Hollow expandable microsphere with super-large particle size and preparation method thereof

Abstract

The invention providesa hollow expandable microsphere with super-large particle size and a preparation method thereof, and belongs to the field of polymer functional materials.The method specifically comprises the steps that airtight monomers, acrylate monomers, 0-50 parts of amide monomers, an initiator, a cross-linking agent and a core material are mixed and stirred in an oil phase kettle, and an oil phase is prepared; deionized water, silica sol, N, N-dimethylformamide, a surfactant, a 1M sodium hydroxide solution and a 0.5 M disodium hydrogen phosphate solution are sequentially added into a water phase kettle to be prepared into a water phase; the oil phase and the water phase are fully stirred in proportion, the oil phase and the water phase are transferred into a homogenization kettle to be homogenized, the homogenization time is 0.5-1 h, the homogenization rotating speed can be 500-10000 rpm, after homogenization is finished, the temperature is increased to 40-80 DEG C, after a reaction is conducted for 24 h, suction filtration and drying are conducted, and hollow expandable microsphere powder with the super-large particle size being 50 micrometers or above is obtained. By means of the treatment scheme, the hollow expandable microsphere powder which is uniform in particle size, free of foaming and large in particle size of 50 micrometers or above is prepared.

Description

technical field [0001] The invention relates to the field of polymer functional materials, in particular to a hollow expandable microsphere with super large particle size and a preparation method thereof. Background technique [0002] Hollow expandable microspheres are polymer plastic microspheres with a core-shell structure composed of airtight thermoplastic polymer shells and hydrocarbons (C4-C12 alkanes) as the core. At room temperature, hydrocarbons are confined by the polymer shell and exist in the core in a two-phase coexistence state. When the microsphere is heated, the hydrocarbon vaporizes and the pressure inside the microsphere increases. At the same time, when the polymer shell reaches its glass At the transition temperature (Tg), the shell becomes soft and malleable. After the microspheres are foamed, the thermoplastic shell changes from thick to thin, the volume increases by more than 80 times, the density decreases significantly, most of the hydrocarbons escap...

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Problems solved by technology

[0003] Although the existing technology can prepare large-pore solid microspheres, there is no further research on hollow core-shell microspheres; and the preparation methods of expandable microspheres reported in current patent documents are mostly based on the acidic silica water phase. For the water phase, the pH of the water phase needs to be adjusted between 1-4 with acidic substances such as hydrochloric acid, and 20-30% of saturated electrolyte needs to be added to keep the water phase stable. The particle size of the prepared microspheres is mostly below 30um, even if The large particle size can be achieved by adjusting the polymerization process, but the uniformity of the particle size of the hollow microspheres cannot be achieved, and the multi-core structure phenomenon and the core-shell structure of the core-shell structure microspheres are not obvious when the particle size is large, so it is impossible to obtain more than 50μm ultra-large expandable microspheres

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