CN-122012022-A - Preparation method and application of solid-solid phase change material

CN122012022ACN 122012022 ACN122012022 ACN 122012022ACN-122012022-A

Abstract

The invention relates to the field of phase change materials, in particular to a preparation method of a solid-solid phase change material, which comprises the following steps of firstly, reacting chitosan and acrylamide in acetic acid solution to obtain a chitosan-acrylamide graft copolymer; and secondly, reacting the chitosan-acrylamide grafted copolymer with oleic acid in an ethanol solution to obtain a solid-solid phase change material. This reaction can render the material ‌ hydrophobic ‌ and ‌ biocompatible. The solid-solid phase change material prepared by the invention takes the chitosan-acrylamide grafted copolymer as a hard segment and oleic acid as a soft segment, so that the high temperature resistance is improved, and the solid-solid phase change material has higher heat storage performance. The solid-solid phase change material prepared by the method has strong operability, and the phase change temperature can meet the use requirement of the pavement in winter in the north.

Inventors

LI DEBAO
CHEN XIAOYAN
MA ZHONGYI
HOU BO
CHEN CONGBIAO
ZHANG WEI

Assignees

中国科学院山西煤炭化学研究所

Dates

Publication Date: 20260512
Application Date: 20260122

Claims (9)

1. A preparation method of a solid-solid phase change material is characterized by comprising the following steps of Step one, in acetic acid solution, chitosan and acrylamide react to obtain a chitosan-acrylamide grafted copolymer; and secondly, reacting the chitosan-acrylamide grafted copolymer with oleic acid in an ethanol solution to obtain a solid-solid phase change material.
2. The method for preparing the solid-solid phase change material according to claim 1, wherein in the first step, before the reaction of chitosan and acrylamide, the mass ratio of acrylamide to chitosan is 3-5, and in the second step, before the reaction of chitosan-acrylamide graft copolymer and oleic acid, the mass ratio of chitosan-acrylamide graft copolymer to oleic acid is 2-4.
3. The method for preparing solid-solid phase change material according to claim 1, wherein the mass percentage concentration of the acetic acid solution is 1-3% in the first step, and the mass percentage concentration of the ethanol solution is 10-90% in the second step.
4. The preparation method of the solid-solid phase change material according to claim 1, wherein in the first step, chitosan and acrylamide are reacted under the condition that a closed reaction vessel is filled with cerium ammonium nitrate serving as an initiator and in a constant-temperature water bath at a temperature of 40-50 ℃ under the protection of nitrogen, and the reaction is carried out for 3-6 hours, so that the obtained chitosan-acrylamide graft copolymer is a jelly.
5. The method for preparing solid-solid phase change material according to claim 4, wherein the mass of cerium ammonium nitrate serving as an initiator is 0.2-0.4% of the total mass of the acrylamide and the chitosan before the chitosan and the acrylamide react.
6. The method for preparing solid-solid phase change material according to claim 1, wherein in the second step, the chitosan-acrylamide graft copolymer used for the reaction of the chitosan-acrylamide graft copolymer and oleic acid is obtained by crushing the chitosan-acrylamide graft copolymer prepared in the first step, purifying with acetone, washing with absolute ethyl alcohol, and drying until the quality is constant.
7. The preparation method of the solid-solid phase change material according to claim 1, wherein in the second step, the chitosan-acrylamide grafted copolymer and oleic acid react under the condition of stirring at a first temperature, refrigerating and separating at 4 ℃ to obtain a refrigerated and separated product, and reacting the refrigerated and separated product in ethanol solution again at a second temperature under the vacuum condition to obtain the solid-solid phase change material.
8. The method for preparing a solid-solid phase change material according to claim 7, wherein the first temperature is 50-70 ℃, the reaction time is 8-10 hours, the second temperature is 80-100 ℃, and the reaction time is 2-6 hours.
9. A solid-solid phase change material prepared by the method for preparing the solid-solid phase change material according to claim 1, wherein the solid-solid phase change material is added into asphalt concrete materials or cement concrete materials for road paving.

Description

Preparation method and application of solid-solid phase change material Technical Field The invention relates to the field of phase change materials, in particular to the field of phase change materials which can be used for road paving. Background When the phase change material is applied to road engineering, the phase change temperature of the phase change material should meet corresponding application requirements so that the phase change material can effectively reduce the damage of the temperature to the road engineering through the phase change effect. For example, by adding certain phase change temperature regulator (phase change material) into road surface material of road engineering, the phase change material will cause the phase change material to melt and change phase when the road surface temperature of road engineering is higher than the phase change temperature, thereby absorbing the peripheral heat and protecting the road surface of road engineering. When the phase change material is added to an asphalt or cement concrete material, the composition of the asphalt or cement concrete material will be changed to some extent. Reasonable addition of the phase change material will allow the cement concrete or asphalt concrete to obtain good mechanical properties while achieving corresponding capacities for absorbing and releasing heat. Thereby reducing the volume of the phase change material and reducing the influence of the phase change material on the mechanical property of the original mixed material. Increasing the specific heat capacity of the phase change material can enable the phase change material to obtain stronger regulating capability on the temperature of the mixture in the process of absorbing heat and releasing heat in a sensible heat mode. Patent CN 201610686246.8 reports the preparation and application of a solid-solid phase change material, but the phase change temperature is above 35 ℃. Patent CN 202010855782.2 reports a geopolymer composite phase change material suitable for road roadbed, which mixes geopolymer slurry with the phase change material and in a specific mold, which is unfavorable for road paving operation and limits the application range. Disclosure of Invention The invention aims to solve the technical problem of providing a phase change material with a phase change temperature within a range of-9-20 ℃ and suitable for paving northern roads. The invention adopts the technical scheme that the preparation method of the solid-solid phase change material comprises the following steps of Step one, in acetic acid solution, chitosan and acrylamide react to obtain a chitosan-acrylamide grafted copolymer, wherein the chitosan-acrylamide grafted copolymer combines the natural biocompatibility of chitosan and the flocculation capability of an acrylamide polymer. By selecting different initiators and optimizing reaction conditions, the structure and performance of the product can be regulated and controlled to meet different application requirements. And secondly, reacting the chitosan-acrylamide grafted copolymer with oleic acid in an ethanol solution to obtain a solid-solid phase change material. This reaction can render the material ‌ hydrophobic ‌ and ‌ biocompatible. In the first step, before the chitosan and the acrylamide react, the mass ratio of the acrylamide to the chitosan is 3-5, and in the second step, before the chitosan-acrylamide graft copolymer reacts with the oleic acid, the mass ratio of the chitosan-acrylamide graft copolymer to the oleic acid is 2-4. In the first step, the mass percentage concentration of the acetic acid solution is 1-3%, and in the second step, the mass percentage concentration of the ethanol solution is 10-90%. In the first step, chitosan and acrylamide react under the condition that an initiator ammonium cerium nitrate is added into a closed reaction vessel under the protection of nitrogen, and the reaction is carried out for 3-6 hours in a constant-temperature water bath at 40-50 ℃, so that the obtained chitosan-acrylamide graft copolymer is jelly. Before the chitosan and the acrylamide react, the ammonium cerium nitrate serving as an initiator is added, wherein the mass of the ammonium cerium nitrate is 0.2-0.4% of the total mass of the acrylamide and the chitosan. In the second step, the chitosan-acrylamide graft copolymer used for the reaction of the chitosan-acrylamide graft copolymer and oleic acid is obtained by crushing, acetone purification, absolute ethyl alcohol cleaning and drying the chitosan-acrylamide graft copolymer prepared in the first step until the quality is constant. In the second step, the chitosan-acrylamide grafted copolymer reacts with oleic acid under the condition of stirring and reacting at the first temperature, refrigerating and separating at 4 ℃ to obtain a refrigerated and separated product, and reacting again in ethanol solution at the second temperature under the vacuum condition to obtain the solid-so