Dispersion Polymerization And Starch Processing In Deep Eutectic Solvents

With the formation and processing in deep eutectic solvent（DES）as research background,for the first time the dispersion polymerization in deep eutectic solvent was detected through the screening of surfactant.The effects of water content and stirring rate on the morphology of the product particles were investigated.The feasibility of controlled radical polymerization in deep eutectic solvent was explored.Besides,a deep eutectic solvent with the ability of dissolving starch was developed,and the starch processing and modifications in the deep eutectic solvent were studied.The intermolecular interaction and its changes in the two ternary systems were preliminarily explored.The thesis research is consisted of five sections:（1）Free radical dispersion and reversible addition-fragmentation chain transfer polymerization（RAFT）dispersion polymerization in DES.The polystyrene（PS）microspheres were prepared from the dispersion polymerization in DES with the DES as continuous phase,the monomer as dispersed phase,and the suitable surfactant screened.The effects of type and content of surfactant,water content,and stirring rate on the morphology of the product polymer particles were studied through the single-factor method,and the optimal preparing condition was identified.The RAFT polymerization of styrene in DES was then conducted to prepare PS and PMMA microspheres with narrow molecular weight distributions.（2）Dissolution and processing of starch in deep eutectic solvent.In this study,a deep eutectic solvent was developed to dissolve starch,which was consisted of choline chloride and ethylene glycol with the molar ratio of 1:2.The process of dissolving starch in deep eutectic solvent and the changes of starch properties before and after dissolution were studied.It was found out that the recovered starch was soluble in water at room temperature and its chemical structure was not changed,only the hydrogen bond was changed.（3）Starch etherification in ZnCl₂/EG deep eutectic solvents.The hydroxypropyl starch was prepared with DES of choline chloride-ethylene glycol as solvent,and the influencing factors of hydroxypropyl substitution degree were investigated.The etherified starch was characterized by FTIR,XRD,¹H-NMR and SEM.The etherification conditions,influencing factors,and morphological changes of starch samples were obtained.（4）Acidification starch based in deep eutectic solvent.The acidified starch was successfully prepared by acidolysis of corn starch in choline chloride-malonate deep eutectic solvent.The related properties of native starch and acidified starch were characterized and compared by FTIR,DSC,XRD and SEM.The effects of acidolysis temperature and acidolysis time on the properties of acidified starch were studied by single factor method.（5）Mutual solubility,density,viscosity and intermolecular interaction of polycaprolactone-acetone-anti-solvent system.The phase behavior,density and viscosity data of polycaprolactone-acetone-water system and polycaprolactone-acetone-heptane system were measured at 298.2K,308.2K and 318.2K respectively.The effects of polycaprolactone concentration,anti-solvent addition and temperature on the viscosity and density of the system were investigated.Based on the above data,the intermolecular interactions and their changes in the two ternary systems were preliminarily explored.