Manufacture And Properties Of Melt-Spun Heat-storage And Thermo-regulated Fiber Containing Microencapsulated Phase Change Materials

Heat-storage and thermo-regulated textile is an active smart textile. It is manufactured by incorporating the low-temperature Phase Change Material (PCM) into the fiber or coating the PCM on the surface of the fabric. This novel comfortable textile is able to absorb, redistribute and release heat to prevent drastic changes in the wearer's head, body, hands and feet. If the circumstance temperature drops from the setting temperature, the PCM will change its state from liquid to solid, releasing heat and keeping the inner fabric in a higher temperature. Conversely, if the circumstance temperature rises from the setting temperature, the PCM will change its state from solid to liquid, absorbing the heat energy and keeping the fabric in a lower temperature. Thus the inner textile possesses a comfortable temperature by the PCM phase state changing. The manufacture, properties and applications of heat-storage and thermo-regulated textiles have been extensively studied since the 1980s, and these textiles were selected as one of the "21 inventions that will shape the 21st century" by the editorial staff of Newsday.It is an object to study the manufacture process and properties of melt-spun fiber containing microencapsulated phase-change materials (MicroPCMs) in the applied basic field. In this paper, the whole work was mainly divided into two parts: the research on the preparation of the MicroPCMs for incorporating into the fiber and the research on the manufacture process of melt-spun fiber containing MicroPCMs.The MicroPCMs with diameters below 5 micron were successfully synthesized by in-situ polymerization. Low-temperature paraffin wax was used as core material, and amino resin was used as shell material. The heat-resistant temperature of the MicroPCMs achieved 205 ℃, the PCM in the shell was permeable-proof and without super-cooling character. The structures and properties of the MicroPCMs were systematically studied by the applying of FTIR, SEM, GA, DSC and WAXD.The Heat-storage and thermo-regulated fibers were manufactured by melting spun process through using MicroPCMs as functional components, and polypropylene as fiber-forming material. The relationship between structure and properties of these fibers were systematically studied through using SEM, DSC, TGA, WAXD and SAXS etc. The following are the experimental results: 1. The amino resin is a suitable shell material for the encapsulating of paraffin wax.The mol ratio of the melamine/urea/formaldehyde is 3:1:12, the size of the MicroPCMs is even and with small impurity.2. The diameter of the MicroPCMs is below 5 micron. The microcapsules with the diameter of 1-2 micron possess the predominant according to the distribution on number basis, and the microcapsules with the diameter of 3 micron possess the predominant according to the distribution on volume basis. The microcapsules can be proper for melting spun process in respect of the size.3. The heat-resistant temperature of the MicroPCMs achieves 205 ℃, and the microcapsules can be proper for melting spun process in respect of the heat resistance.4. The content of the paraffin wax is about 75%(wt%), and the heat-storage ability of the MicroPCMs is about 180J/g.5. Using octadecane as PCM and octadecyl alcohol as anti-supercooling agent, the super-cooling of the MicroPCMs will be effectively restrained.6. The shell material of the MicroPCMs is amorphous phase, and the PCM in the microcapsules still has the strong crystallizing power.7. The heat-storage and thermo-regulated sheath/core composite fiber with different content of MicroPCMs were melting spun. The polypropylene chips were used as sheath component and the polyethylene containing 0-16%(wt%) MicroPCMs were used as core component. The spinning property of the fiber is favorable when the content of MicroPCMs is less than (or equal to) 12%, and it become poor when the content of MicroPCMs is equal to 16%.8. The titer of the fibers is lightly increasing and the tenacity is slowly decreasing with the content o...