阅读说明：本技术 马来酸酐共聚物/脂肪酸交联的固-固相变材料及制备方法 (Maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material and preparation method thereof ) 是由 曹宇锋 樊冬娌 王锦 袁小磊 姚勇 于 2020-03-02 设计创作，主要内容包括：本发明公开了一种马来酸酐共聚物/脂肪酸交联的固-固相变材料及其制备方法。所述相变材料由包括以下重量份数的原料制备而成：所述相变材料由包括以下重量份数的原料制备而成：马来酸酐共聚物1～5份、脂肪酸5～20份、IIA族或IIB族的金属氧化物或氢氧化物0.15～0.75份。该固-固相变材料的熔融焓在65～135J/g之间,熔融温度在18～70℃之间,具有优异的热稳定性、循环耐久性与形状保持能力,在纺织与建筑行业具有较好的应用前景。同时,该材料的制备方法简单,操作简便,无需后处理,且生产成本低,易于大规模工业化生产。(The invention discloses a maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material and a preparation method thereof. The phase-change material is prepared from the following raw materials in parts by weight: the phase-change material is prepared from the following raw materials in parts by weight: 1 to 5 parts of maleic anhydride copolymer, 5 to 20 parts of fatty acid, and 0.15 to 0.75 part of IIA group or IIB group metal oxide or hydroxide. The solid-solid phase change material has the melting enthalpy of 65-135J/g and the melting temperature of 18-70 ℃, has excellent thermal stability, cycle durability and shape retention capacity, and has a good application prospect in the textile and building industries. Meanwhile, the preparation method of the material is simple, the operation is simple and convenient, the post-treatment is not needed, the production cost is low, and the large-scale industrial production is easy to realize.)

1. The maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material is characterized by being prepared from the following raw materials in parts by weight: 1 to 5 parts of maleic anhydride copolymer, 5 to 20 parts of fatty acid, and 0.15 to 0.75 part of IIA group or IIB group metal oxide or hydroxide.

2. The maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material of claim 1, wherein the maleic anhydride copolymer is selected from any one of polymaleic anhydride-alt-1-octadecene, isobutylene-maleic anhydride copolymer, maleic anhydride-acrylic acid copolymer, polyisoprene-graft-maleic anhydride, polypropylene-graft-maleic anhydride, polyethylene-alt-maleic anhydride, polymethylvinylether maleic anhydride, polystyrene-co-maleic anhydride.

3. The maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material according to claim 1, wherein the fatty acid is any one or a mixture of two or more selected from capric acid, lauric acid, myristic acid, palmitic acid and stearic acid.

4. The maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material of claim 1, wherein the group IIA or IIB metal oxide or hydroxide is selected from MgO, Mg (OH)₂、CaO、Ca(OH)₂、ZnO、Zn(OH)₂Any one of the above.

5. A method for preparing a maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material according to any of claims 1 to 4, comprising the steps of:

step (1): respectively weighing the maleic anhydride copolymer and the fatty acid in corresponding parts by weight, placing the maleic anhydride copolymer and the fatty acid in a stainless steel container, and heating and stirring the maleic anhydride copolymer and the fatty acid to enable the maleic anhydride copolymer and the fatty acid to be melted and mixed uniformly to obtain a melted mixture;

step (2): adding corresponding parts by weight of IIA group or IIB group metal oxide or hydroxide into the molten mixture obtained in the step (1), heating, and continuously mechanically stirring until the color of the molten mixture is changed from white to yellow; the final temperature of heating is 120-150 ℃;

and (3): and (3) pouring the molten blend obtained in the step (2) into a stainless steel mold, and cooling to room temperature to obtain the solid-solid phase change material.

6. The method for preparing a maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material according to claim 5, wherein the heating temperature in step (1) is 70 to 110 ℃.

7. The method for preparing a maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material according to claim 5, wherein in the step (1), the mixture is heated and stirred for 30 minutes.

Technical Field

The invention belongs to the technical field of phase change energy storage, and particularly relates to a maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material and a preparation method thereof.

Background

With the continuous progress of human society and the increasing energy demand, the existing fossil energy can not meet the requirements of people, and people begin to face an unprecedented energy crisis. Meanwhile, human beings generate a great deal of pollution in the process of developing and utilizing fossil energy, and a series of environmental problems are caused. Therefore, the development of a new energy source and the effective utilization of the existing energy source are always important directions for the development of the industry.

The phase-change material has received great attention because of constant temperature and repeated storage and release of heat energy in the phase-change process, and can be used for relieving energy crisis and environmental pollution as a heat energy storage material with potential application value. At present, phase change energy storage materials are widely applied in the fields of solar energy utilization, phase change energy storage type air conditioners, heat preservation clothes, energy storage cookers and the like. The phase-change material specifically comprises four phase-change materials of solid-gas, liquid-gas, solid-solid and solid-liquid. The volume change of the former two is large in the phase change process and gas is generated, so that the requirements of practical application are difficult to meet. The solid-liquid phase change material is a mature phase change energy storage material, but the solid-liquid phase change material is easy to leak in the phase change process, has the hidden trouble of polluting the surrounding environment, and greatly limits the practical application range. The solid-solid phase change material has the advantages of no liquid or gas generation, stable shape, less possibility of leakage and the like in the using process, and is receiving more and more attention. Currently, the solid-solid phase change material preparation methods mainly include physical methods and chemical methods. The solid-solid phase change material prepared by a physical method greatly reduces the mechanical property of the material, is easy to age and leak, pollutes the environment and limits the application range of the material. The solid-solid phase change material synthesized by the chemical method can keep the macroscopic shape stable in the phase change process, can realize the regulation and control of the phase change temperature and the phase change enthalpy by controlling the reaction conditions, and has wide application prospect. However, the solid-solid phase change materials prepared by the chemical method still face a plurality of problems to be solved.

Chinese patent (CN104356306) discloses a comb-like polymer phase-change energy storage material obtained by taking polyethylene grafted maleic anhydride as a supporting skeleton, and taking alcohol with a hydroxyl active group at the end group, ether with a hydroxyl active group at the end group or mercaptan with a mercapto active group at the end group as a phase-change material through a grafting reaction. The method has complex preparation process, needs a large amount of solvents such as benzene, toluene and the like, is not beneficial to environmental protection, and has low grafting efficiency of the phase-change material. Chinese patent (CN108456948) discloses a heat storage and temperature regulation fiber with a skin-core structure, which takes comb-shaped high-molecular phase change material poly (styrene-co-maleic anhydride) -g-n-alkanol as a core layer and takes fiber-forming polymer as a skin layer. The preparation process of the heat-storage temperature-regulating fiber relates to the reaction of grafting two kinds of n-alkanol with different carbon atoms by poly (styrene-co-maleic anhydride), and has the disadvantages of complex process and low heat absorption capacity. Chinese patent (CN108265348) discloses a heat storage and temperature regulation fiber with a skin-core structure, which takes comb-shaped high-molecular phase change material poly (ethylene-g-maleic anhydride) -g-n-alkanol as a core layer and takes fiber-forming polymer as a skin layer. Also, the preparation process of the heat-storage temperature-regulating fiber involves the reaction of grafting two kinds of normal alkanol with different carbon atoms by poly (ethylene-g-maleic anhydride), the process is complex, and the grafting rate of the normal alkanol is low. Therefore, the preparation processes of the various solid-solid phase change materials all involve complex chemical reactions, various toxic and harmful reaction solvents are required, the environment is not protected, and the prepared solid-solid phase change materials have low phase change enthalpy.

Disclosure of Invention

In view of the problems in the background art, the present invention is directed to a maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material and a method for preparing the same. The solid-solid phase change material with a mutual crosslinking framework structure is prepared by taking maleic anhydride copolymer as a framework supporting structure, taking fatty acid as a phase change material and taking metal oxide or hydroxide of IIA group or IIB group as an active crosslinking center. The method has the advantages of simple preparation process, no participation of reaction solvent, high phase change enthalpy value of the prepared solid-solid phase change material, strong shape retention capacity and good application prospect.

In order to achieve the purpose, the invention provides the following technical scheme:

the maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material is prepared from the following raw materials in parts by weight: 1 to 5 parts of maleic anhydride copolymer, 5 to 20 parts of fatty acid, and 0.15 to 0.75 part of IIA group or IIB group metal oxide or hydroxide.

As a preferable mode, the maleic anhydride copolymer is selected from any one of polymaleic anhydride-alt-1-octadecene, isobutylene-maleic anhydride copolymer, maleic anhydride-acrylic acid copolymer, polyisoprene-graft-maleic anhydride, polypropylene-graft-maleic anhydride, polyethylene-alt-maleic anhydride, polymethylvinylether maleic anhydride, and polystyrene-co-maleic anhydride.

As a preferable mode, the fatty acid is any one or a mixture of two or more of capric acid, lauric acid, myristic acid, palmitic acid and stearic acid.

As a preferred embodiment, the group IIA or IIB metal oxide or hydroxide is selected from MgO, Mg (OH)₂、CaO、Ca(OH)₂、ZnO、Zn(OH)₂Any one of the above.

A method of making a maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material as described above, the method comprising the steps of:

step (1): respectively weighing the maleic anhydride copolymer and the fatty acid in corresponding parts by weight, placing the maleic anhydride copolymer and the fatty acid in a stainless steel container, and heating and stirring the maleic anhydride copolymer and the fatty acid to enable the maleic anhydride copolymer and the fatty acid to be melted and mixed uniformly to obtain a melted mixture;

step (2): adding corresponding parts by weight of IIA group or IIB group metal oxide or hydroxide into the molten mixture obtained in the step (1), heating, and continuously mechanically stirring until the color of the molten mixture is changed from white to yellow; the final temperature of heating is 120-150 ℃;

and (3): and (3) pouring the molten blend obtained in the step (2) into a stainless steel mold, and cooling to room temperature to obtain the solid-solid phase change material.

Preferably, in the step (1), the heating temperature is 70 to 110 ℃.

As a preferable mode, in the step (1), the mixture is heated and stirred for 30 minutes.

Compared with the prior art, the invention has the following beneficial effects:

(1) the method utilizes IIA group or IIB group metal oxide or hydroxide as a crosslinking center, and firstly performs acid-base reaction with carboxyl in fatty acid to generate basic salt; then, the basic salt or the copolymer of the basic salt and maleic anhydride and the fatty acid are further dehydrated to generate crosslinking; meanwhile, metal ions in the basic salt can be coordinated with oxygen atoms on carbonyl groups in the maleic anhydride copolymer and the fatty acid to generate further crosslinking, and finally the solid-solid phase change material with a firm mutual crosslinking network structure is formed, so that the problem of leakage of the fatty acid in a molten state is solved.

(2) The solid-solid phase change material prepared by the method has the melting enthalpy of 65-135J/g and the melting temperature of 18-70 ℃, and has a good application prospect in the textile and building industries.

(3) The solid-solid phase change material prepared by the invention has excellent thermal stability and shape retention capability.

(4) The solid-solid phase change material prepared by the invention has excellent cycle durability.

(5) The preparation method is simple, simple and convenient to operate, free of solvent participation, environment-friendly, low in production cost and easy for large-scale industrial production.

Drawings

FIG. 1 is a scanning electron microscope image of the solid-solid phase change material of example 1 (FIG. 1a) and example 3 (FIG. 1 b);

FIG. 2 is a DSC curve of the solid-solid phase change material of example 3;

FIG. 3 is a DSC curve of the solid-solid phase change material of example 3 after 200 cycles without cycles;

FIG. 4 is a thermogravimetric analysis curve of the solid-solid phase change material and palmitic acid of example 3.

Detailed Description

The following examples are given to illustrate specific embodiments of the present invention in detail. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The melting enthalpy value test method of the maleic anhydride copolymer/fatty acid crosslinked solid-solid phase change material comprises the following steps: a differential scanning calorimeter DSC2500 of American TA company is adopted, the test temperature range is-70-100 ℃, the temperature rise and temperature drop rate is 10 ℃/min in a nitrogen atmosphere.