Chemical and physical crosslinking based dual-network cellulose gel system material

Abstract

The invention discloses a chemical and physical crosslinking based dual-network cellulose gel system material. The material comprises aquogel, aerogel and bioplastics, wherein a quantitative crosslinking agent is added to a cellulose solution and stirred to form partial chemical crosslinking cellulose gel, the gel is placed in a cellulose nonsolvent for physical crosslinking, and dual-network cellulose gel is obtained after washing. The dual-network cellulose aerogel is prepared by drying dual-network cellulose aquogel, and then is subjected to heat treatment at the temperature of higher than 150 DEG C, and carbon aerogel is obtained; dual-network cellulose aquogel or aerogel is subjected to hot pressing, and dual-network cellulose bioplastics are prepared. The prepared dual-network cellulose material has the advantages of good mechanical property, large specific surface area, high elongation at break and the like, can be easily processed into formed products with various forms such as a fiber form, a sheet form, a particle form, a thin film form, a cylinder form and the like.

Description

technical field [0001] The invention relates to a class of cellulose materials, in particular to a double-network cellulose gel-based material based on chemical and physical crosslinking, and belongs to the field of polymer materials. Background technique [0002] Polymer hydrogel is a three-dimensional polymer network formed by cross-linking hydrophilic polymers through covalent bonds, van der Waals forces, ionic bonds, hydrogen bonds, or chain entanglements (Adv. Mater., 2013. 25, 5011-5028; Chem. Soc. Rev., 2013. 42, 7335-7372; Chem. Soc. Rev., 2013), because of its high water content and water retention value, as well as the functional and The special geometric conformation of the gel network has been widely used in water treatment, tissue engineering, drug controlled release and other fields. The formation of polymer hydrogels is often accompanied by cross-linking or interchain interactions of various molecular chains. For example, Gong et al. obtained the basic gel s...

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Problems solved by technology

The invention patent of patent No. 200810197646.8 uses epichlorohydrin to prepare chemically crosslinked cellulose hydrogel, but because the molar ratio of added epichlorohydrin to cellulose is too high, all hydroxyl groups on the cellulose participate in the reaction to form chemical crosslinking point, so what is obtained is a completely chemically crosslinked cellulose hydrogel, which has poor mechanical properties and is brittle, and its compressive strength is only tens of KPa, which is greatly limited in practical applications (Macromol. Biosci., 2007, 7, 804-809; J. Mater. Chem., 2009, 19, 7771-7776)

Although the cellulose hydrogel obtained by physical cross-linking has high mechanical properties, because the cross-linking points form a three-dimensional network structure through hydrogen bonds and crystallization, the mobility of the cellulose molecular chains is limited, and the hydrogel’s Poor toughness, low elongation at break, and prone to fracture under bending or torsion conditions, so it is also limited in practical applications

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