Synthesis And Characterization Of New Functional Polymer Self-healing Materials

Polymer materials will inevitably be damaged during processing and use.It is an important research direction to make polymer materials have self-healing properties.In addition,while giving material self-healing performance,make it have some other functions will help to further expand the application field of self-healing materials.In this thesis,a hydrophobic self-healing anti-corrosion coating was constructed by the extrinsic approach for the problem of easy damage of metal anti-corrosion coating.For preparing the coating,carboxylic acid-and fluorine-containing polymer microspheres were firstly synthesized,and the influence of the amount of methacrylic acid?MAA?,crosslinkers and the crosslinking degree were investigated on the final morphology of microspheres.The results of infrared spectroscopy proved that the existence of carboxyl and fluorine groups.Subsequently,the polymer of containing carboxyl groups was grafted on the surface of mesoporous SiO₂ nanorods.The corrosion inhibitors were carried in mesoporous SiO₂,and the carboxyl-induced pH-responsibility of the shell polymer could tune the release rate of corrosion inhibitor.The synthesized microspheres and pH-responsive core-shell nanocontainers were combined with epoxy resins to produce the hydrophobic self-healing anticorrosion coating.Compared with the pure epoxy coating,this smart coating not only has the hydrophobic property but also own the self-healing anticorrosion property in the scratch through the immersion test and the electrochemical test.After immersion in 3.5 wt%NaCl solution for 20 days,the extend width of corrosion scratch was only 51?m,basically no significant expansion.In addition,an intrinsic self-healing material with further functionalization potential was designed and synthesized in this paper,which is a diblock polymer.One block has an 2-ureido-4-pyrimidone?UPy?group that can form quadruple hydrogen bond,which can not only endow the material with self-healing properties,but also improve the mechanical properties of the polymer.The other block contains an active epoxy group that can undergo further ring-opening reactions to introduce other functions into the polymer.In the preparation of the polymer,a series of diblock polymer with different UPy contents were obtained by changing the molar ratio of active monomers with double bond containing UPy group?UPy MA?to butyl acrylate?BA?.The infrared absorption spectra showed the existence of UPy and epoxy groups.The results of mechanical and thermodynamic experiments demonstrated that increasing the content of UPy could improve the tensile strength and fracture toughness of the polymer and raise the glass transition temperature?Tg?.The sample with appropriate UPy group content was selected to verify the self-healing performance of the diblock polymer.The experimental results showed that the surface scratch could be completely repaired within 120 min at 90?.In addition,the active epoxy groups on the molecular chain can be used to introduce other functions into the polymer according to the actual needs.The two self-healing materials prepared in this thesis not only have self-healing properties,but also have hydrophobic properties and the potential of further functionalization,respectively,which can enhance the related properties of the materials or introduce other functions according to the actual needs,which can increase the application of self-healing materials in some fields.