Application And Research Of Bagasse Cellulose Based Film In Food Packaging

With the development of social economy and the improvement of living standards,human beings have higher and higher requirements for food packaging.Therefore,some biodegradable packaging with good mechanical properties,barrier properties and antibacterial properties have been vigorously promoted and developed.As a sustainable and biodegradable material,plant cellulose has been regarded as an effective substitute for petroleum resources.Bagasse cellulose comes from bagasse,the waste after sugar pressing of cash crop sugarcane.However,bagasse cellulose itself has the limitations of hygroscopicity,brittleness and poor functionality,which hinder its application and development in food packaging.In this paper,bagasse cellulose was modified to prepare cellulose-based composite films,whose properties were enhanced.At the same time,the chemical structure and properties of different composite films were studied,the strengthening mechanism was discussed,and the development prospect of bagasse cellulose-based films in food packaging was prospected.The main research contents of this paper are as follows:(1)In order to improve the mechanical properties of bagasse cellulose film,epichlorohydrin was added as crosslinking agent to enhance the mechanical properties of bagasse cellulose cross-linked films.The optimum synthesis conditions of cross-linked films were determined by single factor method.The introduction of crosslinking agent significantly enhanced the mechanical properties of bagasse cellulose,and changed the crystalline structure and crystallinity of cellulose in the film.(2)In order to improve the packaging applicability of bagasse cellulose cross-linked films,PVA was introduced as an enhancer of the barrier performance of composite films,and the bagasse cellulose /PVA composite films with excellent barrier performance was successfully prepared.At the same time,the composite films were hot pressed to improvedthe water resistance of composite films.FTIR and XRD results showed that PVA was successfully introduced into the composite film,and ether bond was formed in the composite film after hot pressing,and the crystallinity increased.At the same time,the thermal stability and mechanical properties of the composite films were inhanced.Furthermore,the test results showed that the mechanical properties of the composite films were still better under condition of high humidity after hot pressing.The water contact angle and barrier performance test showed that the water contact angle of the composite films increased after hot pressing,the water vapor and oxygen barrier performance were enhanced,the oxygen transmittance value was reduced by 6times compared with bagasse cellulose crosslinked film,and the sensitivity to water was decreased.(3)Aiming at the problem of insufficient functionalization of bagasse cellulose cross-linked film,Polyhexamethylguanidine hydrochloride(PHGH)was introduced into bagasse cellulose cross-linked film as an antibacterial agent,and bagasse cellulose /PHGH composite films with antibacterial properties were successfully prepared.Due to the introduction of PHGH,the mechanical properties of the composite film were further improved.The tensile strength of the composite film was 60.88 MPa,and the elongation at break is 23.15%,which was about 30.08% and 8.26 times higher than that of the original bagasse cellulose crosslinked films.The antibacterial results showed that when the initial concentration of PHGH was 3wt%,the antibacterial rate of the composite film against Escherichia coli,Staphylococcus aureus and Candida albicans were more than 95%.In addition,the results of degradation experiment showed that after 3weeks,the degradation rate of composite film(28.34%)was 7 percentage points lower than that of bagasse cellulose film(35.22%).