The Effect of Cyclodextrins in Polymer Particles Synthesis

The free radical polymerization of styrene in water in the presence of β-cyclodextrin (β-CD) is described. It is found that β-CD could greatly accelerate the polymerization, enhance the final conversion of monomer. The particle-size distribution of the final polymer is also improved than that without β-CD in the system.

Selective removal of phenol by spherical particles of α-,β- and γ-cyclodextrin polymers： kinetics and isothermal equilibrium

Spherical particles of α-,β- and γ-cyclodextrin （CD） polymers to efficiently remove phenol from waste water were prepared by reverse suspension polymerization with epichlorohydrin as crosslinker in liquid paraffin. By controlling the amounts of crosslinker and water, well- defined spherical polymer particles with controllable size were obtained. Due to the selective inclusion associations between CD groups and phenol, these CD spherical polymer particles were demonstrated to be ideal candidates for removal of phenol. Among them β-CD polymer particles showed the best performance. The kinetics and isothermal equilibrium models were used to fit the experimental data of phenol removal from aqueous solution using these CD polymer particles. It was found that the kinetics followed the Ho and Mckay equation, suggesting that the adsorption process of phenol was controlled by diffusion and the host-guest interaction between CD and phenol. Equilibrium isothermal data can be well fitted by the Freundlich equation. The negative free energy change indicated the spontaneous nature of adsorption of phenol by α-,β- and γ-CD spherical polymer particles, while the lowest free energy for β-CD polymer reflected its best adsorption ability, compared to α- and γ- CD polymer particles.

β环糊精对苯乙烯无皂乳液聚合的影响

以苯乙烯为单体,过硫酸钾为引发剂,研究了β环糊精对无皂乳液聚合反应的影响.结果表明,环糊精的引入可以大大加快反应速度,提高单体转化率,并且反应速度随环糊精加入量的增加而增大;同时,环糊精的引入能够减小制得的聚合物微球的粒度分布,使聚合物微球的粒径大小更加均匀,而对粒径的影响不是很大.动力学分析的结果表明,环糊精可以提高单体的反应活性.当环糊精/单体比例增大到0.2时,单体反应活性是空白体系的3.3倍.

无规甲基化β-环糊精对甲基丙烯酸甲酯无皂乳液聚合影响

采用溶液法制备了无规甲基化β-环糊精(RAMEB)/甲基丙烯酸甲酯(MMA)包合物,利用紫外-可见光谱、热重-差热分析等检测手段表明RAMEB与MMA可以形成摩尔比为1∶1的包合物,从而使MMA的热稳定性大大提高。通过RAMEB与MMA的包合作用研究了RAMEB对MMA无皂乳液聚合反应的影响。结果表明,当RAMEB的加入量为4.2×10-4mol时,体系在75℃反应30 min时,单体转化率达89.2%,比同一时间下没有加入RAMEB的空白样的单体转化率提高了30.6%。当RAMEB的加入量为8.4×10-4mol时,聚合反应速率比空白样低,单体的最终转化率与空白样差不多。同时,RAMEB的引入可以使PMMA微球粒径变大,随着RAMEB加入量的增加,聚合物微球的大小越来越均匀。

原位分散聚合法聚合物微球PMMA包覆尿嘧啶的合成及表征研究

本课题采用分散聚合法对抗肿瘤药物进行了原位包覆,研究了其合成工艺以及聚合的机理,并探究了分散剂和反应介质对微球的粒径、粒度分布和包药率的影响。实验结果表明:当无水乙醇取40 g,蒸馏水取60 g所组成的反应介质时,能够制得理想粒径的的聚合物微球,且聚合物微球的粒度分布较为均匀。当单体质量为15 g时,取分散剂3 g可得到理想粒径的微球。当分散剂占单体质量15%~20%时,会取得较高的包覆率。单体聚合的转化率随着引发剂用量的增加而增加,且单体聚合的"高发期"在反应开始后1 h内。