Study On Oligomers Problem During Dyeing And Processing Polyester Textile Material

There has been a problem that frequently causes concern among the wet processors, viz. the control and elimination of oligomers in the processing of polyester fiber. So far, there are many studies about auxiliaries that can be used in the dyebath or aftertreatment to overcome oligomers problems. However, even with substantial negative effects on cost, environment, and quality of the dyed goods, no method currently available can effectively eliminate the influence of oligomers on processing after dyeing, especially for superfine fiber. In fact, it is the key for resolving oligomers problem to extract oligomers, although there is less study about that, especially in China.In this paper, the conventional oligomers extracting measure was improved through researching the resolvability of oligomers. Oligomers were extracted effectively through ultrasonic extraction with compound solvent (dioxane/chloroform), whose solubility parameter is near to that of oligomers. Compared with conventional extraction measure, ultrasonic extraction had many advantages such as shorter extraction time and less solvent.The content of surface oligomers, which are the most important facts causing problems for dyeing, was measured through standard ultraviolet absorption curve and its veracity was also assessed.The properties of oligomers were studied through thin-layer chromatogram, JSM-5600LD Scanning Electron JEOL, microscope differential scanning calorimeter, wide angle X radial diffraction, viscosity meter, infrared spectrophotometer ultraviolet spectrophotometer, ultrasonic instrument, laser granularity analyzing instrument and so on. The results revealed the effecting regulation of different facts on the content, crystallization, diffusibility and resolvability of oligomers and proved that the oligomers are compounds including mainly cyclic trimer, which tend to congregate and crystallize. The tremendous effects of solvent vapor and ultrasound wave on the surface oligomers were found for the first time and wet heat-treatment could promote themigration of oligomers more rapidly than dry heat-treatment and nonionic surfactant could decrease the content of surface oligomers to some extent. The practicability of reducing the content of surface oligomers before dyeing was also proved. Above studies could help explaining the phenomenon emergencing in practical producing and afford important guidance for resolving them.On base of above studies, the effects of the technology and auxiliaries on the content of surface oligomers were studied systemically in order to attain effective methods for decreasing the content of surface oligomers. The cooperation effect of different auxiliaries was also studied and a kind of multiplex oligomers remover ZS3 were obtained and the optimal dyeing technology for reducing oligomers was obtained on traditional dyeing instrument. What's more, a new technology, viz Ultrasonic / Alkali System, was put forward and the technology was optimized. At the same time the effect of Ultrasonic / Alkali System on physics properties and dyeing properties were accessed. The result showed that Ultrasonic / Alkali System could decrease remarkably surface oligomers content of polyester fiber dyed by HIP without side effect for fiber dyeing properties.In this paper, a kind of new-style oligomers removers PECE were contrived and synthesized according to the characteristics of oligomers, which were a kind of complex including hindered polyalcohol esters with one ester radical, two ester radicals or three esters radicals, which could not penetrate the fiber easily but could promote the resolvability and diffusibility of oligomers in solution. At first, the middle product TMH was synthesized according to Cannizzaro and the technology was optimized, and the product TMH was identified through IR, .1HNMR, MS. Then a series of esters PECE (1-5) were synthesized by choosing a kind of special catalyst -carried phosphotungstic acid, with TMH and PEC as raw materials. The effects of PECE (1) and its multiplex auxiliaries on the granu...