The Study On Preparation And Properties Of Micro-encapsulated Phase Change Materials/PAN Fiber

In this thesis, we researched the preparation of microencapsulated phase change material (MEPCM) and thermo-regulated fibers in detail. The MEPCM prepared by interfacial polymerization technique that used instant emulsion method instead of conventional emulsifiers. Paraffin MEPCM was prepared by interfacial polymerization technique using toluene-2,4-diisocyanate (TDI) and piperazine (PIP) as monomers.We introduced the influences of oleic acid concentration, sodium hydroxide concentration, saponification time and emulsion speed on the formation and diameter of microcapsules. Then, the influences of monomer structure on the performance of MEPCM was researched. The shell used respectively TDI and PIP, ethylenediamine (EDA) and trimesoyl chloride (TMC), PIP and TMC, and TDI and EDA as monomers.30’paraffin as core material to prepare four different species of MEPCM by interfacial polymerization. Next it comparatively studied the morphology, acid and alkali resistance, solvent resistance, heat resistance and heat storage of MEPCM. Finally, take the made MEPCM into spinning solution to prepare the thermo-regulated PAN fibers. It researched the effect of properties of fibers(which included breaking strength, elongation, loop strength, thermal shrinkage and boil water shrinkage and so on) by changing concentration of sodium thiocyanate, temperature of spinning solution and concentration of MEPCM in fibers in coagulation bath. Their thermal properties, heat resistance and form of fiber cross-section were characterized by SEM, DSC and TG.Results indicated that the average size of MEPCM was4.1μm by using instant emulsion instead of conventional emulsifiers and the MEPCM obtained good thermal regulating capacity. Considering the effect of the structure of monomer, MEPCM prepared by TMC and EDA as the shell material was best to prepare the thermo-regulated PAN fibers. With the increasing of coagulation bath concentration, the linear density of fibers increased, breaking strength and thermal shrinkage and boil water shrinkage decreased while elongation and loop strength first increased and then decreased. The best sodium thiocyanate concentration is10%in the coagulation bath. The linear density increased, breaking strength and loop strength decreased while elongation, thermal shrinkage and boil water shrinkage first increased and then decreased with the increasing of temperature of spinning solution. The most appropriate temperature of spinning solution was room temperature (about20℃) through the comparative study. As the concentration of MEPCM in the fibers increased, the linear density first decreased and then increased, breaking strength, thermal shrinkage, boil water shrinkage, elongation and loop strength decreased, enthalpy and thermo-regulated increased.