Synthesis Of Hydroxyl-terminated Polybutadiene Polyurethane Microcapsule With Phase Change Material Containing Keratin And Its Application

During the process of phase transition,phase change materials has the ability to regulate the temperature of the micro-environment.If we combine phase-change microcapsules with fibers and textiles,we can prepare new high-tech textiles that could regulate the micro-environment temperature in the fabric.In this study,phase-change microcapsules loaded with polyurethane as the shell and compound paraffin as the core are prepared.The microcapsules containing keratin were successfully synthetized through interfacial polymerization of hydroxyl-terminated polybutadiene(HTPB)and hexamethylene diisocyanate(HDI)with keratin as emulsifier.The average diameter,coating rate and yield of the phase-change microcapsules were used as evaluation indexes,the effects of the emulsifier dosage(relative to the total mass),the ratio of core to wall and the dosage of crosslinking agent(relative to the total mass)on the properties of microcapsules were explored.The optimized synthesis process of microcapsule is that the emulsifier dosage is 1.4%,the ratio of core material to wall material is 2.5:1,and the dosage of crosslinking agent is 0.24 %.The microcapsules at the optimal conditions are experimentally examined through laser particle sizer,scanning electron microscope(SEM),fourier transform infrared(FT-IR)tests,differential scanning calorimetry tests(DSC)and thermogravimetric(TG)tests.The experimental characterization show that the microcapsules distribute within the range of 1~15 ?m and show a normal distribution with an average particle size of 8 ?m.The SEM micrographs demonstrate that the deformable microcapsules have a regular spherical shape with good dispersion and no adhesion,and the microcapsules change from spherical to spindle shaped after extrusion.FT-IR spectra confirms that the microcapsules loaded with polyurethane as the shell and compound paraffin as the core contain proteins.DSC results indicate that the cover rate of the microcapsules is 46.45 % and the phase change enthalpy is 121.13 J/g.Additionally,the microcapsules exhibit good anti-permeability and excellent thermal stability under 30 heating and cooling cycles and could withstand heat up to 182?.Microcapsule finishing liquid was applied to the cotton fabrics through padding.The SEM micrographs demonstrate that the morphology of microcapsules remained intact and could be treated to the fabric surface through padding.Additionally,the finished cotton fabrics exhibited thermal controllable performance,their breaking strength and elongation at break in both warp and weft were improved,but their air permeability decreased by 18 %.