Preparation,Characterization And Properties Of Esterified Plant Polysaccharides And Their Adhesives

Plant polysaccharides are widely sourced and cheaply available.They are a class of natural macromolecule compounds and are considered to be non-toxic and non-polluting renewable natural macromolecule biomaterials.It is a polysaccharide polymer consisting of a single type of glucose base unit;it is widely used in the fields of textile,papermaking,food,biomedicine and adhesives.This study used maleic anhydride,medomethylenetetrahydrophthalic anhydride and oxanhydride and plant polysaccharides to synthesize different monoesterified low-substituted plant esterified polysaccharides by wet synthesis,ultimately resulting in an environmentally friendly,cohesive property strong and water-resistant bio-adhesives.This dissertation mainly studied the preparation and characterization of three esterified plant polysaccharides and their performance as adhesives for pharmaceutical excipients.In this dissertation,three esterified plant polysaccharides were obtained by reacting maleic anhydride,mesityltetrahydrophthalic anhydride and oxanhydride with a polysaccharide emulsion under sodium hydroxide-controlled weak base conditions.The product was then characterized by infrared,degree of substitution,viscosity,and adhesion strength.The effect of the amount of anhydride on the degree of substitution,viscosity,and bond strength of the esterified polysaccharide was studied by a single factor experiment.The results showed that when the mass ratio of polysaccharide to maleic anhydride was 1:0.22,the degree of substitution and viscosity reached maximum.The optimum reaction conditions were determined as follows: the ratio of polysaccharide to maleic anhydride was 1:0.22,the reaction temperature was 35°C,and the reaction time was 2h.When the mass ratio of polysaccharide to Methylenetetrahydrophthalic anhydride was 1:0.22,the degree of substitution reaches the maximum;when the ratio was 1:0.18,the viscosity and adhesive strength reach maximum,and the bond strength meets the national standard;The optimum reaction conditions were determined as follows: the ratio of polysaccharide to maleic anhydride was 1:0.18,reaction temperature was 35°C,reaction time was 2h.When themass ratio of polysaccharide to ox anhydride was 1:0.22,the degree of substitution reaches the maximum;when the ratio was 1:0.18,the viscosity reaches the maximum,and when the ratio was 1:0.26,the adhesive strength reaches the maximum but the adhesiona The intensity does not meet the national standards;The optimal reaction conditions were determined as follows: the ratio of polysaccharide to maleic anhydride was 1:0.26,reaction temperature was 35°C,reaction time was 2h.By comparison we have determined the use of esterified polyoxyanhydrides as binders for wood and tablets,and for oxanic anhydride esterified polysaccharides when used as tablet binders to pass hardness,disintegration time limit,dissolution rate,mixing uniformity Performance testing and analysis were performed.Esterified plant polysaccharide adhesives are widely used in the fields of papermaking,wood,textiles,pharmaceuticals and adhesives,and plant polysaccharides are green natural renewable resources.Therefore,it is of great significance to the research of esterified plant polysaccharide adhesives.