Study On Film Forming Process And Strengthening Mechanism Of Amylose

The rapid development of plastic industry has brought about increasing shortage of raw materials and environmental pollution.Starch comes from a variety of sources and is renewable,biodegradable and environmentally friendly.High amylose has strong intermolecular binding force and good film-forming performance,and has unique application value coMPared with common starch.It is an important green raw material for the preparation of starch based degradable plastics.However,due to the poor water resistance and mechanical properties of starch,cellulose,CMC and attapulgite were selected to enhance and modify the high amylose film.In this study,high amylose was used as the main raw material to investigate the conditions of gelatinization and film formation in water medium of starch.Meanwhile,appropriate plasticizers and enhancers were selected to plasticize and strengthen the starch film,FT-IR,TG,XRD,SEM and other test and analysis methods were used to analyze and characterize the structure of the film.In this study,the direct film forming mechanism of high amylose was firstly optimized.When the dosage of high amylose was 10 g and the gelatinizer was 1.5g,the compound plasticizer was 1.5g glycerin /0.75 g plasticizer1 /0.75 g plasticizer2.The gelatinization temperature was 95? and the gelatinization time was 3h.The prepared thermoplastic high amylose film had the best mechanical properties,tensile strength was 18.29 MPa,modulus of elasticity was 615.31 MPa,the elongation at break was18.21%.In the experiment of cellulose reinforced high amylose composite film,the cellulose reinforced high amylose composite film prepared by Solvent 1/ solvent 2/ solvent 3 solution after being dissolved at low temperature has better performance.When the dosage of high-amylose was 5g and that of cellulose was 3g,the cellulose reinforced high-amylose composite film prepared under the optimal conditions had good mechanical properties,the tensile strength was 25.40 MPa and the elastic modulus was 1,068.60 MPa.In the experiment of CMC reinforced high-amylose composite film,when the dosage of high-amylose was 5g and CMC was 5g,Under the optimal conditions,the tensile strength and elastic modulus of CMC reinforced high-amylose composite film were 27.33 MPa and 832.76 MPa.In the experiment of attapulgite reinforced high-amylose composite film,when the dosage of high-amylose was 5g and that of attapulgite was 1g,Under the optimal conditions,the tensile strength and elastic modulus of attapulgite reinforced high-amylose composite film were 19.13 MPa and 671.75 MPa.Finally,by coMParing the mechanical properties of amylopectin film and high-amylose film,it was found that the mechanical properties of high-amylopectin film were better and the flexibility of the film was better.