/substrate resins/flame retardants/other additives, so that the compatibility and/or compatibility between the components of the formula can be synchronously improved, so as to comprehensively improve the performance of the composite

application in flame retardant pa66/layered silicate composite system

this study uses layered silicate as a filling modifier in non glass fiber reinforced PA66 to improve the dimensional stability, heat resistance and mechanical properties of the material

surface treatment of layered silicates

the experiment uses layered silicates without surface activation treatment and layered silicates fillers treated with rare earth surface modifiers for comparison test

at room temperature, add 2 parts of rare earth surface modifier WG-2 to 100 parts of layered silicate powder in a 5-liter high-speed mixing pot, start stirring and heating, and maintain high-speed stirring at 80~110 ℃ for 10 minutes to obtain rare earth activated layered silicate. This activated filler can directly enter the next processing procedure. If it is not used continuously, the treated activated powder should be dried in a blast oven at 120 ℃ for 2 hours before processing

there are only thousands of flame retardant pa66/rare earth activated layered silicon enterprises, and the formula and performance of the acid salt composite system

the formula and corresponding performance test data of PA66/rare earth activated layered silicate flame retardant composite system are shown in Table 1. The flame retardant used in this experiment is still conventional polybrominated aromatic compounds

it can be seen from table 1 that the thermal deformation temperature of the filler formula treated with rare earth surface modifier has obvious changes compared with the untreated filler formula. On the premise of maintaining the same variety and quantity of flame retardants and other additives, the thermal deformation temperature of 3 # and 1 # is higher than 9 ℃; Keep the same variety and quantity of flame retardants and other additives, reduce the addition ratio (reduce the impact of flame retardants or additives on performance), 4# compared with 2# the heat deformation temperature is 26 ℃ higher. This shows that the filler treated with rare earth surface modifier has a good effect on the increase of thermal deformation temperature, and effectively improves the compatibility between layered silicate and PA-66 resin. The introduction of rare earth surface modifier has no adverse effect on the flame retardancy of the composites. In terms of mechanical properties, 4# is also better than 2#. Other performances meet the purpose of this test. Rare earth surface modifier is expected to become a potential surface treatment agent

application in flame retardant pa6/silicate composite system

in this study, silicate is used as filling modifier in non glass fiber reinforced PA6 to improve the dimensional stability, heat resistance and mechanical properties of the material to meet the performance requirements of the product. The filler used in this study is wollastonite

surface treatment of silicate powder

the experiment uses the original silicate without any surface activation treatment and the silicate filler treated with rare earth surface modifier for the control test. The activation treatment method of wollastonite is completely the same as the layered silicate treatment method previously mentioned

formula and performance of fire-retardant pa6/rare earth activated silicate composite system

formula and corresponding performance test data of fire-retardant PA6/rare earth activated silicate composite system are shown in Table 2. The flame retardant used in this experiment is also a conventional polybrominated aromatic compound

Table 2 formula and performance data of pa6/rare earth activated silicate flame retardant composite system

from table 2, it can be seen that the thermal deformation temperature of the filling formula 2 # treated with rare earth surface modifier is significantly changed compared with that of the untreated filling Formula 1 #. The thermal deformation temperature of formula 2 is 16.5 degrees higher than that of Formula 1. This again shows that the filler treated by rare earth surface modifier has a good effect on the increase of thermal deformation temperature. The mechanical properties also changed significantly. The comprehensive performance of 2 # formula is better than 1 #. Notch impact strength nearly doubled; The bending strength is increased by 8%

application in halogen-free flame retardant polypropylene

although the literature reports that many halogen-free flame retardants have been successfully applied to the flame retardant of polyolefins, except for a few intumescent flame retardants of phosphorus nitrogen system, the halogen-free flame retardants that are really put into industrial application are still mainly inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide. Generally, in order to meet the requirements of flame retardancy, the addition of magnesium hydroxide is as high as 60%. Although it meets the requirements of flame retardancy, the basic physical and mechanical properties of polypropylene are greatly deteriorated, because magnesium hydroxide is incompatible with polypropylene. How to solve the surface activation treatment of magnesium hydroxide has become the key to improve the comprehensive properties of halogen-free flame retardant polypropylene

Table 3 experimental formula of rare earth treated magnesium hydroxide flame retardant PP

Ou Yuxiang, Li Jin and others in the national flame retardant Laboratory of Beijing University of technology used the high-purity synthetic magnesium hydroxide produced by deadsea bromide company of Israel as the research object. Magnesium hydroxide is treated by dry method and wet method. The wet method is to pre dissolve the rare earth surface modifier in organic solvent and coat and activate magnesium hydroxide; The dry method is to blend rare earth surfactant and magnesium hydroxide, stir them, heat them to 110 ℃ and keep them for 10min for direct activation treatment. The magnesium hydroxide samples before and after activation were tested for flame retardant formula. The polypropylene base resin is pp2401 produced by Yanshan Petrochemical, and the addition amount of magnesium hydroxide is 65%. The experimental formula is shown in Table 3, and the performance test data is shown in Table 4

Table 4 test data of rare earth treated magnesium hydroxide flame retardant PP

before processing, put magnesium hydroxide raw material and polymer PP into a vacuum drying oven at the same time, dry to constant weight under vacuum of 0.09mpa and temperature of 110 ℃, take it out after cooling and weigh it according to the following formula

put the weighed mixture into a high-speed mixer and mix it evenly, then extrude and granulate it with a twin-screw extruder at 200 ℃. The test results of mechanical and flame retardant properties are shown in Table 4

from the data in Table 4, it can be seen that after adding 65% untreated magnesium hydroxide to polypropylene, although the flame retardant performance has been greatly improved (the flame retardant level reaches V-0, and the oxygen index is close to 30), the mechanical properties, especially the elongation, have decreased significantly, which is mainly caused by the high addition of magnesium hydroxide and the hydrophilic and oleophobic properties of the surface. The dispersion of activated magnesium hydroxide in polypropylene and its compatibility with polypropylene have been significantly improved due to the improvement of its surface properties. When it is added to PP, compared with blank PP resin, the mechanical properties of PP with its flame retardance also show a downward trend, but compared with non activated magnesium hydroxide flame retardant PP, the elongation and notch impact strength are greatly improved (the elongation can be increased by dozens to onehundred times, and the notch impact strength can be increased by two to three times), and the improvement of tensile strength and bending strength is not obvious. At the same time, its surface appearance has been greatly improved. It can also be seen from table 4 that the smoke suppression performance of the modified magnesium hydroxide is further improved

for the same kind of magnesium hydroxide, comparing the data of dry and wet methods, it can be seen that the dry method has slightly advantages over the wet method in tensile strength, bending strength and vertical combustion, while the elongation and notch impact strength are slightly weaker than the wet method

conclusion

the above experimental results show that for the polymer/inorganic mineral powder flame retardant composite reinforcement system, using rare earth surface modifier to activate the inorganic mineral powder can effectively improve the compatibility between the inorganic mineral powder and the polymer substrate. The specific manifestations are:

(1) pa66/rare earth activated layered silicate flame retardant composite system compared with the composite system without activation treatment, the thermal deformation temperature increases significantly, tensile Bending strength has also improved

(2) compared with the composite system without activation treatment, the thermal deformation temperature of pa6/rare earth activated silicate flame retardant composite system is significantly increased, and the mechanical properties are comprehensively improved

(3) compared with the composite system without activation treatment, the elongation and notch impact strength of pp/rare earth activated magnesium hydroxide flame retardant composite system have been significantly improved, and the apparent state of the product has also been significantly improved

(4) rare earth surface modifiers have no adverse effect on the flame retardancy of polymer/inorganic mineral powder flame retardant composite reinforcement system

therefore, the activation treatment of inorganic mineral powder by rare earth meter servo valve surface modifier effectively improves the compatibility between inorganic mineral powder and polymer matrix resin, and comprehensively improves the mechanical properties of flame retardant composite system without affecting the flame retardancy

originally published in China Plastics and rubber

Beijing Research Institute of chemical industry Chen Yu, Liu Zhengduan, Wang Zhaohui

Guangdong weilinna functional materials Co., Ltd. Zheng de (end)