阳离子改性共聚酯纤维结构与性能的研究

Study on structures and properties of cationic modification copolyester fiber

采用常规力学测试、X光衍射、DMA、DSC及SEM对高温高压型阳离子染料可染共聚酯(CDP)及常温沸染型阳离子染料可染共聚酯(ECDP)纤维的结构及性能进行系统研究,并与常规PET纤维做比较.结果表明:与PET相比,CDP及ECDP纤维的初始模量下降,断裂伸长率增加,并且纤维的衍射峰位置未发生变化,改性共聚酯的组分存在于无定形区.从DMA谱图中发现,与PET相似,CDP及ECDP初生纤维也存在两个α内耗峰,并且在后续加工过程中,其Tg(L)峰钝化、消失,而Tg(U)峰温、峰宽进一步降低;其中,ECDP纤维的Tg较低,(tanδ)max较高,更有利于提高纤维的上染率.在DSC谱图中,CDP及ECDP成品纤维的熔程较宽,熔点及结晶度均小于常规PET纤维.SEM观察发现,无油ECDP纤维的表面较PET纤维粗糙,说明第三及第四单体的加入对纤维表面造成了一定影响,需使用ECDP专用油剂才可保证纤维生产的顺利进行.

The structures and properties of cationic dyeable poly（ethylene terephthalate）（CDP）and easy cationic dyeable poly（ethylene terephthalate）（ECDP）are investigated by mechanical test,X-ray diffraction,DMA,DSC and SEM.The results show thatc：ompared with PET fiber,initial modulus of CDP and ECDP fiber decrease and the elongation at break increase.The position of X-ray diffraction peak of CDP and ECDP are the same as which of PET,the composition of copolyester didn′t change the original PET unit cell and they gathered in the amorphous regions.The DMA indicates that there are two α peaks in CDP and ECDP initial fibers which are similar to PET initial fiber.The Tg（L）peak which located in lower temperature disappears gradually,and there is a further reduction in peak width and temperature for Tg（U）peak during the follow-up process.In addtion,Tg of ECDP fibers is lower and the（tan δ）max is higher so that it could contribute to improve dye-uptake of fiber.The DSC suggested that the range of melting of CDP and ECDP finished fiber are wide,and the melting point and crystallinity are less than which of PET fiber.The surface of ECDP staple fiber without finish are rough shows that the surface of fiber are caused by the addition of third and fourth monomers.So the ECDP special finishes must be used to ensure smooth processes in the manufacture of the fiber.