Preparation Of Graphene Oxide Copolymerization Modified Pet Fibers And Study On Theirs' Properities

Polyethylene terephthalate(PET)is a kind of polymer made by the polycondesation reaction of terephthalic acid(PTA)and ethylene glycol(EG),which owns excellent performance and have been widely used in packing and clothing,especially in the area of synthetics,which area PET accounts for 80%.Therefore,the development of functional PET fibers has attracted more and more attention.The traditional method of PET modification is introducing nano-particles like carbon nanotubes(CNT),silica and montmorilontie and other functional additives into basic materials.Graphene as a new materals with excellent mechanical properities and electrical conductivity and thermal conductivity which supply us some new ideas on development of functional PET fibers.The main research contents and conclusions of this project are as follows:1.According to the content of active groups and the particle size and thickness and some other elements to choose suitable graphene oxide(GO),and finally choose one with better overall performance.Then characterized it's structure and surface morphology.FTIR spectra show there are lots of oxygen functional groups.XPS and Raman spectra show that GO has more defects than graphite,that is,it contains rich reactive functional groups.XRD pattern show that the distance between the lamellar layers of purchased GO is pretty large that is the structure of graphene structure is loose which can be easily peel into a single layer.And the surface morphology and particle size distribution of GO were observed by SEM.The results shows GO particle size distribution is in a certain range about few microns.2.The preparation of graphene oxide-modified copolymerized PET by direct esterification of terephthalic acid(PTA)and ethylene glycol(EG)and third reaction monomer,graphene oxide(GO).We add GO in different stage of reaction,and adjust the ratio of GO addition include 0.1%,0.5%,1%,and 3%,respectively.Two series of graphene oxide modified copolymerized PET(GO-PET1 and GO-PET2).For study the chemical reaction of the GO and PET.We purified it(GO-PET)through ways of solution and centrifugation and resolution,recentrifugation and wash it,then get the GO which has been grafted PET chains,we named it P-GO-PET.The structure of P-GO-PET was characterized by FTIR,XPS,Raman and XRD.The results of FTIR and XPS indicate that the PET molecular chain was successfully grafted onto the graphene oxide sheet.Raman spectroscopy and dissolution experiments also reflected that the surface structure and solubility of GO changed after a certain degree of copolymerization,which can also prove PET molecular chain has been successfully introduced to the GO slice.The results of TGA and viscosity tests show that viscosity of GO-PET decreased with the increase of GO content,and series two's grafting rate higher than series one.Then we study the influence of GO to GO-PET,especially thermal properities and crystallinity properities through DSC,TGA and XRD.The study shows the thermal stability of GO-PET increase firstly and then decreased since the addition of GO.The results of XRD show that when GO is added,the crystallized nucleus density and crystallinity is increased,and the crystallinity is improved,while in series two when GO addition more than 1%,because of cross-linking reaction,crystallinity decreased.3.We choose three samples of Series 1,0.1%,0.5%,and 0.1% of Series 2 were melt spinning into fibers.3.2,3.5,and 3.8-fold drafts were performed for each sample.And study the degree of fiber orientation,boiling water shrinkage,mechanical and electrical and antibacterial properties.The results show that the degree of fiber orientation increases with the increase of the draw ratio of the fiber,but the degree of orientation of the GO-PET fiber is smaller than that of the pure PET;the boiling water shrinkage of the fiber increases with the augment of the draw ratio of the fiber,and the boiling water shrinkage of the graphene copolymerized modified PET fiber is lower than that of the pure PET;As a result,it was found that when the content of GO is small(0.1%),it has a reinforcing effect on pure PET,but the elongation at break and modulus of the GO-PET decreased,indicating that the modified PET(GO-PET)was improved in terms of flexibility;the conductivity study results showed that the resistance of the GO-PET fiber decreased which can be used in antistatic textile products;While research didn't shows there are obvious antibacterial properities.