The Preparation And The Properties Of The Composite Films From Cassava Starch And Guar Gum

In recent years, people realized starch as one kind of natural renewable polymer materials has so many advantages in producing biodegradable plastic. The raw starch films still haven't good application in industry because of poor mechanical properties and water resistance. This work is focused on the blending guar gum, anionic guar gum, and boric acid with cassave starch in the certain proportion to obtain composite films. The performance of different starch-based films is researched to explore potential application of starch-based films in the food and drug packaging area.Firstly, the raw guar gum,anionic guar gum with cassava starch were blended to make composite basic edible film in the certain proportion. The films with different contents of starch and guar gum were respectively prepared and characterized. Their properties were measured. The film containing cassave starch and guar gum with the ratio of 80:20 exhibited the good elongation (E). Compared with the pure starch film, tensile strength (TE) increased by 50%, E decreased by 30%, and the water vapor permeability decreased to 15.8%, water adsorption changed a little. The film containing cassave starch and anionic guar gum with the ratio of 80:20 had the good E. Compared with cassava starch film, the E increased by 142%, but the TE decreased by 22%. The water vapor permeability decreased by 5.4%, while the water adsorption decreased by 5.5%.Secondly, boric acid was added in pure cassve starch and guar gum respectively to make film with boric acid content 0%, 2%, 5%, 10% on the base of polysaccharides. Films were respectively prepared and characterized. Their properties were measured. The effect of boric acid contents on the properties of the films was studied.Finally, a group of the dialdehyde starch– guar gum composite films were obtained by blending guar gum with dialdehyde cassava starch. Films were respectively characterized. Their properties were measured. The film containing dialdehyde cassave starch and guar gum with content proportion 20:80 exhibited good E and TE. The water vapor permeability decreased with the increasing of guar gum contents.