聚合物中空微球的制备及粒径控制

Preparation and Size Control of Polymer Hollow Microspheres

采用种子乳液聚合法制备了高羧基含量的多层核/壳聚合物微球,然后用氨水对其进行碱处理,形成了粒径均一且内部具有空腔结构的聚合物微球。通过傅里叶变换红外光谱仪对核壳微球上的官能团进行分析;结合电导滴定曲线及Zeta电位值对聚合物微球亲水核/疏水壳的结构进行确定。研究了乳化剂十二烷基硫酸钠(SDS)用量和碱处理过程中的碱酸摩尔比对微球粒径及形貌的影响。结果表明,核、多层核/壳和聚合物中空微球的粒径及空腔直径均随SDS用量的增加而减小;碱酸摩尔比的增加有利于聚合物微球体积的膨胀,所得中空微球粒径及空腔直径均随碱酸摩尔比的增加而增大。控制乳化剂用量为0.01~0.03 g,碱酸摩尔比为1.0~2.0,可制得粒径为355~790 nm、空腔为118~450 nm的聚合物中空微球。

The multilayer core/shell polymer microspheres with high carboxyl content were prepared by seed emulsion polymerization,then treated with ammonia to form monodisperse polymer hollow microspheres. The functional groups of the core/shell microspheres were characterized by FT-IR,and the structure of the hydrophilic core/hydrophobic shell was confirmed by the conductometric titration curve and the Zeta potential analyze. The effects of the content of sodium dodecyl sulfate（ SDS） and the mole ratio of alkali to acid in the process of alkali treatment on the size and morphology of microspheres were studied. Results show that the diameter of core,multilayer core/shell and hollow microspheres as well as the hollow size decrease with the increasing of SDS content. Enhancing the mole ratio of alkali to acid is favorable to the volume expansion of microspheres and leads to the increasing of both the diameter of hollow microspheres and the hollow size inside. Furthermore,the polymer hollow microspheres with the diameter of 355 ~ 790 nm and hollow size of 118 ~ 450 nm could be obtained by varying SDS mass from 0. 01 g to 0. 03 g and the mole ratio of alkali to acid from 1. 0 to 2. 0.