Study On Controllable Flame Retardant Modification Of PAN Fiber/fabric UV Grafting

The new century,textiles have been infiltrated into many fields of people's life.And the safety performance of textiles,especially the safety problems of textile fire caused by burning,has attracted more and more people's attention in the world.With the concept of "people-oriented" steadily and deeply accepted in the hearts of the people,it is imperative to vigorously develop non-toxic,low smoke,halogen-free flame retardant textiles.Polyacrylonitrile(PAN)fiber,commonly known as acrylic,is one of the world's three major synthetic fibers,with the reputation of "artificial wool".PAN fiber has been widely used in clothing,decoration and industrial fields due to its excellent soft,fluffy and light-resistant.However,the limit oxygen index(LOI)of PAN fiber is about 18%,that is,it is flammable fiber,which largely limits the promotion of PAN fiber in textile industry.At present,our country's research on is still in the exploratory stage,and so it is necessary to further explore the flame-retardant modification of PAN fiber for large-scale production.In the first part of the study,the PAN-g-HEMA fiber/fabric was manufactured by one-step UV induced photografting.in which PAN fiber/fabric as matrix,acetone as solvent,benzophenone(BP)as the initiator,and hydroxyethyl methacrylate(HEMA),as the grafting monomer,introducing the active group hydroxyl(-OH)into the macromolecular chain.At the same time,the effects of monomer concentration,initiator concentration,reaction temperature,illumination distance and illumination time on the grafting rate were discussed.Combined with a number of indicators,the 53%grafted samples were chosen for the next step treatment and the optimum process was determined.The structure and properties of PAN fiber/fabric with different grafting rate were characterized by many analytical means,including infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),Differential Scanning Calorimetry(DSC),thermal gravimetric(TG-DTG)and scanning electron microscopy(SEM).In the second part of the study,PAN-g-53%HEMA fiber/fabric was reacted with phosphoric acid and urea through chemical modification method,successfully introducing flame-retardant phosphorus and nitrogen into the grafting chain,making the flame-retardant polyacrylonitrile(FR-PAN)fiber/fabric.The structure and properties of PAN fiber/fabric with different stages were analyzed by infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction (XRD).Differential Scanning Calorimetry(DSC),thermal gravimetric(TG-DTG).scanning electron microscopy(SEM),limiting oxygen index(LOI)and so on.The results indicated that the FR-PAN fiber/fabric has a good flame retardant effect and is co-flame retardant in the condensed phase and in the gas phase.Comprehensively,a novel approach for preparing the flame-retardant PAN fiber/fabric is developed in the paper,by combining one-step UV induced photografting and chemical methods,achieving the aim of controlling flame retardant modification on the PAN fiber/fabric surface.