Elsevier

Carbohydrate Polymers

Volume 181, 1 February 2018, Pages 292-299
Carbohydrate Polymers

Research Paper
Effects of divalent anionic catalysts on cross-linking of cellulose with 1,2,3,4-butanetetracarboxylic acid

https://doi.org/10.1016/j.carbpol.2017.10.081Get rights and content

Highlights

  • Divalent PPA anions showed more efficient catalysis than monovalent ones.

  • 2Dcos was used to analyze the reactions between BTCA and cellulose.

  • Crosslinking and degradation of cellulose by BTCA are competing reactions.

  • The pH of BTCA bath played a key role in cotton finishing with PPA as the catalyst.

  • Fabrics treated at pH  3.2 presented good durability and satisfying strength.

Abstract

1,2,3,4-Butanetetracarboxylic acid (BTCA) can efficiently esterify cellulose with pyrophosphoric acid (PPA) as a catalyst to remove protons of reaction intermediates. However, valence and relative concentration ratio (RCR) of catalyst anions correlating to pH of finishing bath played a critical role in the reactions. Results here indicated that wrinkle recovery angle, tensile strength retention and ester absorbance of fabrics treated at pH of 2.8 showed higher values. It was a competing reaction for BTCA molecules to esterify or depolymerize cellulose. Importantly, divalent PPA anions were more efficient than monovalent ones in catalyzing the esterification between anhydrides and cellulose, which was confirmed by FTIR results and two-dimensional correlation spectroscopy analyses and by the RCRs of PPA anions and their changing rates versus pH. Furthermore, the higher catalytic efficiency of divalent anions was proved by the selected model catalysts. Meaningfully, the fabrics treated at pH  3.2 presented good durability.

Introduction

Cellulose can react with 1,2,3,4-butanetetracarboxylic acid (BTCA) to form ester cross-linkage, which has been applicable to formaldehyde-free anti-wrinkle finishing of cotton fabrics (Andrews, Morris, Donaldson, & Welch, 1993; Dehabadi, Buschmann, & Gutmann, 2012; Ji, Qi, Yan, & Sun, 2016; Welch, 1988, Yang, 2001). BTCA treatment of cotton fabrics is normally catalyzed by sodium hypophosphite (SHP) at low pH conditions, resulting in significant strength losses about 50% (Ji, Yan, & Sun, 2016; Kang, Yang, Wei, & Lickfield, 1998). Therefore, the investigation of alternative catalysts becomes an urgent task in this field (Harifi & Montazer, 2012; Ji, Tang, Yan, & Sun, 2015; Wang & Chen, 2005; Zhang, Ji, Yan, & Hu, 2017). In a previous study in searching for replacements of SHP, pyrophosphoric acid (PPA) was found to be a potential efficient catalyst at an optimal pH value, bringing similar wrinkle recovery angle (WRA) to catalyst SHP (Ji et al., 2015). Here, a more detailed investigation on the use of PPA in catalyzing BTCA ester cross-linking cellulose is conducted.

The pH value of finishing baths plays a vital role in catalyzing the reactions, and consequently shows an important impact on WRA and tensile strengths of BTCA-treated fabrics (Yang, Mao, & Lickfield, 2000). As reported (Ji, Zhao, Yan, & Sun, 2016; Kang et al., 1998; Yang, Wei, & Lickfield, 2000), two major reasons conferred the significant strength losses to the treated fabrics: intermolecular cross-linkage between cellulose chains by BTCA and depolymerization of cellulose macromolecules by the acids at a high curing temperature. The strength loss resulting from the cross-linkage (TSLC) is recoverable by totally hydrolyzing ester cross-linkages under alkaline condition. However, the strength loss due to the acid hydrolysis of cellulose (TSLA) is unrecoverable (Xu and Li, 2000a, Xu and Li, 2000b). Thus, it is meaningful to improve the strength of treated fabrics by maximally circumventing TSLA without lowering the WRA, which can be possibly achieved by controlling the pH value of finishing bath.

It was demonstrated that catalyst anions, associated with the pH of finishing baths, promoted the esterification between BTCA anhydrides and cellulose by removing the protons of reaction intermediates (Ji et al., 2015). Obviously, the alkalinity (or the valence) and the relative concentration ratio (RCR) of the catalyst anions will affect the completion of esterification reactions, since both of them can affect the removal process of protons. Although both phosphorous acid and phosphoric acid contain multivalent anions, they are unable to be ionized effectively at a pH range of 2.0–4.0. However, PPA is exceptional and can produce certain divalent anions due to its low pKa1 value (Ji et al., 2015, Zhao and Sun, 2015).

In this study, the effects of anionic valence of the catalyst PPA on ester cross-linking of BTCA with cellulose and on WRA values and strength losses of the BTCA-treated fabrics were investigated in detail, as a further complement for the anionic catalytic actions. Fourier transform infrared (FTIR) spectrometer, two-dimensional correlation spectroscopy (2Dcos) and RCR calculation were all employed to analyze their effects. In addition, three model catalysts were also selected for further confirmation.

Section snippets

Fabric and chemicals

Desized, scoured and bleached pure cotton fabrics (#400, density 98 g/m2, Test Fabrics, Inc., West Pittston, USA) were machine washed with detergent and tumble dried before use. 1,2,3,4-Butanetetracarboxylic acid (BTCA) was guaranteed reagent and purchased from Acros (New Jersey, USA). Sodium hypophosphite monohydrate (SHP) and pyrophosphoric acid (PPA) were analytical reagents and purchased from Sigma-Aldrich Co. (St Louis, USA). Sodium hydroxide was purchased from EMD Chemical Inc. (New

Properties of fabrics catalyzed by PPA

The pH of finishing bath is closely correlated with concentrations of PPA anions in finishing baths and would affect the cross-linking esterification reaction between cellulose and BTCA (Ji et al., 2015), consequently anti-wrinkle properties of the BTCA-treated fabrics. Thus, different pH conditions of the finishing baths were adjusted to treat fabrics, and wrinkle recovery angle (WRA) and tensile strength retention (TSR) results are presented in Fig. 1. Overall, WRA of fabrics treated at pH of

Conclusion

The divalent anions of catalyst PPA were more efficient than the monovalent ones in accelerating the esterification between BTCA anhydrides and cellulose, which was a possible reason of the increased TSLC with pH increasing. FTIR results and 2Dcos analyses also confirmed the hypothesis. Moreover, higher relative concentration ratio of PPA divalent anions and higher increasing rate were both beneficial to the improvement of anti-wrinkle properties of the treated fabrics. In addition, three

Acknowledgements

This work was supported by the Chinese National Science and Technology Support Program (No. 2012BAE11G00). Bolin Ji also showed his gratitude to the Outstanding Graduate Student Scholarship Fund of Donghua University and to the some financial support of Cotton Inc., USA. We also wanted to thank Dr. Shengtong Sun for his help in 2Dcos calculation.

References (29)

  • W.M. Haynes

    CRC handbook of chemistry and physics

    (2014)
  • B. Ji et al.

    Catalytic actions of alkaline salts in reactions between 1,2,3,4-butanetetracarboxylic acid and cellulose: I. Anhydride formation

    Cellulose

    (2016)
  • B. Ji et al.

    Investigation on functional properties of 1,2,3,4-butanetetracarboxylic acid crosslinked fabrics impacted by molecular structures and chemical affinity of catalysts

    Industrial & Engineering Chemistry Research

    (2016)
  • I.-S. Kang et al.

    Mechanical strength of durable press finished cotton fabrics part I: Effects of acid degradation and crosslinking of cellulose by polycarboxylic acids

    Textile Research Journal

    (1998)
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