Carrier-Free and Low-Temperature Ultradeep Dyeing ofPoly(ethylene terephthalate) Copolyester Modified with Sodium-5-sulfo-bis(hydroxyethyl)-isophthalate and 2‑Methyl-1,3-propanediolJun Wang,† Xiaoyan Li,† Fengyan Ge,† Zaisheng Cai,*,† and Lixia Gu‡
†Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, Donghua University, North Renmin Road 2999,Shanghai 201620, China‡State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering,Donghua University, North Renmin Road 2999, Shanghai 201620, China
*S Supporting Information
ABSTRACT: To obtain sufficient dyeability, dyeing of poly(ethylene terephthalate)fabrics must be performed at high temperature and high pressure or by using a no-eco-friendly carrier at atmospheric pressure, which implies large energy consumptionand environmental contamination. In order to improve the sustainability of thedyeing process, a carrier-free and low-temperature dyeing procedure was developedfor the poly(ethylene terephthalate) copolyester (MCDP) incorporated withsodium-5-sulfo-bis(hydroxyethyl)-isophthalate (SIP) and 2-methyl-1,3-propanediol(MPD). The results obtained from cationic dyeing at optimized conditions show anoutstanding dye utilization (99.0%) with MCDP, which is much higher than that ofthe conventional SIP-modified copolyester. Meanwhile, the introduction of SIP andMPD contents ensures the large adsorption and fast diffusion of dye molecules intothe amorphous region of fibers, allowing an efficient and deep disperse dyeing ofpolyester fabrics under atmosphere in the absence of carriers. The environmentalbenefits arising from high quality dyed MCDP fabrics with ultradeep dyeing performance and excellent color fastness through afacile and clean dyeing process are highlighted with the economic ones.
Of all synthetic fibers, poly(ethylene terephthalate) (PET)fibers have been widely used in the textile industry due to theirunique physical and mechanical properties. However, dyeing ofPET fabrics with various dyes is an intricate matter andpresents considerable difficulties because of their highcrystallinity, tight structure, and lack of reactive groups.1 Toobtain sufficient dyeability, general dyeing conditions used forPET fabrics require high temperatures (around 130 °C) andhigh pressures, which imply large energy consumption andpotential risk caused by pressurized vessels.1,2
Carrier dyeing of polyester has been intensively studied as ameans of improving dye uptake and lowering disperse dyeingtemperature.3,4 The presence of carrier can make the fiberundergo some structural transformations which facilitated thedye adsorption and diffusion.5,6 Nevertheless, most of thecarriers (phenols, amines, etc.) have significant problems withtoxicity and environmental contamination; thus, much effort isrequired to develop new eco-friendly and low-temperaturedyeing of PET without the need for carriers.7−9
Easy cationic dyeable copolyester (ECDP)10−13 is known fora modified PET copolyester dyeing at boiling temperatureunder atmospheric pressure without carriers. It has beenproduced by incorporating sodium-5-sulfo-bis(hydroxyethyl)-
isophthalate (SIP) and poly(ethylene glycol) (PEG) intoregular polyester. Compared to the normal SIP-incorporatedcopolyester13−16 (known as cationic dyeable copolyester,CDP), ECDP shows improved boiling dyeability and enhancedhygroscopicity thanks to the increase of ether bond andhydroxyl value from PEG units. However, the furtherapplication of ECDP as PET replacement has been limitedby the undesired properties, such as poor spinnability, low lightfastness, and poor pile-on property in the boiling dyeingprocesses.15,17
Recently, a 2-methyl-1,3-propanediol (MPD) modifiedcopolyester (MCDP) was developed in our laboratory toovercome the drawbacks of ECDP and further enhance itsdyeability at boiling temperature.18,19 MCDP fiber wassynthesized and prepared using SIP and MPD as the thirdand fourth comonomers by a melting and drawing process. Thenewly produced copolyester displayed high quality properties ofsoft handle, antipilling property, and excellent spinnability anddrawability. Most importantly, the introduction of MPDsubstantially reduced the regularity of SIP-modified PET and
Received: February 17, 2016Revised: May 4, 2016Published: May 6, 2016
increased the accessibility for the dye molecule, offering thepossibility for ultradeep dyeing under atmospheric conditionswithout carriers.In the present work, a carrier-free and low-temperature
dyeing procedure for MCDP was developed. The influence ofdyeing conditions (pH, temperature, time, and dye concen-tration) on cationic and disperse dyeability of MCDP fabricswas elucidated. The dye performance including color strength(K/S value), tensile strength, and the color fastness of MCDPwas measured and compared with regulator PET and SIP-modified PET fabrics. Moreover, the structure and thermalproperty of the MCDP fabric was also evaluated to analyze thedyeing mechanism and dyeability of the fabric with cationic anddisperse dyes.
■ MATERIALS AND METHODSMaterials. The preparation of CDP, ECDP, and MCDP
copolyester containing identical SIP content was mentioned in theprevious work.18,19 PET, CDP, ECDP, and MCDP woven fabricsinvestigated (plain weave, 110 g/cm3) were supplied by ShanghaiLianji Synthetic Fiber Co., Ltd. (China). All fabrics were soaped at 60°C for 30 min and air-dried at room temperature. Four commercialcationic and disperse dyes were supplied by Runtu Co., Ltd. (China)with the chemical structures shown in Figure 1. Chemical reagents
including acetic acid, sodium acetate, sodium dihydrogen phosphate,sodium hydrogen phosphate, citric acid, sodium carbonate, andsodium hydrosulfite were of analytical grade and were used as receivedfrom Sinopharm Chemical Reagent Co. Ltd. (China).
Dyeing Procedures. For cationic dyeing, CDP, ECDP, andMCDP fabrics weighing 1.0 g were dyed in a dyeing machine (Rapid;Taiwan) with Basic Red 46 at various pH values (3−8) and dyeconcentrations (1−8% o.w.f). The liquor ratio was kept at 20:1.Dyeing temperature was raised from 40 to 70 °C by 1 °C/min andheld for 10 min, and then was up to 100 °C for a fixed time. Afterdyeing, the fabrics were washed at 40 °C for 30 min and dried underambient conditions.
For disperse dyeing, MCDP fabric samples weighing 1.0 g weredyed with three disperse dyes at various dyebath conditions (pH, time,temperature and dye concentration). The liquor ratio was kept at 20:1,the temperature was set at 40 °C, and then raised to a fixedtemperature by 1 °C/min and dyeing operations continued for a fixedtime. After dyeing, the dyed fabrics were washed twice and air-dried.The alkaline pretreatment and conventional disperse dyeing of PETfabrics was carried out under high temperature and high pressure(HTHP) conditions as described before.20
Measurements. The detailed procedures for dye uptake, coloryield, color fastness, and tensile strength test are provided in theSupporting Information.
Differential Scanning Calorimetry (DSC). The thermal property ofthe CDP, ECDP, and MCDP fabric was measured using ThermalAnalyzer 204F1 (Netzsch, German) under nitrogen atmosphere. Thefollowing conditions were used: temperature range, 30−290 °C; scanrate, 10 °C/min; differential thermal compensation range, 120 mW;and sampling temperature, 50−270 °C.
X-ray Diffraction (XRD). The XRD analysis were performed on X-ray diffractometer D/Max 2500PC (Rigaku, Japan). The diffractedintensity of Cu Kα radiation (0.154 nm, 40 kV, and 200 mA) wasmeasured in the 2θ range between 5° and 60° at the scanning rate of 5°C/min.
■ RESULTS AND DISCUSSIONThermal and Structural Property. DSC heating curves
for CDP, ECDP, and MCDP fabrics in Figure 2a distinctlyexhibit the region of glass transition and peaks correspondingto cold crystallization and melting behavior. It can be observedthat the glass transition temperature (Tg) decreased in theorder of CDP, ECDP, and MCDP. This manifests that thebranched methyl groups in the MPD unit enhanced flexibilityand the irregularity of molecular chains, meaning that MCDPhas more free volume and larger fraction of amorphous regionswhich allowed more dye molecules to penetrate. Accordingly,the lower Tg these samples have, the better were the dyeabilityand soft handling with which they were endowed.Meanwhile, the incorporation of feed MPD as the fourth
component in the PET structure result in random copolyesterwith considerable enhancement in chain flexibility. This
Figure 1. Chemical structure of used cationic and disperse dyes.
Figure 2. DSC thermograms and WRD diffractograms of all SIP-modified copolyesters.
ACS Sustainable Chemistry & Engineering Research Article
enhanced the capability of molecular chains crowding intocrystal lattices, leading to a reduction of cold crystallizationtemperature (Tcc) of MCDP compared with other SIP-modifiedPET.11,21 Another reason for this phenomenon is that sodiumcompounds could nucleate the crystallization of PET. Theaddition of the MPD unit made more ionic species available tothe reaction with the ester linkage of PET, creating sodiumcarboxylate chain ends, which were concluded to be theeffective nucleating species.22
Another thermal parameter, the melting temperature (Tm),was found to decrease in the order of MCDP, CDP, and ECDP,accompanying with the gradually widening melting peak. Asreported elsewhere,11,17,23 the presence of unstable ether bondsin PEG segments led to the poor thermal stability of ECDP.However, MCDP with higher thermal stability is due to theadverse effect of the methyl side groups on chain segmentmotion, resulting in the improved thermal stability to somedegree.The X-ray diffraction pattern of a polymer reflects its
crystalline structure. In Figure 2b, there is no obvious positionalchanges except for the diffraction intensities of the character-istic diffraction peaks in the XRD spectra, indicating that theadded MPD and PEG units were in the noncrystalline state asminor components in these copolyesters. This can be provenby the almost unchanged diffracting angles of (010), (110), and(100) reflecting planes, which are 17.5°, 22.5°, and 25.8° for alltesting samples. In addition, the crystallinities of the CDP,ECDP, and MCDP calculated by the method of dividing
peaks24 were 48.6, 43.9, and 39.1%, respectively. As mentionedearlier, the crystallinity of MCDP is the lowest due to the sterichindrance effect of the MPD groups destroying the regularity ofthe polymer chain molecules and leading to a looser crystalstructure.
Cationic Dyeability. The presence of SIP contentincreased anionic dye sites for cationic dye−fiber interaction,imparting the PET copolyester with cationic dyeability. Ourfirst objective is to evaluate the cationic dyeability of MCDPfiber for all cationic dyeable copolyesters with identical SIPcontent. Therefore, the dyeing behavior of cationic dye onCDP, ECDP, and MCDP fabrics was investigated with respectto pH, time, temperature, and dye dosage.
pH. Figure 3a presents the effect of pH on dye uptakes of allSIP-modified PET fabrics. Irrespective of the type ofcopolyesters, the dye uptakes of Basic Red 46 (BR46) increasedas pH increased and reached a maximum in the region of pH4−5. This result can be attributed to the hydrolytic stability ofthe dye structure and the surface charge of copolyester fiber at acertain pH.25 The dye uptake at maximum can be explained bythe increased probability of interactions between the ionizedsulfonic groups on fiber and protonated dye molecules, as wellas the stability of cationic dye at the appropriate pH.26
Temperature. Generally, the dye uptake in synthetic fiberwas correlated with the quantity and structure of theamorphous region. It can be found from Figure 3b that thedye exhaustion increased markedly when holding temperatureexceeded the Tg of three copolyester fiber. This trend could be
Figure 3. Effects of (a) pH (b) temperature, (c) time, and (d) dye concentration on the cationic dyeability of all SIP-modified copolyesters. Dyeingconditions: (a) 5% o.w.f, 100 °C, 130 min; (b) pH 4−5, 5% o.w.f, 130 min; (c) pH 4−5, 5% o.w.f, 100 °C; and (d) pH 4−5, 100 °C, 130 min.
ACS Sustainable Chemistry & Engineering Research Article
explained by the increased molecular movements of the fibersegment at temperatures higher than Tg, and the consequentgeneration of more free volume allowed dyes to penetrate(Scheme 1).The highest color yield of MCDP shows that the decreased
crystallinity of the copolyester is caused by the introduction offlexible branched diol into the macromolecular chain. Withdecreasing crystallinity, the amorphous regions and theaccessibility into them increased. Accordingly, the dye uptakecapacity of the MPD-modified copolyester improved because oftrapping more dye molecules within them.Time. The dyeing rate curve in Figure 3c reveals that a
marked increase in the percent exhaustion of all dyed samplesoccurred at a temperature about 10 °C higher than their Tgs(ca. 50 min). This can be explained in terms of the promotedrate of dye diffusion as a consequence of the formation ofamorphous region transformed from partial crystalline. Incomparison with other copolyester, MCDP exhibited theshorter balance time (ca. 100 min) and higher dyeing capacitydue to its larger quantity of available dyeing sites. That is to say,for MCDP, a smaller amount of dyestuff is needed for the sameshade depth.Dye Concentration. Figure 3d shows that the extent of dye
exhaustion decreased progressively, regardless of fiber type,with increasing dye concentration in the dyebath. This trend isdue to the increased adsorption of dye cations on negativelycharged fiber surface which weaken the electrostatic dye−fiberinteraction and prevent dye sorption.27 Furthermore, theavailable dye sites on fiber were gradually occupied, and thecompetitive hydrolysis of dye molecules increased at higher dyeconcentrations, resulting in a decrease of dye uptake.28
To further investigate the dye adsorption capacity of MCDP,dye saturation value, which corresponds to the ability of anionicsynthetic fiber to absorb cationic dye, was calculated by a three-point fitting method (Figure S1−S3 of the SupportingInformation).29 Interestingly, the MCDP fiber (2.84%) showedmuch higher value for dye saturation compared to that of CDP(0.49%) and ECDP (1.96%) fibers with identical feed SIPcontents. The higher dye saturation value of the MCDP can beexplained by its relatively more open structure and increasedaccessibility of the sulfonic groups in the fiber.
Disperse Dyeability. One of our attempts in this study wasto evaluate the quality of dyed MCDP fabrics with dispersedyes at boiling temperature under atmospheric conditionswithout carriers. Dyeing experiments with three dispersedyestuffs might contribute to the exploration of the dyeabilityof MCDP under these dyeing conditions.
pH. It is shown in Figure 4a that the color strength of theMCDP fabrics improved when the pH values increased from 3to 6 but started to gradually decline with further increase.Similar to cationic dye, the effect of disperse dyebath pH can beattributed to the correlation between the intention of hydrolysisand reduction of disperse dyes and the quantity and structure ofamorphous regions for the MCDP fiber structure.30 Results ofthe experiment indicate an optimal dye yield at pH 5−6.
Temperature. It can be observed in Figure 4b that the colorstrength of dyed MCDP increases at first and then decreaseswith increasing temperature. Generally, a higher temperaturecould could promote the thermal movement of the dyemolecules by breaking the bonds (van der Waals forces,Dipole−dipole bond and hydrogen bond) between polymerchains above Tg.
31 Higher color yield obtained with theformation of larger, more accessible voids through which the
Scheme 1. Illustration for the Penetration of MCDP Copolyester and Possible Interactions between the Copolyester andCationic/Disperse Dye Molecules
ACS Sustainable Chemistry & Engineering Research Article
disperse dye molecules can diffuse more readily. However, astemperature was increased successively, the tendency of the dyemolecules to go from the fiber into the dyebath was alsoenhanced.Time and Dye Concentration. Figure 4c shows that there is
almost no dye adsorption below 65 °C. A holding time of 30min at 100 °C should be sufficient based on the equilibriumpoint detected. This behavior is a consequence of the balance inthe amounts of dyestuff that diffused into the fibers and escapedfrom fibers at equilibrium. The dye uptake of BR46 was plottedas a function of dye concentrations in Figure 2d. It was seenthat the dye uptake changed little when the dye concentrationup to 5% o.w.f. This trend may be caused by the crash andcoagulation of dyestuff molecules at high concentration, whichreduce the adsorption and fixation of disperse dye on MCDPfabrics.30
Comparison of Conventional Dyeing Process. Thecolor strength data above indicated that MCDP fabric could besuccessfully dyed with disperse dyes in the absence of a carrier.To further evaluate the possibility of the replacement of HTHPdyeing of PET, the K/S values of three disperse dyes on all SIP-modified copolyesters at boiling temperature and conventionaldyed PET were measured in Figure 5.As expected, for all disperse dyes, it can be seen MCDP
fabrics yield the highest K/S values in modified copolyester,which corresponded well to their cationic dyeability. Therefore,it seemed that changes in the amorphous structure caused bythe additional MPD content played a great role not only incationic dye adsorption but also in disperse dye diffusion.
Compared to conventional dyeing of PET, the K/S values ofthe MCDP copolyester was 19.6−35.5% higher than that ofdyed PET. Especially, the low-temperature dyeing methodproduced ultradeep dyed products without the alkali pretreat-ment of PET and the addition of carrier. This is very importantbecause the use of alkali pretreatment and carrier would resultin the difficulty of effluent treatment.
Figure 4. Effects of (a) pH, (b) temperature, (c) time, and (d) dye concentration on dye uptake of three different azo disperse dyes on MCDPcopolyesters. Dyeing conditions: (a) 4% o.w.f, 100 °C, 90 min; (b) pH 5−6, 4% o.w.f, 90 min; (c) pH 5−6, 4% o.w.f, 100 °C; and (d) pH 5−6, 100°C, 90 min.
Figure 5. Comparison of color strength between HTHP-dyed PETfabrics and SIP-modified copolyester fabrics dyed at 100 °C with 5%o.w.f disperse dyes.
ACS Sustainable Chemistry & Engineering Research Article
The ultradeep color yield can be interpreted by the dyeingmechanism of MCDP shown in Scheme 1. In this work,Disperse Yellow 163 (DY163), Disperse Red 167 (DR167),and Disperse Blue 79 (DB79) are azo dyes and can be adsorbedon the surface of MCDP fibers by van der Waals force andhydrogen bonding. Similar to the dyeing mechanism of PET,initial adsorption is rapid because of the high affinity polyesterhas for disperse dyes, but diffusion within the fiber is the keystage of whole dyeing as it is at the slowest rate. For the dyeingof MCDP, the segmental mobility of molecular chains, which isthe major influence of diffusion rate, can be tremendouslyincreased under the same thermal energy due to the lower Tgand larger amorphous regions compared with PET. Addition-ally, the lower temperature dyeing method can be performedwithout a carrier because MCDP fiber itself will probably havethe same role of enhanced segmental mobility as carriers do.Tensile Strength and Color Fastness. The values of the
tensile strength of three dyed SIP-modified copolyester fabricswith cationic dye were summarized in Table 1. The tensilestrength in the warp and weft direction of all the dyed samplesdecreased, and the loss of MCDP was lower than 3%. Thesimilar result of MCDP dyed with three disperse dyes can beobserved from Table S1. This indirectly proved that thedamage of both the cationic and disperse dyeing process to theMCDP fiber was so limited that it would not affect industrialuse.From Table 2 and Table S2, all cationic and disperse dyed
fabrics exhibited good fastness properties in washing and
rubbing fastness. For cationic dyeing, it is due to the strongelectrovalent bond linkage between the cationic dye and moreaccessible acidic group on MCDP. Meanwhile, MCDP fiberswere found to have excellent fastness with disperse dyes due tothe effective trap of dye molecules within the amorphous regionof the fiber.
■ CONCLUSIONSThe present work developed a carrier-free and low-temperaturedyeing procedure for MCDP copolyester incorporated withsodium-5-sulfo-bis(hydroxyethyl)-isophthalate (SIP) and 2-
methyl-1,3-propanediol (MPD). The cationic and dispersedyeability of MCDP fabrics at different dyeing conditions wereevaluated. The results at optimized conditions show anoutstanding cationic dye utilization (99.0%) and deep dispersecolor yield (19.6−35.5% higher than HTHP-dyed PET) ofdyed MCDP, which can be explained by the lower glasstransition temperature and crystalline degree observed fromDSC and XRD analysis. Meanwhile, high quality dyed MCDPfabrics were obtained with excellent tensile strength and colorfastness.An advantage of our method is that sufficient dyeing of
polyester fabrics can be accomplished with a reducedtemperature without using high pressure or carrier, whichindicates the use of less energy and safer processing conditionscompared with those of conventional processes. Anotheradvantage is that the ultradeep color of dyed MCDP sampleswas achieved using this method in contrast to HTHP-dyedPET dyeing before alkali pretreatment. This fact indicates thatthe process can be operated using less dyestuff to get the samedepth and requires less and safer chemicals than the usualprocesses. That is to say that the eco-friendly and low-costdyeing of MCDP in this work signicantly contributes to theincrease the sustainability of conventional PET dyeingprocesses.
■ ASSOCIATED CONTENT*S Supporting InformationThe Supporting Information is available free of charge on theACS Publications website at DOI: 10.1021/acssusche-meng.6b00338.
Measurements for dye uptake, color yield, color fastness,and breaking strength test; three-point fitting of SIP-modified copolyester dyeing rate curves; tensile strengthand color fastness of HTHP-dyed PET and boil-dyedSIP-modified copolyester fabrics with disperse dyes(PDF)
■ ACKNOWLEDGMENTSThis work was supported by Program for Specialized ResearchFund for the Doctoral Program of Higher Education in China(No.20130075130002) and the National Natural ScienceFoundation of China (Grant No. 51203018).
Table 1. Tensile Strength of Three SIP-Modified Copolyester Dyed Samples with BR46
tensile strength (N) elongation at break (%) loss of strength (%)
■ REFERENCES(1) Burkinshaw, S. M. Chemical Principles of Synthetic Fibre Dyeing;Springer: Dordrecht, The Netherlands, 1995.(2) Cegarra, J.; Puente, P. Considerations on the Kinetics of theDyeing Process of Polyester Fibers with Dispersed Dyes. Text. Res. J.1967, 37 (5), 343−350.(3) Pasquet, V.; Perwuelz, A.; Behary, N.; Isaad, J. Vanillin, apotential carrier for low temperature dyeing of polyester fabrics. J.Cleaner Prod. 2013, 43, 20−26.(4) Arcoria, A.; Cerniani, A.; De Giorgi, R.; Longo, M. L.; Toscano,R. M. Carrier dyeing of polyester fibre with some disperse azo dyes.Dyes Pigm. 1989, 11 (4), 269−276.(5) Ingamells, W.; Peters, R. H.; Thornton, S. R. The mechanism ofcarrier dyeing. J. Appl. Polym. Sci. 1973, 17 (12), 3733−3746.(6) Roberts, G. A. F.; Solanki, R. K. Carrier Dyeing of Polyester FibrePart II − The Influence of Carriers on the Diffusion of Disperse Dyes.J. Soc. Dyers Colour. 1979, 95 (12), 427−431.(7) Harifi, T.; Montazer, M. Free carrier dyeing of polyester fabricusing nano TiO2. Dyes Pigm. 2013, 97 (3), 440−445.(8) Fite, F. J. C. Dyeing Polyester at Low Temperatures: Kinetics ofDyeing with Disperse Dyes. Text. Res. J. 1995, 65 (6), 362−368.(9) Tavanaie, M. A.; Shoushtari, A. M.; Goharpey, F. Polypropylene/poly (butylene terephthalate) melt spun alloy fibers dyeable withcarrier-free exhaust dyeing as an environmentally friendlier process. J.Cleaner Prod. 2010, 18 (18), 1866−1871.(10) Liu, L.; Cheng, L.; Yu, J.; Xie, H. Evaluation of the availability ofeasy cationic dyeable copolyester fibers as electrostatic flocking piles. J.Appl. Polym. Sci. 2011, 120 (1), 195−201.(11) Zhao, M.; Li, F.; Yu, J.; Wang, X. Preparation andcharacterization of poly (ethylene terephthalate) copolyesters modifiedwith sodium 5 sulfo bis (hydroxyethyl) isophthalate and poly(ethylene glycol). J. Appl. Polym. Sci. 2014, 131 (3), 10.1002/app.39823(12) Kim, T. K.; Son, Y. A.; Lim, Y. J. Thermodynamic parameters ofdisperse dyeing on several polyester fibers having different molecularstructures. Dyes Pigm. 2005, 67 (3), 229−234.(13) Zhao, G. L.; Wu, R. R.; Curiskis, J.; Deboos, A. Dyeingproperties of blends of wool/modified polyester fibers - Effects oftemperature. Text. Res. J. 2004, 74 (1), 27−33.(14) Lee, M.; Lee, M.; Wakida, T.; Saito, M.; Yamashiro, T.; Nishi,K.; Inoue, G.; Ishido, S. Ozone-gas treatment of cationic dyeablepolyester and poly(butylene terephthalate) fibers. J. Appl. Polym. Sci.2007, 104 (4), 2423−2429.(15) Ingamells, W.; Lilou, S. H.; Peters, R. H. The accessibility ofsulphonic acid groups in basic dyeable polyester fibers. II. Theinfluence of plasticization on the ion exchange process. J. Appl. Polym.Sci. 1981, 26 (12), 4095−4101.(16) Pal, S. K.; Mehta, Y. C.; Gandhi, R. S. Effects of heat setting ontensile and dye sorption characteristics of anionic modified PET-Acomparison with normal PET. Text. Res. J. 1989, 59 (12), 734−738.(17) Rao, B. R.; Datye, K. V. lonomeric Polyester Fiber. Text. Chem.Color. 1996.(18) Chen, B.; Zhong, L.; Gu, L. Thermal Properties and ChemicalChanges in Blend Melt Spinning of Cellulose Acetate Butyrate and aNovel Cationic Dyeable Copolyester. J. Appl. Polym. Sci. 2010, 116(5), 2487−2495.(19) Fu, C.; Gu, L. Structures and properties of easily dyeablecopolyesters and their fibers respectively modified by three kinds ofdiols. J. Appl. Polym. Sci. 2013, 128 (6), 3964−3973.(20) Hou, A.; Li, M.; Gao, F.; Xie, K.; Yu, X. One-step dyeing ofpolyethylene terephthalate fabric, combining pretreatment and dyeingusing alkali-stable disperse dyes. Color. Technol. 2013, 129 (6), 438−442.(21) Li, G.; Yang, S.; Jiang, J.; Jin, J.; Wu, C. The complicatedinfluence of branching on crystallization behavior of poly(ethyleneterephthalate). J. Appl. Polym. Sci. 2008, 110 (3), 1649−1655.(22) Kint, D. P. R.; Munoz-Guerra, S. Modification of the thermalproperties and crystallization behaviour of poly(ethylene terephtha-late) by copolymerization. Polym. Int. 2003, 52 (3), 321−336.
(23) Li, X.; Wang, J.; Wang, H.; Cai, Z. Alkaline hydrolysis andpretreatment of trilobal high dimethyl 5-sulfoisophthalate sodiumcationic dyeable polyester. J. Text. Inst. 2015, 1−11.(24) Hsiao, K.-J.; Kuo, J.-L.; Tang, J.-W.; Chen, L.-T. Physics andkinetics of alkaline hydrolysis of cationic dyeable poly(ethyleneterephthalate) (CDPET) and polyethylene glycol (PEG)−modifiedCDPET polymers: Effects of dimethyl 5-sulfoisophthalate sodium salt/PEG content and the number-average molecular weight of the PEG. J.Appl. Polym. Sci. 2005, 98 (2), 550−556.(25) Aspland, J. R. Chapter 12: The Application of Basic Dye Cationsto Anionic Fibers: Dyeing Acrylic and Other Fibers with Basic Dyes.Text. Chem. Color. 1993, 25 (6), 21−26.(26) Wang, J.; Li, X.; Cai, Z.; Gu, L. Absorption kinetics andthermodynamics of cationic dyeing on easily dyeable copolyestermodified by 2-methyl-1,3-propanediol. Fibers Polym. 2015, 16 (11),2384−2390.(27) Teli, M. D.; Prasad, N. M.; Vyas, U. V. Electrokinetic propertiesof modified polyester fibers. J. Appl. Polym. Sci. 1993, 50 (3), 449−457.(28) Harwood, R. J.; McGregor, R.; Peters, R. H. Adsorption ofCationic Dyes by Acrylic Films II-Kinetics of Dyeing. J. Soc. DyersColour. 1972, 88 (8), 288−292.(29) Li, X.; Wang, H.; Cai, Z.; Yu, J. Cationic dyeing properties oftrilobal high dimethyl 5-sulfoisophthalate sodium salt (SIP) contentcationic dyeable polyester (THCDP) fabrics. J. Text. Inst. 2015, 106(8), 835−844.(30) Aspland, J. R. Chapter 9: The Structure and Properties ofDisperse Dyes And Related Topics. Text. Chem. Color. 1993, 25 (1),21−25.(31) Silkstone, K. The Influence of Polymer Morphology on theDyeing Properties of Synthetic Fibres. Rev. Prog. Color. Relat. Top.1982, 12 (1), 22−30.
ACS Sustainable Chemistry & Engineering Research Article
