Composite flame retardant with core-shell structure and preparation method thereof

A technology of composite flame retardant and shell structure, which is applied in the field of core-shell structure composite flame retardant and its preparation, can solve the problems of reduced flame retardant performance and reduced expansion volume, and achieve improved flame retardant performance and increased expansion volume , strong operational effect

Inactive Publication Date: 2012-07-04
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, I did not expect that when the particle size of EG was reduced, a new problem would arise, that is, the gas generated when the intercalation oxidant enclosed between the graphite sheets was heated had not had time to fully expand the graphite sheets , escaped from between the sheets, reducing the expansion volume that can reflect its flame retardancy
For example, after adding 10wt% of EG and pEG particles in RPUF, the oxygen index is 32.5vol% and 23.5vol%, respectively, and the flame retardancy is significantly reduced (Lei Shi, et al. Polymer International, 2006, 55: 862)

Method used

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Examples

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Effect test

Embodiment 1

[0029] 1) First add melamine to water to prepare an aqueous solution with a concentration of 20% by weight, then use a 10% NaOH solution to adjust the pH value of the aqueous solution to 9, heat up to 50°C, stir and reflux for at least 30 minutes, then add formaldehyde solution, and reflux at a constant temperature After reacting for 13 minutes, a clear solution was obtained, and the molar ratio of melamine and formaldehyde added was 1:5.

[0030] 2) Add expandable graphite with an average particle size of 120 μm into water, disperse for 30 min under ultrasonic stirring, prepare an expandable graphite suspension aqueous solution with a concentration of 40% by weight, and make the mass ratio of expandable graphite to melamine 2.5: 1;

[0031] 3) Pour the clear solution obtained in step 1) into the suspension obtained in step 2), first raise the temperature to 50° C. and stir and reflux for at least 30 minutes, then adjust the pH value to 3 with 10% acetic acid solution, and sti...

Embodiment 2

[0034] 1) First add melamine to water to prepare an aqueous solution with a concentration of 5% by weight, then adjust the pH value of the aqueous solution to 8 with a KOH solution with a concentration of 10%, raise the temperature to 50°C, stir and reflux for at least 30 minutes, then add formaldehyde solution, and reflux at a constant temperature After reacting for 15 minutes, a clear solution was obtained, and the molar ratio of melamine and formaldehyde added was 1:4;

[0035]2) Add expandable graphite with an average particle diameter of 100 μm into water, disperse for 30 min under ultrasonic stirring, prepare an expandable graphite suspension aqueous solution with a concentration of 40% by weight, and make the mass ratio of expandable graphite to melamine 3: 1;

[0036] 3) Pour the clear solution obtained in step 1) into the suspension obtained in step 2), first raise the temperature to 50° C. and stir and reflux for at least 30 minutes, then adjust the pH value to 3 wit...

Embodiment 3

[0039] 1) First add melamine to water to prepare an aqueous solution with a concentration of 9.1% by weight, then adjust the pH of the aqueous solution to 9 with a 10% KOH solution, heat up to 65°C, stir and reflux for at least 30 minutes, then add formaldehyde solution, and reflux at a constant temperature After reacting for 10 minutes, a clear solution was obtained, and the molar ratio of melamine and formaldehyde added was 1:3.

[0040] 2) Add expandable graphite with an average particle diameter of 150 μm into water, disperse for 30 min under ultrasonic stirring, prepare an expandable graphite suspension aqueous solution with a concentration of 30% by weight, and make the mass ratio of expandable graphite to melamine 4: 1;

[0041] 3) Pour the clear solution obtained in step 1) into the suspension obtained in step 2), first raise the temperature to 65° C., stir and reflux for at least 30 minutes, then adjust the pH value to 4 with 10% acetic acid solution, and stir for 120...

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Abstract

The invention discloses a composite flame retardant with a core-shell structure, which is formed into dark gray solid particles. The cores of the particles are expansible graphite with an average particle size of 100 to 200 mu m, and the shells of the particles are melamine formaldehyde resin. After the composite flame retardant is subjected to heat treatment at a high temperature of 900 DEG C for 15 seconds, the volume expansibility of the composite flame retardant is 58 to 74ml / g according to measurement. The invention also discloses a preparation method of the composite flame retardant with the core-shell structure. As the flame retardant provided by the invention is formed by coating the expansible graphite particles with a layer of very thin melamine formaldehyde resin, when the particles of the flame retardant with the core-shell structure is heated, the gas generated by the expansible graphite particles cannot escape to the outside immediately due to the protection of the shelllayer formed by polymer on outer layer, instead the gas is released after the graphite sheet layer is opened completely; and thus, the expanded volume of the expansible graphite is increased, and theflame retarding performance is improved greatly. The method provided by the invention adopts simple process, is high in operability and makes the realization of large scale production easy.

Description

technical field [0001] The invention belongs to the technical field of core-shell structure composite flame retardant and its preparation, in particular to a core-shell structure composite flame retardant formed by coating expandable graphite with melamine-formaldehyde resin (MF) and a preparation method thereof. Background technique [0002] With the advancement of science and technology, polymer materials have been widely used in the fields of building materials, automobiles, electronics and aerospace, and play a pivotal role in national economic construction and people's lives. However, the flammability or flammability of most polymer materials has become a safety issue that cannot be ignored, so it is imminent to research and develop flame-retardant polymer materials (A.B.Morgan, et al.John Wily & Sons, Inc.Hoboken, NJ, 2007). [0003] Halogen-free flame retardants have become an important research direction in the field of flame retardants in the world due to their env...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08K9/10C08K7/24C08K3/04C08G12/32C08L75/04
Inventor 唐建华张晓光段宏基
Owner SICHUAN UNIV
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