High strength of hemicelluloses based hydrogels by freeze/thaw technique

Carbohydr Polym. 2014 Jan 30:101:272-80. doi: 10.1016/j.carbpol.2013.08.085. Epub 2013 Sep 12.

Abstract

Novel hydrogels were prepared from hemicelluloses, polyvinyl alcohol (PVA), and chitin nanowhiskers through 0, 1, 3, 5, 7, and 9 times of freeze/thaw cycle. These hydrogels were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), swelling property, and compressive strength. The repeated freeze/thaw cycles induced physically crosslinked chains packing among these polymers, and a phase separation caused by the hydrogen bonds. Larger pores led to a high swelling degree, whereas the formation of compact structure after multiple freeze/thaw cycles resulted in high mechanical strength and thermal stability. The highest compressive strength of these hydrogels was achieved by the 9 times of freeze/thaw cycles with compressive stress of 10.5 MPa. This work provides a remarkable way for the preparation of hydrogels with good mechanical properties by physical method.

Keywords: Chitin nanowhiskers; Freeze/thaw cycle; Hemicelluloses; Hydrogel; Polyvinyl alcohol.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chitin / chemistry
  • Compressive Strength*
  • Freezing*
  • Hydrogels*
  • Polysaccharides / chemistry*
  • Polyvinyl Alcohol / chemistry

Substances

  • Hydrogels
  • Polysaccharides
  • Chitin
  • hemicellulose
  • Polyvinyl Alcohol