Surface Modification and Characterization of PET Fibers

Improvement in synthetic fiber based composites is a hot topic in the material area.The incompatibility between the surfaces of synthetic fibers is a significant challenge due to fibers hydrophobic property.In this study,PET(polyethylene terephthalate) fibers based on low hydrophilic were slightly treated with NaOH or sodium dodecyl benzene sulfonate(SDBS).SEM images showed that there were some pits on the surface of PET fibers treated by NaOH,while PET fibers treated by SDBS became smoother.The peaks at 3725 cm^(-1) and 3628 cm^(-1) were generated for PET fibers treated by NaOH,which was attributed to—OH produced from the ester group hydrolysis,but no same peak is shown for the treated ones by SDBS.Meanwhile,the crystallinity indices of the treated PET fibers slightly decreased.Compared with original PET fibers,the formation of sheet made from PET fibers treated by NaOH became worse,but that from SDBS treated PET fibers became better.

Electrical and Optical Characterization of DBD and Its Application to Plasma Treatment of PET Fibers

A newly developed atmospheric pressure dielectric barrier discharge （DBD） plasma treatment system （PLA-PLA） was used in this study. The discharge is characterized by electrical analysis and optical emission spectroscopy （OES）. The characters of the discharge were found to change systematically with an increase of applied voltage and variation of flow ratio of O2/Ar in the plasma. The OES analysis revealed that the relatively weak spectrum line can be detected beyond a certain applied power value. It is also found that the emission intensity of main species in the discharge spectrum will be enhanced with the increase of applied power. To improve the wettability, poly （ethylene terephtalate） （PET） fiber was treated in this system. The surface morphology and properties of fiber after plasma treatment were investigated by both scanning electron microscope （SEM） and contact angle measurement.

Surface Modification of Polyethylene Terephthalate(PET) Fiber by Roll-to-Roll Treatment in Atmospheric Ar/O_2 Dielectric Barrier Discharge(DBD) Plasma

In this work,polyethylene terephthalate(PET) fibers were continuously treated by atmospheric dielectric barrier discharge(DBD) in Ar mixed O2 plasma,and the discharge was characterized by electrical function and optical diagnostics.It is found that the interfacial adhesion strength between treated PET fiber and resorcinol formaldehyde latex(RFL)(little)-rubber was improved(about 50%) by the measurement of interfacial shear strength(IFSS) and peel test.The wettability was improved rapidly in the initial treatment time.It is considered that oxidation chemical reaction as the major role of PET fiber surface modification is ahead of the physical etching effect.The high density of atomic oxygen in the plasma by optical emission spectroscopy supports the purpose.According to the scanning electron micrograph(SEM) image in the work,the longer treatment time obviously caused physical etching effect,which shall be less responsible for the improvement of the wettability.

Biodegradation of DTP and PET Fiber by Microbe

The degradation of diethylene glycol terephthalate (DTP) and polyethylene terephthalate (PET) fiber by microbe was studied.The degree of DTP degradation was determined by High Performance Liquid Chromatography (HPLC) to be more than 90%.The products after degradation of DTP and PET fiber were various.The degradation of DTP can be described by the first-order reaction model.The degradation of PET fiber was found to be little,but surface erosion of PET fiber could be clearly seen from the SEM photographs indicating there occurred some traces of biodegradation on the PET fiber surface.

STUDY ON THE MICROSTRUCTURE AND PROPERTY OF PET FIBER BY LASER RAMAN MICROSCOPE

In this paper, the microstructure change of one step-draw PET fiber has been studied byvarious methods, such as, Laser Raman Microscope, Wide-angle X-ray, Density-gradient andPolarizing Microscope. The computer has been used to resolve overlapped bands in the Ramanspectra. Then the band changes have been correlated with trans, gauche and stressed trans-conformations indicated by a conformational index. Based on these indices, the relationshipbetween the conformation change of glycol units in the fiber structure and the macromechanicalproperties of fiber is expounded.

RELATION BETWEEN DYNAMIC LOSS MODULUS AND DIFFUSION COEFFICIENT IN A MODIFIED PET FIBER

The mobility of polymer chain segments is shown to play a major role in the diffusion ofdisperse dyes in a copolymerization modified PET system, monoepoxy compoundCH_3 (CH_3),OCH_2CH--CH_2 modified PET. The rate of dye diffusion (diffusion coefficient D) hasbeen related to the time-dependent mechanical property, dynamic loss modulus E', which iscontrolled by the mobility of chain segments. In this modified copolyester system, the variance ofamount of modifier in the copolyester fibers causes the change in disperse dye diffusion coefficientto fiber, and in the dynamic loss modulus of the fibers, but the relationship between the diffusionand the dynamic loss modulus is in agreement with the theoretical relation derived by Bell andDumbleton. The relation obtained in this paper is:Ln D=-2. 28Ln E'+26. 81

Hydrolysis-resistant Polyethylene Terephthalate (PET) Fiber

For certain industrial applications, the mechanical properties of PET fiber can be deteriorated from hydrolysis because the terminal carboxylic groups promote the degradation of macromolecules under high moisture and high temperature. It limits the wide applications of PET fiber in some special cases. In this paper, three additives are selected to improve the hydrolytic stability through the reaction of bi-functional groups on additive molecules with carboxyl groups on PET molecules. The additives can serve not only as hydrolysis stabilizers, but also as agents to increase the molecular weight and consequently to improve PET fiber mechanical properties. PET pellets were blended with additive before spinning, and melt spun into fiber. The fibers were then hydrolyzed in an autoclave by saturated vapor at 140℃ for a period of time. Measurements of intrinsic viscosity, terminal carboxylic group value and strength of polyester fibers were carried out to study the effects of hydrolysis resistance. Results show that 2,2′-bis(2-oxazoline) has best hydrolysis-resistibility and the chain-extension effect at the same time.

Synthesis and characterization of azo dyestuff based on bis(2-hydroxyethyl) terephthalate derived from depolymerized waste poly(ethylene terephthalate) fibers

This work aimed at effectively utilizing the chemically depolymerized waste poly（ethylene terephthalate）（PET） fibers into useful products for the textile industry.PET fibers were glycolytically degraded by excess ethylene glycol as depolymerizing agent and zinc acetate dihydrate as catalyst.The glycolysis product,bis（2-hydroxyethyl） terephthalate（BHET）,was purified through repeated crystallization to get an average yield above 80%.Then,BHET was nitrated,reduced,and azotized to get diazonium salt.Finally,the produced diazonium salt was coupled with 1-（4-sulfophenyl）-3-methyl-5-pyrazolone to get azo dyestuff.The structures of BHET and azo dyestuff were identified by FT1 R and ^1H NMR spectra and elemental analysis.Nylon filaments dyed by the synthesized azo dyestuff with the dye bath pH from 4.14 to 5.88 showed bright yellow color.The performances of the dyestuff were described with dye uptake,color fastness,K/S,L^＊,a^＊,b^＊.and △E^＊ values.