Preparation And Study Of Galactomannan Modified Hydrogel

As a natural polymer material,polysaccharide gum has the characteristics of superior biocompatibility,natural degradability,and abundant sources.Therefore,the development of high-value utilization of polysaccharide gum resources can promote the development of new technologies such as biodegradable materials and pharmaceutical materials.Galactomannan is a kind of polysaccharide gum.It has good cross-linking and water solubility.It can form a stable high-viscosity aqueous solution at low concentration.It is widely used in food,medicine,petroleum drilling,and papermaking industries.This article uses galactomannan as raw material to design and synthesize galactomannan-poly?acrylamide-N,N'-bis?acryloyl?cystamine?hydrogel,carboxymethyl galactomannan-zinc chloride-polyacrylic acid hydrogel and graphene oxide-galactomannan-polyacrylamide hydrogel.Use analytical instruments such as Fourier Transform Infrared Spectrometer?FTIR?,Scanning Electron Microscope?SEM?,Ultraviolet Spectrophotometer Spectroscopy,Differential Scanning Calorimetry?DSC?,Thermogravity Analysis?TGA?,Universal Testing Machine and Multi-function Multimeter,The microstructure,degradation properties,mechanical properties,temperature responsiveness and swelling properties of galactomannan hydrogels were explored,and the applications of galactomannan hydrogels in drug carriers,sensors and dye adsorption were explored in depth.The main research work and results are as follows:?1?Using galactomannan?guar gum,GA?as raw material,a galactomannan-poly(acrylamide-N,N'-bis?acryloyl?cystamine with controlled degradation characteristics was prepared.The study found that by adjusting the content of GA can improve the mechanical properties of the hydrogel,when the content of GA is 10 wt%,the tensile strength and compressive strength of the hydrogel reached the maximum,respectively 40 k Pa and 250 k Pa.The continuous cyclic compression test shows that the hydrogel will not break under 60%,70%,and 80%strains,and quickly returns to its original shape,indicating that it has good fatigue resistance and resilience.The hydrogel is responsive to the reducing agent,and its degradation rate and drug release rate can be adjusted by the concentration of the reducing agent and the reduction time.As the concentration of the reducing agent?DTT?increases,the degradation rate of the hydrogel increases.When the DTT is 50 m M,the transmittance of the degradation solution is 22%.As the reduction time increases,the degradation rate of the hydrogel changes from fast to slow.Within 10hours,the quality of the hydrogel has dropped by more than 35%.It is expected to be used in drug carrier,tissue engineering and other fields.?2?First,GA was etherified to obtain carboxymethyl galactomannan?CMGG?,and then CMGG was used as a raw material to prepare carboxymethyl galactomannan-zinc chloride-polyacrylic acid hydrogel.The various cross-linking methods of the gel?including dynamic hydrogen bonding cross-linking,metal coordination cross-linking and covalent cross-linking?are mutually synergistic,which effectively improves the mechanical properties of the gel.When the CMGG content is 2 wt%,The compressive strength of the hydrogel is 452.71 k Pa.The rich coordination bond between Zn²⁺and-COOH gives the gel a flexible temperature response,which becomes soft when heatedand hardened when cooled.In addition,the hydrogel has good conductivity.When the Zn²⁺content is 90mol%,the ionic conductivity reaches a maximum of 4.44s/m,and the hydrogel has excellent performance in low strain and low angle cycling experiments.Repeatability and good inductance,so it is suitable for sensing small strain sensors.?3?First,the graphite flakes are oxidized to obtain graphene oxide?GO?,and then GO is used as a reinforcing filler to prepare graphene oxide-galactomannan-polyacrylamide nanocomposite hydrogel.The study found that the hydrogel has good mechanical properties.When the GO/GA content is 0.5 wt%,the tensile strength reaches a maximum of 96.98 k Pa and the elongation at break is 1986.69%.In addition,the hydrogel adsorbs the dye in two ways:covalent and non-covalent.When the GO/GA content is20wt%,the maximum adsorption and removal rate are 1.1mg/g and 84.2%,respectively.