Preparation And Application Of Functional Polymer Materials Containing Aldehyde

In recent years,the use of aldehyde groups as functional groups to construct new materials with specific reactivity has become a hot research topic in the field of polymer materials.At present,the preparation of most functional polymers remains at the stage of using petroleum resources as raw materials.However,petroleum rescources are facing problems such as resource shortages and serious environmental pollution.Researchers are working to find green and renewable resources to prepare new materials,which is expected to replace non-renewable petroleum resources to solve current environmental,social and economic problems.As lignin is a type of high-yield biomass,one of its downstream product,syringaldehyde,has an enormous potential for functional polymer preparation due to its aldehyde structure.Electrospinning and suspension polymerization techniques are common methods for preparing nanofiber materials and micron-sized microspheres,respectively.Both the fibrous materials and micro-spheres have the advantages of convenient operation,easy product availability,and large specific surface area.In this thesis,we synthesized an olefinic polymerizable monomer from the bio-based raw material syringaldehyde,and prepared nanofiber membranes and microspheres respectively by electrospinning and suspension polymerization approaches.The prepared materials showed good adsorption capability for amino acids.Microspheres have also proved to be useful for metal corrosion inhibition.The detailed research contents are as follows:1.Firstly,an aldehyde-containing acrylate monomer was synthesized starting from syringaldehyde,and then an aldehyde-containing polymer was obtained by solution polymerization of the monomer.The GPC test results showed that the molecular weight of the polymer was 20,000 g/mol.The polymer was fabricated into a nanofiber membrane material and the optimum spinning conditions were determined:the spinning solution mass fraction was about 20%,the DC voltage was about 18 kV,the propulsion speed was 1.3 mL/h,and the receiving distance was 15 cm.The results of scanning electron microscopy showed that the fiber diameter was about 300 nm and the diameter distribution was narrow.The prepared nanofiber membrane has good adsorption capacity for amino acids,and the relationship between adsorption capacity and adsorption time,fiber membrane usage,initial amino acid concentration and temperature was explored in detail.2.Two kinds of bio-based acrylate monomers were synthesized.Micron-sized copolymer microspheres were prepared by suspension polymerization.The results of scanning electron microscopy showed that the diameter of the microspheres was about 500 ?m,with a large number of pores in them.Through the Schiff base reaction,the further microspheres cotaning Schiff base moieties exhibited a good loading capacity for amino acids,and then the microspheres released the amino acid to regenerate the aldehyde structure in a neutral or acidic aqueous solution.This proves that the microspheres possess the ability to cyclically immobilize and release amino acids.The released amino acid can inhibit the corrosion of metals.