Viscosity of potassium oleate in aqueous salt solutions in the presence of poly（propylene glycol）（PPG）,poly（ethylene glycol）（PEG） and poly（vinyl pyrrolidone）（PVP） was measured and the effect of nonionic polymers upon the aggregation of potassium oleate（KOA） in aqueous salt solutions was studied.It has been found that the viscosity of KOA solution in the presence of salt all decreases swiftly by the addition of nonionic polymers.However,the extent of decreasing of the solution viscosity is significantly different.In peculiar,the viscosity of KOA solution in the presence of PEG and PVP is more swiftly than in the presence of PPG.The experimental results suggest the decreasing of the solution viscosity is not due to the hydrophobic interaction of nonionic polymers with surfactants alone.In fact,both the hydrophobic interaction and the hydrophilic interaction of nonionic polymers with surfactants,which determine the morphology of polymer/surfactant complex,are responsible for the decrease of the solution viscosity of KOA in the presence of salt.

The crystallization behaviors of freeze-extracted poly(vinyl chloride)(PVC) samples derived from varying concentration solutions in the medium-sized solvent diisooctyl phthalate(DIOP) were characterized by wide-angle X-ray diffraction(WAXD) and differential scanning calorimetry(DSC).The results of the study show that,as compared with the untreated original PVC sample with chain interpenetrating and entangled,the crystallization ability of the disentangled PVC samples from DIOP are obviously enhanced and the crystallinity increases.The extent of interchain disentanglement and crystallization ability increase with the decrease of the original solution concentration,resulting in the higher content of orderly structure.However,if the concentration dropped too much,the content of orderly structone would decrease.Furthermore,the polymer chains are much more likely to form orderly structure in medium-sized solvent than in small molecules solvent tetrahydrofuran(THF).These results were discussed based on the concepts of entanglement,including topological entanglement and cohesive entanglement,and disentanglement,combined with the morphology and size of polymer chain in the medium-sized solvent.