Preparation And Properties Of Low Temperature Cool Storage Materials With Polymer Matrix

With the advancement of the global economy and science and technology,the entire world market has gradually formed an inseparable part.The demand for energy is becoming more and more enormous.With the gradual depletion of some non-renewable energy,the search for new energy and the improvement of energy efficiency have become an important issue in today's industrial and social development.With the continuous advancement of science and technology and refrigeration technology,cold chain logistics systems are gradually being developed and established.The cold chain logistics system is a cryogenic logistics process,which is based on refrigeration technology and realizes by refrigeration technology.Although it will increase transportation costs,its highly commercial features,such as ensuring product quality,reducing losses,and increasing cost-effectiveness,have attractedwidespreadattention.Thecoldchainlogisticssystemensures temperature-sensitive products always in their required low temperature environment in all aspects of the supply chain.Cold chain logistics refers to the low-temperature environment in which cold and fresh products have to be keep from the production to the pre-consumption of storage,transportation,sales and other aspects.Cold chain logistics system is realized through temperature control technology.Temperature control technology and various packaging materials combine the temperature-controlled packaging.The cold storage material and the heat insulation material are the main body of the temperature-controlled packaging.The cold storage material provides a cooling capacity for the product packaging environment,and the heat insulation material prevents or reduces the external heat from entering the packaging environment.Phase change materials absorb and release energy during the phase change process,and can effectively solve the mismatch between energy supply and demand in terms of time and space.They are rich in species and have a wide range of temperature control,but they also have widespread leakage.Cold,phase separation and other issues have greatly limited the scope of their applications.For inorganic phase change materials,solving their large degree of undercooling and phase separation is the main subject of research.In addition,with the preparation process of microcapsules,the phase change material is used as a core material to prepare a microcapsule material with one or more wall materials,which is also a major trend in the research of phase change materials.The specific research content is as follows:?1?Study the preparing of cellulose-based SAP,and investigate the water absorption,mechanical properties,and chemical structure of the prepared SAP by orthogonal experiments.Finally,get optimized ratio and reaction conditions of SAP absorption performance.The prepared cellulose-based SAP itself can be directly used as a gel-based cooling agent,and can also be used as a base material for a polymer-based composite cooling agent.It can also be used as a thickening agent for cold storage system to reduce the system's phase separation phenomenon.?2?Prepare an inorganic cold storage agent based on Na2HPO4·12H2O?Na2HPO4·12H2O?as the main energy storage agent and the phase transition temperature is in the range of 2⁸°C.Add antifreeze neutral alumina,Na₄P₂O₇·10H₂O,Na₂O₃Si·9H₂O etc.to reduce the degree of supercooling of the hydrogen phosphate dihydrate cold storage system,and add cold agents such as KCl,Na₂SO₄·10H₂O,Na₂S₂O₃·5H₂O,?NH₄?₂S₂O₈ to reduce the phase transition temperature of Na2HPO4·12H2O cold storage system whose phase change temperature is in the 2⁸°C temperature range.?3?Improve the thermal conductivity of the inorganic cold storage agent based on Na2HPO4·12H2O as the main energy storage agent,and add a suitable thickener to decrease the phase separation phenomenon to prepare a polymer substrate composite coolant gel.?4?Prepare a kind of microcapsules with n-tetradecane as the core material and melamine-modified urea-formaldehyde resin as the wall material.The phase change temperature of the microcapsules is in the range of 2 to 8°C.The microcapsules have relatively high latent heat of phase change and stability.