Antiwrinkle Finishing of Cotton Fabrics with 5-(Carbonyloxy succinic

Subscriber access provided by University of Otago Library

Article

Anti-wrinkle finishing of cotton fabrics with 5-(carbonyloxy succinic)benzene-1,2,4-tricarboxylic acid: Comparison with other acids Huan Qi, Cunyi Zhao, Feng-Ling Qing, Kelu Yan, and Gang Sun Ind. Eng. Chem. Res., Just Accepted Manuscript • DOI: 10.1021/acs.iecr.6b03287 • Publication Date (Web): 02 Nov 2016 Downloaded from http://pubs.acs.org on November 5, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Industrial & Engineering Chemistry Research is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Industrial & Engineering Chemistry Research

Anti-wrinkle finishing of cotton fabrics with 5-(carbonyloxy succinic)-benzene-1,2,4-tricarboxylic acid: Comparison with other acids Huan Qi a,b, Cunyi Zhao b, Feng-ling Qing a, Kelu Yan a,c∗∗, Gang Sun b∗ a

College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China b

c

Division of Textiles and Clothing, University of California, Davis, CA 95616, USA

National Engineering Research Center for Dyeing and Finishing of Textiles, Donghua University, Shanghai 201620, China

Abstract 5-(Carbonyloxy

succinic)-benzene-1,2,4-tricarboxylic

acid

(BSTA)

was

synthesized and applied as an effective crosslinking agent for cotton fabrics. In this study, BSTA was analyzed and compared with other two extensively investigated polycarboxylic acids, 1,2,3,4-butanetetracarboxylic acid (BTCA) and 3,3’4,4’benzophenone tetracarboxylic acid (BPTCA), in crosslinking cellulose. Possessing both aromatic and aliphatic carboxylic acid groups and respective properties, BSTA can crosslink cellulose as efficiently as BTCA without causing significant loss of tensile strength of the products. In addition, BSTA exhibits better hydrophilicity and higher affinity to cellulose than the aromatic acid. BSTA is able to produce anhydride under high temperature but it is not a rate determining step in the esterification process. The kinetic data of BTCA, BPTCA and BSTA with cellulose were calculated by measuring the concentrations of the carboxylic acids on the fabric, showing an order of BPTCA< BSTA< BTCA in reaction with cellulose. Keywords: Anti-wrinkle, polycarboxylic acids, molecular size, affinity, Arrhenius activation energy

∗

Corresponding author at: Tel.: +1 530 752 0840. E-mail address: [email protected](G. Sun)

∗∗

Corresponding author at: Tel.: +86 021 67792732. E-mail address: [email protected](K. Yan)

ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1. INTRODUCTION Polycarboxylic acids (PCAs) were proven capable of crosslinking cellulose efficiently under catalysis of sodium hypophosphite (NaH2PO2, SHP)1-4. However, not all of the polycarboxylic acids could provide desired anti-wrinkle properties on the crosslinked cotton fabrics, even though PCAs with three or more carboxyl groups bonded to the adjacent carbons of their molecular backbone were considered as proper crosslinking agents for cellulose5. Cellulose esterification by aliphatic polycarboxylic acids proceeds in two steps: formation of a cyclic anhydride intermediate by dehydration of adjacent two carboxyl groups, and a reaction between cellulose and the anhydride intermediate to form an ester6-7. Among all effective PCAs, 1, 2, 3, 4-butane tetracarboxylic acid (BTCA) has been shown as the most efficient one in crosslinking cellulose8-9. However, BTCA has demonstrated some limitations in wrinkle resistant treatment of cotton fabrics, including high production costs, use of large amount of sodium hypophosphite, and significant loss of the mechanical strength of the treated products10-12. Citric acid (CA) is also considered as an alternative. However, there is a severe yellowing effect on CA treated white fabrics, in addition to the drawbacks of BTCA, further preventing its application. Aromatic polycarboxylic acids were also used in crosslinking cellulose, and some treated cellulosic products include readily re-pulped paper with improved wet strength, pulp fluff with improved wet resilience, wood oriented strand board with improved moisture resistance, and textile products with improved durable press and reduced shrinking characteristics13. 3, 3’, 4, 4’-Benzophenone tetracarboxylic ACS Paragon Plus Environment

Page 2 of 22

Page 3 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


dianhydride (BPTCD) is an agent capable of incorporating both wrinkle-resistance and photoactive antimicrobial functions onto cotton fabrics14-16. BPTCD can be hydrolyzed into 3’,3,4’,4-benzophenone tetracarboxylic acid (BPTCA) in water, which could impart the fabric with improved wrinkle recovery performance while maintaining good mechanical strength. BPTCA can directly react with cellulose to form ester cross-linking structures through Fischer esterification reaction and demonstrate wrinkle resistance performance to cotton fabrics15-17, different from aliphatic polycarboxylic acids. The Fischer esterification reaction follows similar acid catalyzing mechanism but without formation of anhydride as an intermediate. The catalyst sodium hypophosphite works well on both reactions, together with sodium dichloroacetate and monosodium phosphate17. In a previous work, 5-(carbonyloxy succinic)-benzene-1,2,4-tricarboxylic acid (BSTA) was prepared by reacting pyromellitic dianhydride with hydroxyl succinic acid (DL-Malic acid) with intention to provide an acid with improved crosslinking ability and reduced damages to cellulose18. The incorporation of succinic group into the aromatic acid improved water solubility of the product without affecting its reactivity with cellulose. The product (BSTA) was applied on cotton fabrics as a novel crosslinking agent for anti-wrinkle finishing, and the resulting fabrics showed excellent performance similar to those treated by BTCA. To understand the excellent crosslinking effect of BSTA, a series of experiments were conducted in this study. BSTA was compared with two other extensively investigated acids in anti-wrinkle finishing performance. The wrinkle recovery angle (WRA) and strength retention ratio SR% of the treated fabrics under the same condition were analyzed as well. The ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 22

factors of acid structures, potential reactive sites, molecular size, and affinity to cellulose, ester formation rate and Arrhenius activation energy of overall esterification reaction were discussed to evaluate the differences of the PCAs on crosslinking cellulose. Both ChemBio3D Ultra 14.0 software and HSPiP 4.1.07 software were employed to discuss the structural features of the acids. Temperature dependent FTIR were used to analyze the crosslinking reactions of the acids on cellulose. Arrhenius activation energy of the overall esterification reaction was calculated based on the FTIR results under varied temperature conditions. The results provided a detailed understanding on BSTA crosslinking cellulose. 2. EXPERIMENTAL SECTION 2.1 Materials Cotton fabric used was Style 400 (weighting 98 g/m2) supplied by TestFabrics Inc. (West Pittston, PA), which was desized, scoured, and bleached without any other finishing processes. 5-(Carbonyloxy succinic)-benzene-1,2,4- tricarboxylic acid (BSTA)

was

synthesized

following

a

reported

procedure18.

1,2,3,4-butanetetracarboxylic acid (BTCA), 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BPTCD), dichloroacetic acid (DCA), potassium bromide and sodium hydroxide were purchased from Sigma-Aldrich Co. (St. Louis, MO, USA) or Fisher Scientific (Pittsburgh, PA, USA). All reagents were used as received without any further purification. 2.2 Fabric treatment Pre-weighed cotton fabric (30cm x 30cm) was impregnated in a finishing bath containing 0.2mol/L polycarboxylic acid and 0.1mol/L catalyst sodium salt of DCA. ACS Paragon Plus Environment

Page 5 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


The bath pH was adjusted to 2.0 with 10M NaOH. No other agents were added. Then the pre-weighed sample was soaked in the bath for 1 min at room temperature (~25oC) and then pressed through a two-roll laboratory padder (Burlington Textile Machinery Corporation, Burlington, NC, USA) to give a wet pick-up of ~100% based on the weight of fabric (o.w.f.). After that, the fabrics were dried at 100 oC for 2min. In comparison tests of three PCAs, all of fabric samples were cured at 180oC for 2min. The fabric thus treated was finally subjected to one home laundering washing/drying cycle to remove any chemical not bound to the cotton fabrics according to AATCC Standard Method 124 using a standard reference detergent. In calculation of Arrhenius activation energy of the reactions, the fabrics were cured in a laboratory oven under specific conditions as shown in Table S1. 2.3 Fabric properties Fabric samples were conditioned for 24 hours at a relative humidity 65 ± 2% RH and 21 ±1°C condition before measurements. Twelve specimens (six for warp and six for weft) were tested for wrinkle recovery angle according to American Association of Textile Chemists and Colorists (AATCC) method 66-1990 on a wrinkle recovery tester. Tensile strength was measured according to ASTM Testing Method D 5035-06 by using an INSTRON 5566 tester (Instron Corporation; MA, USA). Due to the fact that the warp direction strengths of fabrics are always higher than filling direction12, only tensile strengths in filling directions of the samples were measured. Strength retention (SR%) of fabric samples was calculated according to Equation 1, and an untreated sample was used as a control.

SR% = × 100%


Equation 1


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 22

Tt: tensile strength (N) of treated sample; Tu : tensile strength (N) of untreated sample. 2.4 Molecular size ChemBio3D Ultra 14.0 software (Perkin Elmer, USA) was used to calculate molecular volumes of chemicals19-20. The molecules were processed by following MM2 Minimize Energy function, and then by using Connolly Solvent Excluded Volume function. The Connolly Solvent Excluded Volume is the volume contained within the contacted molecule surface

21

.The radius (r) of an acid was calculated

based on

= π

Equation 2

where V is the Connolly Solvent Excluded Volume of an acid calculated by the program. 2.5 Hansen solubility parameters (HSP) Hansen solubility parameters (HSP) of acids were calculated by using HSPiP 4.1.07 software according to Y-MB method, and HSP values of water and cellobiose were obtained from the database in the software22. The distance Ra in Hansen space between an acid and water or cellobiose was calculated based on = 4∆ + ∆ + ∆

Equation 3

where δD is the energy from dispersion forces between molecules, δP is the energy from dipolar forces between molecules, and δH is the energy from hydrogen bonds. 2.6 Temperature-dependent FTIR analysis of fabrics Acid treated fabric samples after drying at 100 oC for 2 min without curing were prepared for temperature-dependent FTIR analysis. About 2.0 mg of grounded fabric sample was mixed with 200.0 mg of KBr to prepare a pellet for test. The pressed


Page 7 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


pellet was heated and the heating rate was 10◦C/min. The FTIR spectra using a pellet were recorded in every 10 oC from 130 to 200 oC, respectively, on a Nicolet 6700 FTIR spectrometer (Thermo Electron Co.,USA) in a range of 4000-400 cm−1 and a resolution of 4 cm−1. FTIR analysis was also employed in analyzing ester formation process under special temperatures. The pressed pellet was heated at 180℃ with different durations. FTIR spectra were recorded with every time intervals from 1 to 12 min on the spectrometer, respectively. 2.7 Titration analysis An acid-base titration method was applied to measure carboxylic contents on treated fabrics. A fabric sample (1.000g) was cut into small pieces and added into an Erlenmeyer flask, which contains 20 mL 0.050 mol/L NaOH solution and another 30mL distilled water. The mixture was stirred at room temperature for 20min and then titrated to pH 7.0 measured by a pH meter with 0.050 mol/L HCl solution. Consumed HCl volume was used for calculating the unreacted –COOH on the fabrics. Each cured sample was tested in triplicate. A dried sample was also titrated for initial carboxylic content [COOH]0 on fabrics. The specific details of Arrhenius activation energy calculation are discussed in section 3.5. 3. RESULTS AND DISCUSSION 3.1 Wrinkle performance of PCAs BSTA was compared with BTCA and BPTCA in crosslinking cotton fabrics. All of them were used following the same process and curing condition (180oC*2min). Wrinkle recovery performances of the treated samples before and after washing (b.w. ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

& a.w.) were investigated. As shown in Figure1, the results are significantly different after the treatments. Both BTCA and BSTA can impart high wrinkle recovery angle (WRA) values to the fabrics after curing. However, while BTCA and BSTA treated fabrics showed similar WRA values, tensile strength retention (SR%) of the BSTA treated one was significantly higher than that of the BTCA treated one. BPTCA treated fabrics demonstrated good SR% with over 70% retention, with slightly lower WRA value at 270o, consistent with the report that the aromatic acid treated fabrics possessed higher strength retention than that of those treated with aliphatic acids due to difference in diffusion distances of the acids in cellulose20.

Figure 1 Wrinkle recovery angles (WRA) and tensile strength retention (SR%) of BTCA, BPTCA and BSTA treated fabrics (b.w. =before washing; a.w.=after washing) Apparently, the structural features, including potential reactive sites, molecular flexibility, molecule size, as well as affinity to cellulose, of these acids, may affect


Page 8 of 22

Page 9 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


ester formation reactions and the winkle resistance of the treated fabrics, as well as the cellulose chains in cotton fibers-tensile strength. To investigate the impacts of these factors to these properties of the treated fabrics, different approaches were under taken. 3.2 Structural and molecular size differences Cellulose esterification by aliphatic polycarboxylic acids proceeds in two steps: formation of a cyclic anhydride intermediate by dehydration of two adjacent carboxyl groups, and a reaction between cellulose and the anhydride intermediate to form an ester. Only those aliphatic polycarboxylic acids that can form at least two cyclic anhydride intermediates will crosslink cotton cellulose well with the esterification reactions

5-7

. However, aromatic acids (BPTCA) can directly react with cellulose to

form ester structures and provide wrinkle resistance functions to cotton fabrics

17

.

BSTA has a unique structure, a combination of both aliphatic and aromatic polycarboxylic acids. The structural features of these three PCAs are presented in Figure 2 and Table S2.

Figure 2 Structures of PCAs Due to the fact that two adjacent carboxyl groups in aliphatic polycarboxylic acids can form anhydride, the selective sites for potential esterification are sites 1, 3 or 1, 4 in BTCA. BPTCA and BSTA contain aromatic acids, and all –COOH groups on



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 22

benzene ring can react with cellulose directly. The amount of potential reactive sites on aromatic acids equal to the amount of carboxylic groups on phenyl rings. Under the same amounts of carboxylic groups, aromatic acids should possess higher efficiency than aliphatic acid for forming potential crosslinking with cellulose. However, when one carboxylic acid reacts with cellulose on one phenyl ring in BPTCA, another carboxylic acid will become more sterically restricted. Thus, BPTCA highly likely only leads to a formation of crosslinking of cellulose with two ester bonds. Moreover, at least two carboxylic groups reacting with two cellulose chains can form the desired crosslinking. The distance between two –OH on carboxyl of PCAs represents the potential crosslinking length between cellulose molecules. The rotatable bond number (RBN) between two crosslinking sites on acids is a measure of molecular flexibility of the acid. RBN value is defined as the number of bonds which allow free rotation around themselves. The Connolly Solvent Excluded Volume (CSEV) is the volume contained within the contacted molecule surface

21

. CSEV

value can present the size of the molecule. BTCA and BPTCA have the same amount of –COOH groups, while BTCA showed higher crosslinking efficiency than BPTCA based on WRA results of the treated fabrics. Here, BPTCA has larger molecular size (CSEV value) than BTCA, making it difficult to diffuse or penetrate into cellulose but mostly stay on the surface of the fibers

20

. The surface reaction cannot produce the effective crosslinking in

cellulose and consequently resulting in low wrinkle performance5. BTCA has the suitable molecule size that can easily penetrate into cellulose for esterification. Although BPTCA has 4 potential reactive sites for crosslinking while BTCA has 2-3 ACS Paragon Plus Environment

Page 11 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


sites, BTCA shows higher crosslinking efficiency due to the even smaller molecular size and flexibility (RBN value). Aliphatic acids are more flexible than aromatic acids. BSTA is a combination of aromatic and aliphatic acids. The RBN value is 5-6 indicating that BSTA is a more flexible molecule compared to BPTCA. BSTA should have the aromatic acid groups reacting with cellulose first since the direct esterification reaction requires lower temperature 15, and the aliphatic acid groups will form anhydride but then the anhydride will react with cellulose in more flexible options. Thus, even though that BSTA has the similar molecular size as BPTCA it still demonstrated better crosslinking effect and higher WRA value than BPTCA. Therefore, smaller molecular size and higher molecular flexibility of PCAs contribute to better crosslinking efficiency. 3.3 Affinity of acids to cellulose Both BTCA and BSTA demonstrated good solubility in water at room temperature, while BPTCA needs to be dissolved under elevated temperature. Normally aliphatic acids have better water solubility than aromatic acids due to hydrophilicity difference. Additionally, the molecular affinities of an acid to cellulose and water may affect its interactions with cellulose and water, respectively. If an acid has high affinity to water, it will have high water solubility; if it has higher affinity to cellulose, it could be more approachable to cellulose chains, and possibly leading to higher reactivity to cellulose. Here, the Hansen solubility theory and parameters (HSP) distance (Ra value) between two molecules was used as a measure of affinity of two



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

molecules. The smaller Ra value indicates better affinity of the two molecules22. The Ra value was calculated according to the Equation 3. Table 1 Values of HSP and distances to water (Ra1) and to cellobiose (Ra2) (25 oC) of PCA

As shown in Table 1, HSP distances of Ra1 and Ra2 reflect PCAs’ affinities to water and cellobiose, respectively. The Ra1 values of all the PCAs are higher than Ra2, indicating that PCAs are more interactive with cellobiose than water. Comparing with the Ra1 values, BPTCA has the highest value of 26.9, least soluble in water among three acids, explaining its low solubility in water. Meanwhile, Ra2 values reveal the relative affinities of the acids to cellulose. The lower Ra2 means higher affinity and accessibility of acids to cellulose. Among them, both BTCA and BSTA have the lower values than BPTCA, meaning more interactive with cellulose, supporting the results of higher WRA values on BTCA and BSTA treated fabrics (Figure 1) or more effective crosslinking reactions. The results reveal that the acid affinity to cellulose affects the anti-wrinkle performance, which explains the BSTA molecule could crosslink cellulose more efficiently than BPTCA does even though the molecular size of BSTA is larger than BPTCA.


Page 12 of 22

Page 13 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


3.4 Temperature-dependent FTIR analysis of treated fabrics To monitor the PCAs crosslinking process on cellulose, temperature dependent FTIR technique was used5. The FTIR spectra of BTCA, BSTA and BPTCA under controlled temperatures are shown in Figure S1. Aliphatic carboxylic acids react with cellulose by forming corresponding anhydride first, and then the anhydride reacts with cellulose to result in ester bond 5. The formation of anhydride is critical for the esterification. From BTCA (Figure S1a) and BSTA (Figure S1b) FTIR spectra, two distinct bands appeared around 1850 cm−1 and 1780 cm−1 as temperature rose. These bands are due to the symmetric and asymmetric carbonyl stretching vibration modes of a 5-membered cyclic anhydride5,23, respectively. The intensities of two anhydride carbonyl bands increased with the curing temperature rising from 130 oC to 200 oC. An interesting phenomenon is that an anhydride peak also appears in BPTCA tablet (Figure S1c), representing formation of its anhydride under high temperature 15.

Figure 3 FTIR band intensity ratios of fabrics under increasing curing temperature



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Absorbance intensity around 2900 cm−1, representing the vibrational band of C-H on cellulose and unchanged during the treatments, was employed as a reference. The ratios of relative intensities (RI) of 1730/2900 and 1850/2900 represent the amounts of ester and anhydride formed on cellulose, respectively. The RI ratio value increased with the temperature increase. Linear relationships of temperature increase and RI values are shown in Figure 3. The linear correlation values (R2) of the peak ratios are in a range of 0.84 to 0.97, with lower ones mostly due to complication of two step esterification. Due to the direct esterification reaction mechanism, ester bond ratio of BPTCA crosslinked fabrics showed high correlation at 0.97. The symbol kx is used to represent the slope values of Figure 3 (rates of peak ratio change versus temperature). Table 2 Ester and anhydride forming rates of fabrics treated by three acids

The slope values (kx) of plots (Figure 3) are summarized in Table 2. The ester-forming rate (k1 0.841) of BTCA is slower than its anhydride forming rate (k2 0.867), indicating that the ester forming rate of BTCA is limited to its anhydride forming rate, consistent with the fact that anhydrides are intermediates of aliphatic carboxylic acids in esterification with cellulose. Comparing the kx value of BPTCA and BSTA, the ester-forming rate (k1 1.314) of BPTCA is much higher than its anhydride forming rate (k2 0.953), representing that esterification is not affected by the anhydride forming rate, and another supporting information of direct esterification between BPTCA and cellulose. BSTA also shows ACS Paragon Plus Environment

Page 14 of 22

Page 15 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


the similar results (k1 1.416, k2 1.033). Overall, esterification of aliphatic acids BTCA with cellulose is limited to the anhydride formation rate while aromatic acid BPTCA directly forms ester bond with cellulose. BSTA seems possessing reactivity of a combination of aliphatic and aromatic acids. 3.5 Arrhenius activation energy calculation To further investigate the temperature influence on crosslinking reactions of the acids, the Arrhenius activation energy values of the crosslinking reactions of PCAs were measured and calculated. The kinetics of the overall esterification reaction can be described as a pseudo-first-order reaction with respect to the PCAs concentration by Equation 4 24-25.

=−

!"# $

= %&'(# ')*#+ ',--#.

Equation 4

where r is the reaction rate, k is a rate constant, [PCA] is the concentration of polycarboxylic acid, [Cat] is the concentration of the catalyst, DCA, [Cell] the concentration of hydroxyl groups in cellulose and a, b, c are the orders of reaction. The catalyst [Cat] should be a constant in the reaction, while the [Cell] is incalculable and can be considered as a constant due to the abundant hydroxyl groups in cellulose. Thus, the overall esterification rate of the PCA with cellulose depends on the concentration of the PCA only, and assuming that it is a first order in term of [PCA] since the catalyst is not a strong acid. Therefore, the reaction rate can be expressed by Equation 5:

=−

!"# $

= % / &'(#

Equation 5

After integration, Equation 6 is obtained as:

lnPCA#5 − lnPCA#6 = −% / *


Equation 6


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 22

where [PCA]t and [PCA]0 are the concentration of PCA at time t and at the beginning (t=0) of the reaction, respectively. Thus the rate constant is equivalent to the value of the plot lnPCA#5 − lnPCA#6 against the curing time, t. This rate constant is considered as the overall esterification reaction of the PCAs though aliphatic PCA should have a two step mechanism. The relationship between the rate constant of the overall esterification and the temperature, T, is described by the Arrhenius plot (Equation 7):

%) = ( exp(−; /=)

Equation 7

where A is the frequency factor, ; is the Arrhenius activation energy of the overall esterification reaction, R the gas constant (8.314 J/(mol.K)) and T the temperature (K).

; is calculated from the slope of the plot ln ka against 1/T (Equation 8): ?

ln%) = ln( − A@

Equation 8

Therefore, it was possible to determine the rate constants at three different temperatures. The rate constants of the overall crosslinking reaction of BTCA, BPTCA and BSTA were measured at 140, 160, and 180 oC, respectively. To determine the rate constants, the data obtained from the measurements were modified according to Equation 6. The results of this modification are shown in Figure S2. The slopes and intercepts of the corresponding regressing graphs (Figure S3) were used to calculate the kinetic data shown in Table 3.


Page 17 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table 3 Kinetic data of reaction of PCA with cellulose under different curing temperatures PCA

ka

Ea

A

a

Error of Estimation

140oC

160 oC

180 oC

(kJ/Mol)

(s-1)

(mMol/g)

BTCA

0.0319

0.0681

0.1385

57.08

5.28E+05

0.006

BPTCA

0.0365

0.0597

0.0983

38.49

2.68E+03

0.006

BSTA

0.0586

0.1422

0.2042

48.82

9.45E+04

0.064

a

M

Error of estimate is calculated as Er = BF ((modelF − experimentalF ) /K)L/ ,

where n is the number of experimental values. The calculation results demonstrate that BTCA has the highest activation energy (57.08) followed by BSTA (48.82) and BPTCA (38.49). Aromatic acids have lower activation energy than aliphatic acids, revealing that aromatic acids can esterify with cellulose faster under the same curing condition. The BSTA was a combination of aromatic and aliphatic acid, showing the medium activation energy between BPTCA and BTCA. 3.6 FTIR analysis of fabric

Figure 4 FTIR analysis of BSTA cured fabrics at 180℃ ℃ for different durations The FTIR spectra of BSTA treated sample with varied curing times are shown in Figure 4. The peak intensities around 1730 cm−1 representing carbonyl stretching ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

vibration of esters rose as the curing time was increased. The ratios of relative intensities (RI) of 1730/2900 with varied times under 180℃ are summarized in Figure 5. From FTIR analysis results, the RI value increased rapidly after 1min curing of all three PCAs. The results showed that most of the esterification occurs in the 0~1min duration under 180℃. However, the RI values of BSTA and BPTCA tend to be unchanged after 3min curing time while BTCA still increases as the curing time prolongs. Aromatic acids BPTCA and BSTA are more reactive than aliphatic acid BTCA under the same curing condition, which is consistent with the Arrhenius activation energy calculation results.

Figure 5 FTIR analysis of cured fabrics at 180℃ ℃ Although aromatic acids present higher reactivity than aliphatic acids, the wrinkle-resistance performances of PCAs crosslinking cellulose are affected by the factors such as molecular size, flexibility, and affinity to cellulose, influencing crosslinking efficiency in cotton fiber. BSTA has the very unique structural feature of possessing both aromatic and aliphatic structures as well as very good affinity to


Page 18 of 22

Page 19 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


cellulose, making it a good crosslinking agent for cellulose. These results might be instructive to the future development of ideal crosslinkinga agents for cotton fabrics. 4. CONCLUSION BSTA treated fabrics showed better anti-wrinkle performance compared with BTCA and BPTCA. Molecular size and flexibility of crosslinking agents can affect overall efficiency, while BSTA has a medium molecular size and high molecular flexibility. In addition, BSTA exhibits good hydrophilicity and affinity to cellulose, making it the best among three tested PCAs. The FTIR analyses of reaction processes indicate that anhydride formation step of aliphatic acids is the rate determining reaction, while direct esterification of aromatic acids is the rate determining reaction even though its anhydride could still form under high temperature but is not affecting the crosslinking. The kinetic data (reaction rate constant, Arrhenius activation energy, frequency factor) of BTCA, BPTCA and BSTA with cellulose was calculated, and the activation energy increases in the order of BPTCA< BSTA< BTCA. Supporting Information The supporting information is available, including FTIR spectra (Figure S1) for experimental data of temperature dependent FTIR analyses of polycarboxylic acid treated cotton cellulose, the plots following Equation 6 (Figure S2) for determining reaction constants of BSTA under three temperatures, 140 oC, 160 oC, and 180 oC respectively, and the plots (Figure S3) following Equation 8 for determination of Arrhenius activation energy and frequency factors of three polycarboxylic acids with cotton. In addition, the heat treatment conditions of the PCA treated fabrics and the



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

structural features of polycarboxylic acids are listed in Table S1 and Table S2, respectively. ACKNOWLEDGEMENTS The first author is grateful for the financial support from China Scholarship Council for conducting research at University of California, Davis. REFERENCES Choi, H. M.; Welch, C. M.,; Morris, N. Nonphosphorus Catalysts for Formaldehyde-Free DP Finishing of Cotton with 1, 2, 3, 4-Butanetetracarboxylic Acid Part I: Aromatic N-Heterocyclic Compounds. Text. Res. J. 1993, 63, 650-657. (2) Choi, H. M.; Welch, C. M.; Morris, N. M. Nonphosphorus Catalysts for Formaldehyde-Free DP Finishing of Cotton with 1, 2, 3, 4-Butanetetracarboxylic Acid Part II: Sodium Salts of Fumaric, Maleic, and Itaconic Acids. Text. Res. J. 1994, 64, 501-507. (3) Welch, C. M.,; Andrews, B. K. Catalysts and processes for formaldehyde-free durable press finishing of cotton textiles with polycarboxylic acids, U.S. Patent 4,936,865, June 26, 1990. (4) Welch, C.M.; Andrews, B.K., Catalysts and processes for formaldehyde-free durable press finishing of cotton textiles with polycarboxylic acids. U.S. Patent 4,820,307, April 11,1989. (5) Yang C.Q.; Wang X. Formation of cyclic anhydride intermediates and esterification of cotton cellulose by multifunctional carboxylic acids: an infrared spectroscopy study. Text. Res. J. 1996, 66: 595-603. (6) Yang C.Q. FT-IR spectroscopy study of the ester crosslinking mechanism of cotton cellulose. Text. Res. J. 1991, 61: 433-440. (7) Yang C.Q. Infrared spectroscopy studies of the cyclic anhydride as the intermediate for the ester crosslinking of cotton cellulose by polycarboxylic acids. I. Identification of the cyclic anhydride intermediate. J. Polym. Sci., Part A: Polym. Chem. 1993, 31: 1187-1193. (8) Morris, C. E.; Morris, N. M.; Trask-Morrell, B. J. Variation in solubility and crystal form of meso-1, 2, 3, 4-butanetetracarboxylic acid. Ind. Eng. Chem. Res., 1992, 31, 1201-1203. (9) Yang C.Q.; Wang X. Infrared spectroscopy studies of the cyclic anhydride as the intermediate for the ester crosslinking of cotton cellulose by polycarboxylic acids. II. Comparison of different polycarboxylic acids. J. Polym. Sci., Part A: Polym. Chem. 1996, 34: 1573-1580. (10) Dehabadi; V. A.; Buschmann; H. J.; Gutmann, J. S. Durable press finishing of cotton fabrics: An overview. Text. Res. J. 2013, 83, 1974-1995. (11) Harifi, T.; Montazer, M. Past, present and future prospects of cotton crosslinking: New insight into nano particles. Carbohydr. Polym. 2012, 88, 1125-1140. (1)


Page 20 of 22

Page 21 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(12) Kang,

I-S.; Yang C Q . Mechanical strength of durable press finished cotton fabrics Part I: Effects of acid degradation and crosslinking of cellulose by polycarboxylic acids. Text. Res. J. 1998, 68, 865-870. (13) Anderson, R. L.; Cattron, W. W.; Smith Jr, V. F.; Fenoglio, D. J. Polyanhydride crosslinked fibrous cellulosic products and process for their preparation, U.S. Patent 6,248,879, June 19, 2001. (14) Hong, K. H.; Sun, G. Photoactive antibacterial cotton fabrics treated by 3, 3′, 4, 4′-benzophenonetetracarboxylic dianhydride. Carbohydr. Polym. 2011, 84, 1027-1032. (15) Hou, A.; Sun, G. Multifunctional finishing of cotton fabrics with 3,3′,4,4′-benzophenone tetracarboxylic dianhydride: reaction mechanism. Carbohydr. Polym. 2013, 95, 768–772. (16) Hou, A.; Sun, G. Multifunctional finishing of cotton with 3,3',4,4'-benzophenone tetracarboxylic acid: functional performance. Carbohydr. Polym. 2013, 96, 435-9. (17) Zhao, C.; Sun, G. Catalytic actions of sodium salts in direct esterification of 3, 3′ 4, 4′-benzophenone tetracarboxylic acid with cellulose. Ind. Eng. Chem. Res., 2015, 54, 10553-10559. (18) Qi, H.; Pan, J.; Qing, F. L.; Yan, K.; Sun, G. Anti-wrinkle and uv protective performance of cotton fabrics finished with 5-(carbonyloxy succinic)-benzene1,2,4-tricarboxylic acid. Carbohydr. Polym. 2016, 154, 313-319. (19) Álvarez, V. H.; Aznar, M. Thermodynamic modeling of vapor–liquid equilibrium of binary systems ionic liquid+supercritical (CO2 or CHF3) and ionic liquid+hydrocarbons using Peng–Robinson equation of state. J. Chin. Inst. Chem. Eng. 2008, 39, 353-360. (20) Ji, B.; Zhao, C.; Yan, K.; Sun, G. Effects of acid diffusibility and affinity to cellulose on strength loss of polycarboxylic acid crosslinked fabrics. Carbohydr. Polym. 2016, 144, 282-288. (21) Connolly, M. L. Solvent-accessible surfaces of proteins and nucleic acids. Science, 1983, 221(4612), 709-713. (22) Hansen, C. M. Hansen solubility parameters: a user's handbook. CRC press, 2007. (23) Qi, H.; Huang, Y.; Ji, B.; Sun, G.; Qing, F. L.; Hu, C.; Yan, K. Anti-crease finishing of cotton fabrics based on crosslinking of cellulose with acryloyl malic acid. Carbohydr. Polym. 2016, 135, 86-93. (24) Schramm, C.; Rinderer, B.; Bobleter, O. Nonformaldehyde DP Finishing with BTCA--Evaluation of the Degree of Esterification by Isocratic HPLC. Text. Chem. Color. 1997, 29 37-41. (25) Schramm, C.; Rinderer, B.; Bobleter, O. Kinetic data for the crosslinking reaction of polycarboxylic acids with cellulose. J. Soc. Dyers Colour. 1997, 113, 346-349.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

For Table of Contents only


Page 22 of 22

Antiwrinkle Finishing of Cotton Fabrics with 5-(Carbonyloxy succinic

Recommend Documents