辣素微胶囊的原位聚合法制备与热降解动力学

在乳液体系中,以尿醛为壁材,以原位聚合法制备了辣素同系物———N-香草基壬酰胺微胶囊。红外光谱证实了尿醛的形成,X-射线衍射显示了同样作为半晶高分子囊壁,尿醛包裹囊心前后出现的结构晶型差异。根据吸附等温曲线假设微胶囊为紧密堆积形式,对于尿醛单体颗粒和尿醛微胶囊的TGA,采用Achar-B rind ley-Sharp-W endworth方法,对两者进行热重数据的处理,以作图法求得了动力学参数,确定了热降解动力学模式函数,回归系数良好。TGA求解的活化能数据证明由于晶型差异,导致单体与微胶囊热稳定性不同,从而与XRD结论一致。

Interfacial in situ polymerization preparation and thermal decomposition kinetics of urea-formaldehyde microencapsules containing capsaicine

Urea-formaldehyde microencapsules containing Npelargonylvanillyl-amide,the homolog of capsaicine,were prepared in emulsion by in situ interfacial polymerization methods.IR showed that urea-formaldehyde had been synthesized by the experiments.XRD showed there were crystal difference between pure urea-formaldehyde and capsule wall.Depending on the absorption curve,the microencapsules were imaged to cumulate tightly.So the data of TGA of pure urea-formaldehyde and microencapsules were analysized by Achar-Brindley-Sharp-Wendworth method.The kinetics parameters were determined and the proper kinetics mode function was indicated.The coefficient of regression R demonstrated that the results were reliable.The value of activation energy confirmed the deduction of XRD test,which meant the crystal difference leads to the discrepancy of thermodynamics stability between pure urea-formaldehyde and capsule wall.