负载玫瑰香精多孔微球的制备及缓释性能研究

Preparation of porous microspheres encapsulated with rose fragrance and its slow-release performance

以分散聚合合成的单分散聚苯乙烯微球作为种子微球,采用两步种子溶胀法制备多孔聚苯乙烯-二乙烯苯微球,并吸附玫瑰香精制备了香精多孔微球。利用马尔文激光粒度仪、比表面积孔径分布测定仪(BET)、热重分析仪(TGA)、扫描电镜(SEM)对种子微球和多孔微球的粒径、比表面积和孔结构、缓释性能、表观形貌进行了分析表征。结果表明:种球的粒径随着分散介质中无水乙醇体积分数的增大而增加;随着溶胀剂邻苯二甲酸二丁酯(DBP)用量的增加,多孔微球的平均粒径变大,分布变宽;随着交联单体二乙烯苯(DVB)用量增加,多孔微球平均粒径减小,分布变窄;以甲苯为致孔剂制备的多孔微球单分散性最好。当V(DBP):m(种球)=3:1,V(DVB):V(苯乙烯)=4:0时,制备的多孔微球的平均粒径约为4μm。以此多孔微球负载玫瑰香精,可以减缓香精的释放速率,提高起始分解温度,实现对香精的缓释。

Porous microspheres encapsulated with rose fragrance were prepared by adsorption of the fragrance on porous polystyrene - divinylbenzene （PSt - DVB ） microspheres, which were obtained by two - step swell polymerization with the uniform polystyrene mierospheres as seed particles via dispersion polymerization. The surface features of seed particles and porous microspheres were observed by scanning electron microscope （SEM）;the particle size, the specific surface area and pore structure were analyzed and characterized by particle size analyzer and Brunauer, Emmett and Teller （BET） method ; controlled - release performance was tested by thermal gravimetric analysis （TGA）. The results showed that the particle size of the seed particles increases with the increasing of volume fraction of the ethanol. As dosage of the swelling agent, p - dibutyl phthalate （DBP） increases, particle size of the porous mierospheres increases and its distribution becomes wider. As the dosage of cross - linking monomer DVB increases, average particle size of the porous microspheres reduces and its distribution becomes narrower. The best single size dispersion was obtained as the porous microspheres were generated with toluene. The porous PSt - DVB microspheres with the diameter of 4 ixm were obtained when the ratio of V（DBP） ： m（ seed particles） and V（ DVB）： V（St） is 3：1 and 4： 0, respectively. As a result, the release rate of the fragrance can be slow down and initial decomposition temperature can be raised;and then the controlled release of the fragrance can be realized.