响应面法优化纳米UF香精微胶囊工艺

采用原位聚合法以脲醛树脂(urea-formaldehyde resins,UF)为壁材制备的微胶囊常在微米级水平上,实验选用吐温80作乳化剂,通过探究实验工艺,制备出了纳米粒径的脲醛树脂香精微胶囊。进行了乳化香精粒径、固含量、壁芯比(UF壁材与香精芯材的质量比,下同)单因素实验,以激光粒度仪测定的微胶囊粒径大小和分布情况为考察指标,确定了3种因素的水平范围。实验表明,当体系固体质量分数小于1%,壁芯比为(2～5):1,乳化香精粒径为50～200 nm时可制得粒径分布均匀的纳米粒径微胶囊。用响应面分析软件进行实验设计,得到了微胶囊粒径与3种因素之间的三次回归模型,其R2值为0.992 7。对模型进行4组实验验证,验证实验结果相对偏差在6%以内,该模型具有较高可信度。

Optimization of UF Fragrance Nano-capsules by Response Surface Analysis

Based on the micron level size of microencapsules prepared by in-situ polymerization method with urea formaldehyde resin as wall material,nano-capsules were prepared with urea-formaldehyde resin as shell,sandalwood fragrance as core and Tween 80 as emulsifier.The shell/core ratio,size of emulsified fragrance,solid content were studied as single effect factor.Three factors′ level was ranged by evaluation of particle size and distribution.It shows that,when the system solid content was less than 1%,shell/core ratio was(2-5):1,emulsified fragrance particle size was 50-200 nm,nano-capsules with homogeneous particle size distribution could be obtained.A quadratic polynomial model between the size of UF partials and the three factors was established by using response surface methodology.In addition,R2 value of the model was 0.992 7,while the relative deviation of the verification experiment was within 6%,which shows that the model is of high reliability in predicting size of UF nano-microcapsules.