Study On Structure And Properties Of Heat-resisting Spandex Fiber

Spandex fiber as a kind of high elongation and highresilience of the fiber material,which is widely used in daily.In this paper,the heat-resistant spandex fibers refer to South Korea Hyosung spandex and Du Pont Invista spandex.By a series of analysis and testing methods,the structure and properties of the two kinds of heat-resisting spandex fiber are studied.Meanwhile,whichare compared with domestic spandex fiber,mainly including the structure,basic properties,mechanical properties,thermal properties and high temperature dyeing properties.The results show that:?1?The crystallinity of Heat-resisting spandex fiber macromolecule is higher,the crystal area distribution is regular and better than domestic spandex fiber,but its orientation degree is lower than domestic spandex fiber;According to the IR spectrum of heat-resistant spandex fiber shows its macromolecule chain amino,free carbonyl,hydrogen bond carbonyl are all enhanced and shifted to low wavenumber;The number average molecular weight of the heat-resistant spandex fibers is higher and the relative molecular mass distribution index is also narrower.?2?Heat-resisting spandex fiber density,linear density are slightly smaller,from the electron microscopy can be seen in the surface of the heat-resistant Invista spandex fiber without grooves,the lowest moisture regain,and the measured wettability is the worst phase consistent;but another heat-resistant Hyosung spandex fiber surfaceroughness with holesissimilar to domestic spandex fiber surface morphology.?3?The initial modulus and breaking strength of heat-resistant Invista spandex fiber are high,but its elongation at break is the smallest,while heat-resistant Hyosung spandex fiberis the lowest breaking strength and low elongation at break.Both the dry heat treatment and the wet heat treatment increase the breaking strength and the elongation at break of heat-resistant spandex fiber and domestic spandex fiber.?4?Heat-resistant Hyosung spandex fiber and heat-resistant Invista spandex fiber have good thermal stability.The initial decomposition temperature is about 260?,which is higher than domestic spandex fiber at 30?,also the maximum temperature of DTG is higher than domestic spandex fiber,especially for the first time above 10?or so;the DSC curves show that heat-resistant Hyosung spandex fiber and heat-resistant Invista spandex fiber when heated to 200?,they are soften and appear cracking exothermic peak,when heated to 310?,they appear endothermic peak of oxidation crosslinking,meanwhile the Hyosung spandex softening temperature and melt temperature are higher than others.?5?Under the high temperature dyeing,the dyeing rate of heat-resistant Invista spandex fiber is the lowest,after soaping the color fastness of Invista spandex fiberonly is up to level 3,but in the staining scale of three spandex fibers performance are consistent,only cotton and acrylic can meet the requirements.The crystallinity and orientation degree of heat-resistant spandex fiber and domestic spandex fiber are decreased after dyeing,but heat-resistant spandex fiber loss is lower than domestic spandex;while the originalpeak at2939cm^-1 of heat-resistantspandex fiber shifts to low wavenumber 2918cm^-1 and intensity is bigger.At the same time,dyeing decreases the breaking strength of three kinds of spandex fiber,among which domestic spandex isdecreased most;but elongation at breakis increased,and the increase rate of heat-resistant spandexisthe highest.The researchon heat-resistant spandex fiber is based on the main performance in the current application of spandex fiber.It can provide theoretical reference forfuture self-dependent research and development of heat-resistant spandex fiber and guide the improvement project of heat-resistant spandex fiber.