Study On Preparation And Properties Of Polysaccharide-Collagen Composites

Because of the need for sustainable development and low carbon economy,the utilization of biomass from nature resources has aroused increasing public attention.Such polysaccharide as cellulose,chitin,and such protein as collagen and gelatin have been widely applied in food,packaging,biomedicine,tissue engineering and other fields.In this thesis,polysaccharides and collagen-based materials were used to construct a variety of composites including regenerated cellulose-collagen porous tubes,regenerated cellulose-collagen sponges and microfibrillated chitin/gelatin films.Their structure and properties were characterized,and their application prospects in simulated blood vessels in vitro,medical dressings and food packaging were evaluated as well.The main works are listed as follows:Regenerated cellulose porous tubes and regenerated cellulose-collagen porous tubes were prepared by dissolving cellulose at low temperature in LiOH/urea aqueous solution with PEO as porogen.The effects of molecular weight,amount of PEO on the structure and properties of the tubes were investigated.The results showed that the porous regenerated cellulose tubes and the porous regenerated cellulose-collagen tubes prepared by using 120 kD molecular weight PEO at the weight ratio of cellulose to PEO of 9:1 exhibit good mechanical property.The tensile strength and burst pressure reach 1.27 MPa and 408.25 mmHg,respectively,and the compliance reaches 7.5%/100mmHg.In vitro cell experiment and MTT toxicity tests showed that the regenerated cellulose-collagen porous tube has good cytocompatibility.Collagen does good to the cell’s adhesion and growth.The tubes have a potential use in the construction of vitro vascular micro-environment.Cellulose was dissolved at low temperature in LiOH/urea aqueous solution.Regenerated cellulose sponge and regenerated cellulose-collagen sponge were prepared by introducing sodium dodecyl sulfate(SDS)as foaming agent and epichlorohydrin(ECH)as crosslinking agent.The effects of SDS amount,ECH amount and stirring speed on the structure and properties of sponges were investigated.The results showed that at the SDS content of 50 wt%,the ECH content of 4 mL/g and the stirring speed of 1400 rpm,the obtained sponge has stable and uniform pore structure,and good dimensional stability,water retention ability and mechanical properties.In vitro cell experiment and MTT toxicity tests showed that regenerated cellulose-collagen sponge has good cytocompatibility.Collagen could promote the adhesion and growth of cells.The sponges have potential applications in wound-dressing materials.Microfibrillated chitin/gelatin composite films were prepared by a solvent casting method.The nano-sized microfibrillated chitin was used as reinforce phase to improve the oxygen resistance,water-resistant and mechanical performance of the composite films.The morphologies were analyzed by scanning electron microscope(SEM),and the mechanical properties were investigated by texture analyzer.Oxygen permeability property,optical property and swelling property were investigated.The results indicated that the elastic modulus and tensile strength of microfibrillated chitin/gelatin composite film reach 2.2 GPa and 74.5 MPa,respectively at the microfibrillated chitin content of 8 wt%.The swelling ratio decreases to 11.63 at the microfibrillated chitin content of 6 wt%.In addition,chitin microfibrils effectively enhance the oxygen resistance of composite film without obvious loss of transmittance.The composite films could have potentials in food-packing.