How properties of cellulose acetate films are affected by conditions of iodine-catalyzed acetylation and type of pulp

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Rahim Yadollahi
  • Mohammadreza Dehghani Firouzabadi
  • Hossein Mahdavi
  • Ahmadreza Saraeyan
  • Hossein Resalati
  • Kirsi S. Mikkonen
  • Herbert Sixta

Research units

  • Gorgan University of Agricultural Sciences and Natural Resources
  • University of Tehran
  • Sari Agricultural Sciences and Natural Resources University
  • University of Helsinki

Abstract

The present study has been carried out to consider the effect of acetylation conditions and type of bleached pulps [Kraft and SO2–ethanol–water (SEW) pulps] on the properties of obtained cellulose acetates (CA) and their films. The acetylation reaction in the absence of solvent was performed by using acetic anhydride and iodine as a catalyst. The efficiency of acetylation and the degree of substitution, crystallinity, transparency, tensile strength, young modulus, differential scanning calorimetry, water vapor permeability (WVP), scanning electron microscope and atomic force microscopy images were studied. The results showed that the while the Young’s modulus and transparency increased by up to 8% of the catalyst due to the increase in iodine charge; higher iodine levels led to embrittlement of the film. The increase in the ratio of acetic anhydride to pulp (A:P) from 10:1 to 20:1 with 4% catalyst led to a reduction of the DS by 8–10%, the crystallinity by 25%, the Young’s modulus by 13–25%, and transparency by 1–34% of a CA obtained from SEW and Kraft pulp, respectively. With the use of higher amounts of the catalyst (8%) and a ratio of A:P equal to 20:1, all properties of CA were suitable for film preparation. WVP of films from Kraft pulp and SEW pulp showed a decrease of about 8.5% and 18% respectively when increasing the iodine amount from 4 to 8% in acetylation. The tensile strength of CA films was initially increased by enhancing the amount of iodine, but then reduced in a similar way to other properties. The condition of acetylation can be adjusted to produce a high-quality CA film according to the characteristics of the pulp used as raw material. Graphical abstract: [Figure not available: see fulltext.].

Details

Original languageEnglish
Pages (from-to)6119-6132
Number of pages14
JournalCellulose
Volume26
Issue number10
Early online date23 May 2019
Publication statusPublished - Jul 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • Acetylation, Iodine, Substitution degree, Transparency, Young modulus

ID: 34995969