Five kinds of process were applied to prepare pectin/chitosan（PEC/CS） composite membranes and the effect of membrane-forming conditions on the mechanical properties were explored, FT-IR, XRD and SEM were adopted to describe the structure of membrane. The results indicated that, the membrane prepared by dissolving the flocculent precipitate（formed by dissolving PEC/CS in the solution of acetic acid） with formic acid solution was smooth and transparent, and its tensile strength could reach 45.38 MPa, which was 1.42 times as that of gelatin membrane. The result of FT-IR analysis indicated that, a polyelectrolyte reaction happened between pectin and chitosan molecules through electrostatic and hydrogen bond interaction between -COOH and -NH2, and in this way, a composite material was formed. The result of XRD analysis showed that, the adding of pectin reduced the crystallinity of chitosan, a network structure was formed, and the mechanical property of the composite membrane was improved. The result of SEM analysis showed that, clear streaks could be observed in the surface of PEC/CS composite flocculent precipitate, and this indicated the poly-reaction occurred between pectin and chitosan molecules. Based on these experiment results.
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