Guan Y, Bian J, Peng F, Zhang XM, Sun RC. High strength of hemicelluloses based hydrogels by freeze/thaw technique.
Carbohydr Polym 2013;
101:272-80. [PMID:
24299774 DOI:
10.1016/j.carbpol.2013.08.085]
[Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 08/23/2013] [Accepted: 08/25/2013] [Indexed: 11/26/2022]
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.
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