Preparation By Functional Luminous Polyester Fibers By In-situ Polymerization

Luminous polyester fiber is a novel fiber with luminescent function, which is made ofluminous powder and fiber-forming polymer as the main raw materials. It has been widely usedin many fields such as transportation, night work, fire emergency, textiles, etc.However, the commercially available products have some disadvantages such as lowluminous intensity and tenacity. It is mainly because the degradation of polymer would happenwhen the composites should suffer twice heating process such as masterbatch preparation andmelt spinning, in addition, the high content and large particle size of luminous materials maycause the poor spinnability. In this paper, based on the dispersion stability of luminous powdersin ethylene glycol (EG), PET-based luminous functional composites with high inherent viscosityand good dispersibility were prepared by in-situ polymerization. Thus, the problems such asdispersion of powder in PET matrix and the degradation could be solved, the spinnability andluminous properties were improved. In order to improve the mechanical and post processingperformance, a composite spinning method was employed. The detailed research content andconclusions are summarized as follow:1. The dispersion process of luminous powders. Ball-milling method was applied toinvestigate the dispersion of luminous powders in EG. The effects of milling time, differentdispersants and dispersant contents on dispersion stability were studied and a best dispersionprocess was obtained. We chose FCY (2%wt) as dispersing agent and milling time was2h.2. The process conditions of in-situ polymerization. In this paper, PET-based luminousfunctional composites were prepared by in-situ polymerization. The effects of powder contents, polymerization condition and discharge powers on inherent viscosities were investigated. Theresults indicated that the post-esterification-adding of luminous powders could promote thepolymerization procedures and the molecular weight was slightly by elevating the dischargepower. The PET-based luminous functional composites with luminous powder contents of5,8and12wt%were prepared. The inherent viscosities of obtained composite chips were all above0.64dL/g, which can meet the requirement of the following spinning process. Scanning electronmicroscope images showed that PET-based luminous functional composites were prepared byin-situ polymerization had better particle dispersion than those by conventional blending method.3. Thermal properties of the PET-based luminous functional composites. The crystallizationbehavior of the composites was studied by differential scanning calorimeter (DSC). It was foundthat the cold-crystallization temperature decreased with increasing of luminous powder content,while the thermal-crystallization temperature increased. The thermal degradation of compositeswere studied by thermo gravimetric (TG) under nitrogen atmosphere, the results showed that thepresence of luminous powder barely affect the decomposition behavior of PET matrix at hightemperature. The thermal oxidative degradation of composites were studied using amicro-blender. The results indicated that inherent viscosities decreased with increasing ofluminous powder content, thermal treatment time and temperature. Moreover, the viscositysharply decreased with elevating temperature, so a lower processing temperature should beapplied.4. Structure and properties of luminous composite fibers; The luminous composite fiberswere prepared by melt composite spinning, The FTIR results showed that luminous powder didnot change the chemical structure of PET fibers, but the breaking strength and elongation ofcomposite fibers were reduced. The luminescent test indicated that the afterglow time increasedwith increasing luminous powder content. Mechanical properties and surface finish of skin-corecomposite fibers were better than that of the common luminous fibers, thus benefited the postprocessing, but the afterglow time slightly decreased. The breaking strength of the compositefiber achieved2.8cN/dtex and afterglow time was6h when the luminous fibers (luminouspowders of8%) content was88%.