Study On Preparation And Properties Of Chitosan Micro-Nanoparticles/PVA Blended Membrane

Food security and enviomental conservation are the hot issures in rescent years,the questions of food packaging materials for pro-enviroment,hazardous substance in packaging material migrated to the food and the packaging material degration difficuty emerged at the same time.In order to reduce the enviromental burden and reduce the packaging material cost,the paper focused on the degradable materials of PVA and chitosan,used the method of orthogonal experiment to explore the optimization coditions of degradable chitosan and chitosan nanoparticles and use the response surface methodology to optimize the conditions of PVA blend with chitosan nanoparticles.Then the paper explored the compatibility,air permibility,optical propertity,thermal stabilization,moisture absorption and antibacterial propertity,blend membrane,and the results as followed:(1)Chitosan degration results of orthogonal test showed that when the conditions was reaction temperature 60?,reaction time 6h,chitosan concentration 3%,H2O2 concentration 7%,the moculer weight was smallest.(2)Chitosan nanoparticles preparation orthoral test results showed that when the conditions was 2.5g/L of chitosan concentration,CS:TPP=5:1,stiring time 10min,ultrasound time 30min,the chitosan nanoparticles particle size was the smallest,and on this condition the particle size was 137nm.(3)The results of chitosan compared with chitosan micro-nanopaticles showed that the AFM result illustrated the paticle size of chitosan after its degration dimished,the paticle size of chitosan nanoparticles was about 100nm.FT-IR and XPS showed the hydrogen bond existed between CS,LWCS and NCS.The result of XRD testified that LWCS crystalline peak dropped compared with CS,the solubleness of LWCS and NCS enhanced.TG result showed the stability of CS was best,the second was NCS.(4)Response surface method obtained the results was that 21%PVA,PVA:NCS=14:1,1.25%glycerol,dry temperature 44?,on this condition the tensile strength was 36.8 MPa,elongation was 180.7%.(5)PVA compared with PVA/CS and PVA/NCS blend membrane,the analys results as follows,the hydrogen existed between PVA and CS and had good compatibility;the mechanical property was PVA/NCS>PVA>CS;optical property showed the the chitosan addition made the film turn yellow,NCS could absorb the UVB,so it can emprove the ability of ultraviolet absorb ability.CS and NCS could improve the air permeability of PVA,the permeability performance enhanced.The moisture absorption illustrated the GAB equation was fitted for the moisture absorption isotherm of PVA/CS,PVA/NCS and PVA film;the CS and NCS was added to the PVA,the antibacterial rate was up to 99.9%.