Study On The Influence Factors Of Sodium Chlorite's Retention Rate Of Slow Release Chlorine Dioxide Preservative Paper

Chlorine dioxide is a new anti-corrosion bactericidal preservative,which has a good bactericidal effect,it is high security and widely used in the field of fresh fruits and vegetables.Wood residues are kinds of resource-rich forest by-products,which would increase the efficient use of forest resources utilization,and get promoted economic growth.This study was about a new type of preservative paper which can release the chlorine dioxide slowly.The preservative paper was made up of two papers,A paper and B paper,which was loaded with sodium chlorite and tartaric acid respectively.At room temperature,the gas released period was up to two weeks.But sodium chlorite in A paper was reduced with the extension of time because of its instability.Given the high rention of sodium chlorite was very important to the release of chlorine dioxide,so A paper was considered as the research object,the stored temperature,coating liquid composition as well as the lignin content and structure was changed separately to study the main factors influencing the rention of sodium chlorite.Enzymatic hydrolysis method was used to extract lignin,and the structure was studied with the aid of infrared spectrum(IR),gel permeation chromatography(GPC)and nuclear magnetic resonance spectrum(1H-NMR),the results were as follows:(1)When sodium hydroxide was used as the stabilizer,and A paper was stored at a low temperature environment,the retention of sodium chlorate was mostly maintained.However,high temperature would accelerate the decomposition of sodium chlorite.(2)The lignin had significant effects to keep the retention of sodium chlorite:different paper bases were made by different portions of chemi-mechanical pulp and chemical pulp.Sodium chlorite retention would be lower if more lignin was contained in the paper base.Sodium dithionite hydrogen peroxide were used to bleach the pulp without removing lignin in the pulp.The results show that the pulp bleached by hydrogen peroxide could improve the retention.(3)Gel permeation chromatography(GPC)determination results showed that lignin after sodium dithionite and hydrogen peroxide bleaching treatment,the number average molecular weight was not reduced heavily but the weight average molecular weight was,the dispersion coefficient analysis showed that more degradation was caused by hydrogen peroxide bleaching system than average molecular.(4)Infrared spectrum(IR)and nuclear magnetic resonance spectrum(1 H-NMR)were used to analyze the structure qualitatively and quantitatively,the results showed that lignin degradation was caused by the bleaching process,while the functional groups of lignin were barely changed.Two bleaching methods would cause the decrease of carbonyl and guaiacyl lignin in the paper base,more were reduced by hydrogen peroxide treatment.showed that the aromatic ether bond was easy to participate in the reaction,they were unstable in the bleaching system.Two bleaching processes would destroy ?-O-4 bond,and reacedt with guaiacyl lignin,making it fall off from the lignin,so the content was reduced.Sodium dithionite would increase the number of methoxyl group while hydrogen peroxide would reduce it.The increase of carbonyl group was one of the main factors that caused the increase of sodium chlorite retention.