二元复合芯材相变微胶囊性能的影响因素

Influential Factors of Performance of Binary Composite Core Material Phase Change Microcapsule

目的在制备相变温度位于温控包装要求2~10℃区间内的微胶囊基础上,通过设计正交试验,研究芯壁比、乳化剂用量、均质速率等因素以及助剂NaCl对微胶囊性能和表观形貌的影响。方法以正十二醇/正癸醇为芯材,以三聚氰胺改性的脲醛树脂作为壁材,采用原位聚合法制备二元复合芯材相变材料微胶囊。利用扫描电子显微镜（SEM）、差示扫描量热仪（DSC）、热重分析仪（TGA）、傅里叶红外光谱仪（FT-IR）等对样品进行分析和表征。结果对微胶囊相变温度的影响程度是均质速率〉芯壁比〉乳化剂用量,对包覆率的影响程度是乳化剂用量〉芯壁比〉均质速率。加入一定量的NaCl能显著提高微胶囊的相变潜热,使微胶囊的包覆率由67.41%升高到89.76%。NaCl的加入可能提高了壁材的性能,增加了微胶囊的坚固程度,提高了芯材的包覆率。所得相变微胶囊表面更加光滑圆整,粒径更加均匀,但NaCl的加入也使得胶囊更加集聚。结论通过便宜易得的原材料,制备出了符合温控包装要求的微胶囊,并通过讨论得出了不同因素对微胶囊性能和表观相貌的影响情况。

On the basis of preparing the microcapsule whose phase transition temperature just keeps 2 - 10 ℃ within the range of temperature-controlled packaging, the work aims to discuss the effects of ratio of core to wall, amount of emulsifier, homogeneous rate and NaC1 on the properties and morphologies of the microcapsules by orthogonal test. The binary composite core microencapsulated phase change material was prepared by in-situ polymerization with binary com- bination phase change material dodecanol/decanol as the core materials, urea and methyl aldehyde as the raw material for the wall with melamine as the modifier. The properties of the products were analyzed and characterized by SEM, DSC, TGA and FT-IR. Experimental results showed that the influence to the phase change temperature of microcapsulethe was the homogeneous rate 〉 the ratio of core 〉 the amount of emulsifier, and the influence to the cladding rate of microcap- sulethe was the amount of emulsifier 〉 the ratio of core 〉 the homogeneous rate. The latent heat of microcapsules was improved greatly by adding NaCI, which made microcapsules encapsulation efficiency increased from 67.41% to 89.76%. The addition of NaCl could improve the performance of the wall, making the microcapsules stronger and improving the cladding ratio of core materials. The surface of phase change microcapsules was more smooth and the particle size was more uniform, but agglomeration phenomenon was more obvious with the addition of NaC1. In conclusion, microcapsules meeting temperature-controlled packaging requirements can be prepared with raw materials that are cheap and easy to get. Different effects of influential factors on the properties and morphologies of the microcapsules are discussed.