Method for preparing chitosan complex film using glycerin and stearic acid as plasticizer

Abstract

The invention discloses a preparation method for chitosan composite membrane, which aims at providing a preparation method for the composite membrane with great toughness and less water and air permeability. The invention comprises the following steps that: the chitosan is dissolved by dilute acetum; the feed liquid ratio of the chitosan and the dilute acetum is 1:40 to 100 (weight / volume), and the chitosan is added with plasticiser, and then water-bath heating is implemented so as to make the chitosan dissolve completely, after that, the room temperature is lowered, so that the membrane solution is obtained; the plasticiser is a combination of the glycerin which accounts for 0.2 percent to 1.0 percent of the acetum in volume percent and the stearic acid which accounts for 0.3 percent to 0.8 percent of the acetum in mass percent. The prepared membrane solution is filtered for removing impurity, and is deaerated for half an hour, and then the membrane solution is poured into a clean glass plate, and is dried to form a membrane at the constant temperature of 40 to 80 DEG C; after the membrane is formed, and then stripping is implemented for generating the chitosan composite membrane. The invention adopts the glycerol and the stearic acid as the plasticiser, the composite membrane is prepared through the use selection, and the composite membrane not only has certain toughness and can keep a lower water and air permeability.

Description

technical field [0001] The invention belongs to the technical field of food packaging and preservation, and more specifically relates to a preparation method of a chitosan composite film using glycerin and stearic acid as plasticizers. Background technique [0002] Chitosan is prepared by deacetylation of chitin, which is widely found in the shells of crustaceans shrimp and crabs, the shells of insects, the cell walls of fungi (yeast, mold) and the cell walls of plants (mushrooms). The content on the earth is second only to cellulose. A large number of studies at home and abroad have shown that chitin and chitosan are non-toxic, and the U.S. Food and Drug Administration (FDA) has approved them as food additives. Therefore, chitosan is a non-toxic and safe natural polymer compound. Moreover, it is a functional polymer compound with special amino and hydroxyl functional groups on the molecular chain, so it is more suitable for use in the food industry than many synthetic poly...

AI Technical Summary

Problems solved by technology

[0005] Only use single plasticizer mostly in the preparation method of relevant chitosan composite film at present, i.e. glycerol or stearic acid, although glycerin can reduce the tensile strength of film, but has increased the gas permeability of film; Stearic acid can reduce the air permeability of the film, but the toughness decreases and the tensile strength increases

In the No. 9 Journal of Food Science in 2001, Ji Weizhi and others published the article "Research on the Film-forming Properties of Chitosan", which proposed to use a combination of glycerin and stearic acid as a plasticizer to make the film not only have a certain Toughness can also maintain low water and air permeability, but this article only provides guidance on the study of film-forming properties, and does not give the appropriate amount of glycerin and stearic acid