Preparation method of phase-transition temperature adjustable comb-like copolymer solid-solid phase change material

Abstract

The invention relates to a preparation method of a comb copolymer solid-solid phase change energy storage material with adjustable phase change temperature. (1) According to a certain molar ratio, weigh a triisocyanate coupling agent, Methyl ether and polyethylene glycol; (2) Dissolve polyethylene glycol monomethyl ether and triisocyanate coupling agent in the solvent respectively, and heat the reaction under the protection of nitrogen to obtain polyethylene glycol monomethyl ether with special end groups solution; (3) Dissolve polyethylene glycol in a solvent, add it to the above solution, and heat reaction under nitrogen protection to obtain a comb-shaped copolymer solution; (4) Quickly evaporate the solvent, and naturally cool to obtain a comb-shaped copolymer Solid-solid phase change energy storage materials. The comb-shaped copolymer phase change material prepared by the present invention has adjustable phase transition temperature, large phase transition enthalpy, and good thermal stability; and the preparation process does not need to use other polymer skeleton support materials or coating materials, and directly adopts solution contact Branch polymerization reaction, simple process, easy to control.

Description

technical field [0001] The invention relates to the field of preparation of phase change energy storage materials, in particular to a preparation method of a comb-like copolymer solid-solid phase change energy storage material with adjustable phase change temperature. Background technique [0002] Energy is the basis for human survival. However, with the rapid development of global industry, energy supply is becoming increasingly tense. People are paying more and more attention to the development of new energy and the economical use of traditional energy. The challenges facing the energy field today are: the development of new energy has never made a breakthrough; the traditional energy supply has caused a lot of waste due to the mismatch in space and time. Due to its ability to automatically adjust the temperature and store heat within a certain temperature range according to changes in the external environment, phase change materials have attracted great attention. In rec...

AI Technical Summary

Problems solved by technology

Since the phase-change substance polyethylene glycol (PEG) is mainly combined with the matrix epoxy resin by physical cross-linking, there are problems such as uneven dispersion and poor compatibility, which greatly affect its energy storage efficiency and thermal cycle stability.

Invention patent CN 102061148 A discloses a preparation method of an interpenetrating network-shaped phase change material. The network monomer N-methylolacrylamide, cross-linking agent N, N-methylenebisacrylamide, and phase change material are polymerized Ethylene glycol is dissolved in distilled water and ultrasonically dispersed, and the resulting interpenetrating network structure improves the strength and mechanics of the gel, but its phase change reversibility is not very good

There are some unavoidable problems in the solid-solid phase change materials prepared by physical blending or encapsulation technology: ①Composite phase change materials made in the form of blending are difficult to overcome the diffusion and migration of low melting point phase change materials after melting, There is a problem of phase separation between the carrier matrix and the carrier matrix; ②The addition of a certain carrier to the phase change material leads to a decrease in the heat storage capacity of the entire material, and the energy density of the material is small; ③The addition of the phase change material to the carrier leads to a decrease in the mechanical properties of the material The decrease of the hardness, strength, flexibility and other properties of the entire material is greatly lost, so that the life is shortened, the aging is easy, the working substance leaks, and the environment is polluted.

Invention patent CN 102516471 A discloses a comb-shaped polymer phase change material using free radical polymerization with alkyl chains as the main link and monomethyl ether polyethylene glycol as the branch chain. Due to acrylic polyethylene glycol monomethyl ether The free radical polymerization of ester and acrylamide monomers is difficult to control the density of crosslinking points. If the crosslinking is excessive, it will become a thermosetting polymer and lose its phase change heat storage capacity.

Peng Xi (Energy Conversion and Management 2009, 50, 1522) used a two-step method to graft MPEG onto the main chain containing vinyl and styrene groups to prepare a comb-shaped solid-solid phase change material with a melting enthalpy higher than 108J / g, but the process is more complicated and difficult to control

Ahmet Sari (Materials Chemistry and Physics, 2012, 133, 87) grafted polyethylene glycol onto the polystyrene main chain to form a comb-shaped polymer with a phase transition enthalpy of 143.6 J / g and good thermal stability , but prone to phase separation

Images