Preparation method of phase change microcapsule

A technology of phase-change microcapsules and phase-change materials, which is applied in the direction of microcapsule preparation, microsphere preparation, chemical instruments and methods, etc., and can solve the problems of increased breakage rate of phase-change microcapsules, incomplete prepolymer reaction, and free formaldehyde content. Higher problems, achieve the effect of reducing residual formaldehyde content, low damage rate, and low free formaldehyde content

Inactive Publication Date: 2015-08-26
SOUTHWEAT UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] None of the reported preparation methods of phase-change microcapsules involves the step-by-step addition of wall material prepolymers and controlling the pH value of the emulsion during the preparation process, so that the reaction of the prepolymers is not complete, and on the one hand, the phase-change microcapsules are broken. rate increases, the compactness is not good, and the leakage rate is high. On the other hand, the residual free formaldehyde content in the phase change microcapsules is relatively high.

Method used

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  • Preparation method of phase change microcapsule
  • Preparation method of phase change microcapsule

Examples

Experimental program
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Effect test

Embodiment 1

[0024] (1) Synthesis of prepolymer

[0025] Add 10ml of distilled water, 4g of melamine and 9.5g of formaldehyde solution with a concentration of 37% in a 250ml three-necked flask, stir and heat to 70°C, adjust the pH value of the solution to 10 with triethanolamine, and react at a constant temperature for 30min to prepare a melamine-formaldehyde resin preparation Polymer. Divide the prepared prepolymer into two equal parts of 5:5.

[0026] (2) Emulsification of phase change materials

[0027] With 4.5g styrene-maleic anhydride copolymer (SMA) as emulsifier, join in 250ml water, heat to dissolve, then add 40g paraffin, emulsify in high-shear emulsifier, emulsification condition is: rotating speed 5000 rpm, The emulsification time is 10min, and the paraffin emulsion is prepared.

[0028] (3) The first drop of prepolymer

[0029] The pH value of the emulsion in (2) was adjusted to 4 with citric acid, stirred at a speed of 800 rpm, and the temperature of the emulsion was 70°C...

Embodiment 2

[0034] (1) Synthesis of prepolymer

[0035] Add 15ml of distilled water, 2g of melamine, 2g of urea and 9.5g of 37% formaldehyde solution into a 250ml three-necked flask, stir and heat to 70°C, adjust the pH value of the solution to 9 with triethanolamine, and react at a constant temperature for 30min to obtain urea- Melamine-formaldehyde resin prepolymer. The prepared prepolymer was divided into three parts of 6:2:2.

[0036] (2) Emulsification of phase change materials

[0037] With 4.5g styrene-maleic anhydride copolymer (SMA) as emulsifier, join in 250ml water, heat to dissolve, then add 45g paraffin, emulsify in high-shear emulsifier, emulsification condition is: rotating speed 10000 rev / min, The emulsification time is 5min, and the paraffin wax emulsion is obtained.

[0038] (3) The first drop of prepolymer

[0039] The pH value of the emulsion in (2) was adjusted to 3 with citric acid, stirred at a speed of 800 rpm, and the temperature of the emulsion was 70°C. Add...

Embodiment 3

[0046] (1) Synthesis of prepolymer

[0047] Add 15ml of distilled water, 4.5g of urea and 9.5g of 37% formaldehyde solution into a 250ml three-neck flask, stir and heat to 70°C, adjust the pH value of the solution to 8 with triethanolamine, and react at constant temperature for 40min to prepare urea-formaldehyde resin prepolymer. Divide the prepared prepolymer into two parts with a ratio of 7:3.

[0048] (2) Emulsification of phase change materials

[0049] With 4.5g styrene-maleic anhydride copolymer (SMA) as emulsifier, join in 250ml water, heat to dissolve, then add 40g paraffin, emulsify in high-shear emulsifier, emulsification condition is: rotating speed 12000 rpm, The emulsification time is 6min, and the paraffin wax emulsion is obtained.

[0050] (3) The first drop of prepolymer

[0051] The pH value of the emulsion in (2) was adjusted to 3 with citric acid, stirred at a speed of 800 rpm, and the temperature of the emulsion was 70°C. Add 70% prepolymer dropwise to t...

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Abstract

The invention discloses a preparation method of a phase change microcapsule. The preparation method comprises the following steps: using a solid-liquid phase change material as a core material and a polymer as a wall material, and preparing a white powdered phase change microcapsule by adopting synthesis of a prepolymer, emulsification of the phase change material and step-by-step dropwise addition of the prepolymer, wherein when the prepolymer is dropwise added each time, the pH value of the emulsion is controlled to enable the prepolymer to be sufficiently reacted. The prepared phase change microcapsule is excellent in properties, low in breakage rate, and low in residual free formaldehyde content; the preparation method of the phase change microcapsule is suitable for preparing the microcapsule by using melamine-formaldehyde, urea formaldehyde resin, phenolic resin, urea-melamine-formaldehyde resin and the like as the shell materials; the preparation method is simple, lower in cost, cheap and accessible in the used raw materials; the preparation method of the phase change microcapsule, disclosed by the invention can be used for effectively reducing the residual formaldehyde content in the phase change microcapsule and expanding the range of application of the phase change microcapsule.

Description

technical field [0001] The invention belongs to the technical field of functional materials, and relates to phase change material processing technology, specifically a preparation method of phase change microcapsules Background technique [0002] Solid-liquid phase change materials change between solid and liquid phases through materials, undergo phase changes in a specific temperature range, and absorb or release heat through phase changes to achieve thermal energy storage and release. Due to the advantages of good chemical stability, large latent heat of phase change, no supercooling and phase separation, wide range of sources, and low price, organic phase change materials have been widely used in phase change materials. However, such materials are easy to flow during the phase transition process, which is limited in practical applications, and microencapsulation is an effective way to solve this problem. [0003] Phase change microcapsules are prepared with phase change ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K5/06B01J13/14
Inventor 杨文彬唐小红张丽徐超星
Owner SOUTHWEAT UNIV OF SCI & TECH
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