Preparation And Application Of Reticular Structure And Polyurea/Polyurethane Microcapsulated Phase Change Materilas

Aiming at the problems of poor thermal stability and compactness of the conventional preparation of polyurea shell microcapsules phase change materials.On the one hand,a polyurea/polyurethane composite shell microcapsule phase change material was prepared by adding monomeric polypropylene glycol 2000?PPG 2000?to the oil phase reaction system,on the other hand,the microcapsule phase change material having the network structure of the crosslinked structure was prepared by modifying the above composite shell microcapsules with triethanolamine?TEA?having three functionalities.Through the above two routes,the prepared microcapsule phase change material has excellent thermal stability and compactness.Firstly,preparation of a microcapsule phase change materials with a polyurea/polyurethane composite shell was prepared by reacting styrene maleic anhydride copolymer sodium salt?SMAS?as an emulsifying dispersant and isophorone diisocyanate?IPDI?with diethylenetriamine?DETA?and PPG 2000,respectively.The emulsification process was optimized,and the effects of reaction process,core amount and monomer dosage on the surface morphology?SEM?,infrared structure?FTIR?,phase transition property?DSC?,thermal stability and compactness of microcapsules were investigated.The prepared polyurea/polyurethane composite shell microcapsule has better thermal stability and compactness than a single polyurea shell microcapsule.The emulsified particle size distribution range is narrow,and there is no agglomeration between the emulsion particles when the amount of emulsifier is 1.5 g when the emulsification speed and time are 8000 rpm and 10 min,respectively.The microcapsules were prepared by a stepwise stepwise heating process,and the monomer IPDI reaction was complete,and the microcapsule shell was not easily broken.Exploring the effect of the amount of reactive monomer on the performance of microcapsules,it was found that the degree of surface depression of polyurea microcapsules decreased after the addition of PPG 2000.With the increase of the amount of PPG 2000,the thermal stability and compactness of microcapsules gradually increased.The microcapsules have the best thermal stability and compactness when PPG 2000 is 2.0 g.As the amount of DETA increases during the reaction,the number of microcapsule breakage gradually decreases.When the amount of DETA was 3.0 g,the prepared microcapsules were almost no damage.After the preparation,the content of the core material in the microcapsules exceeds 80%,and the melting temperature and the crystallization temperature are 20.90? and 17.16?,respectively.The heat enthalpy is in the range of 84⁸9 J·g^-1,and the heat storage has a good performance.Secondly,the polyurea/polyurethane composite shell prepared above is modified by TEA containing three primary hydroxyl groups,and a polyurea/polyurethane composite shell microcapsule phase change material having a network structure was prepared.The effects of TEA addition mode,TEA and DETA dosage on the performance of microcapsules were investigated.It was found that the thermal stability and compactness of the polyurea/polyurethane composite shell with network structure formed after TEA modification is superior to that of TEA unmodified polyurea/polyurethane linear shell.The stability and compactness of the shell are relatively good when TEA and DETA are added to the reaction system together in the initial stage of the reaction.If TEA is added during or after the reaction,the stability and compactness of the shell are relatively poor,and the damage is severe after high temperature treatment.Investigating the effect of monomer dosage on the performance of microcapsules,it was found that when the amount of DETA was 2.0 g,the thermal stability and compactness of the shell gradually increased with the increase of TEA dosage.120?continued after baking 6 h,the lowest rate of mass loss of only 4.97%when the amount added TEA 3.3 g.Under the same conditions,the mass loss rate of the polyurea/polyurethane linear shell microcapsules which were not modified by TEA was reduced by 7.99%.Finally,the properties of the prepared network structure polyurea/polyurethane microcapsule phase change material and the commercially available microcapsule phase change material were compared and analyzed.The prepared microcapsules were processed into pure cotton fabric by coating finishing to prepare intelligent temperature-regulating fabric with temperature regulation performance,and the finishing process was optimized.The actual temperature control performance of the temperature control fabric was studied by infrared thermal imager and temperature recorder.Studies have shown that the surface contour of the microcapsules prepared in this paper is clear,the adhesion between the shells is less,the thermal stability and compactness are greatly improved compared with the commercially available phase change microcapsules.The amount of microcapsules and the amount of binder have a great influence on the properties of the temperature-regulating fabric.The higher the amount of microcapsules,the lower fabric handfeel and washability of the thermostat fabric.The amount of the binder is higher,the washing durability of the fabric is better,but the fabric handfeel of the fabric is lowered.When the temperature of the fabric is changed,the temperature change rate of the fabric surface is obviously slowed down,indicating that it has a good temperature regulation function.This paper contains figure 46,table 8 and reference 87.