Preparation And Characterization Of N-Tridecane/Polystyrene Microcapsule Phase Change Materials

Due to the increasing energy crisis,the application and utilization of new energy presently has become an important topic.The new microcapsule phase change materials with specific function are effective in solving this problem.Microcapsule phase change materials are a kind of new materials to change the storage and transportation methods of foodand medicine,which has great influence on the development of food and medicine industry.This subject is based on the preparation of low temperature microcapsule phase change materials for temperature-controllable packaging products to ensure the goodquality in the storage and transportation processes.In the past,microcapsule phase change materials have some disadvantages,such as the leakage and low loading rate of core material.In addition,the shell materials show low thermal conductivity,which affects the temperature-controlling ability of microcapsule phase change materials.Therefore,it is a very meaningful work to study the microcapsule phase change materials with high loading rate,high particle strength and good thermal conductivity.In this paper,microcapsule phase change materials were prepared by suspension polymerization with polystyrene as shell material and with n-tridecane as core material.We investigated the effects of reaction temperature,stirring rate,initiator amount,dispersant amount,oil-to-water ratio on the particle size and distribution,loading rate,enthalpy value and other properties of microcapsule phase change materials by FT-IR,POM,TG and DSC.The main conclusions are as follows:1.The subject explored the microcapsule phase change materials with the 50wt%content of core material,being achieved by polymerizing the styrene monomer of 20 g in the existence of n-tridecane of 20 g.The effect of reaction conditions on the properties of microcapsule phase change materials was investigated in detail.By optimizing the enthalpy,loading rate,product yield,particle size and distribution of microcapsule phase change materials,the optimum reaction condition was given below: reaction temperature 80±2oC,stirring rate 450 r/min,BPO mass5 wt%,dispersant PVA5 wt%,dispersant TCP 5 wt%,oil-to-water ratio 1: 3.3.2.The microcapsule phase change materials were prepared and characterized under the optimum conditions.The results showed that microcapsule phase change materials have core-shell structure and uniform size distribution between 300-700?m.3.The shell material polystyrene was prepared in the microcapsule phase change materials under the optimum conditions,preventing the volatilization of n-tridecane and improving the thermal stability.The phase transition enthalpy of microcapsule phase change materials is 48.13 J/gwith the loading rate of 46.28%,which can meet the functional requirement of heat/cold storage.The maximum number average molecular weight of polystyrene in the microcapsule phase change materials under the optimum conditions is 6.4*103.The subject is of great significance to develop the cold storage packaging materials.The microcapsule phase change materials will be applied to corrugated carton composites to realize its cold storage function greatly improving people's life.