Design,Synthesis And Properties Of Fluorine-containing & Catechol-containing Functional Polymers

Fluorine-containing polymer refers to the organic polymers which contain structure of C-F chains,which possess excellent chemical stability,thermo stability,weather resistance,low surface energy(hydrophobic and oleophobic),low friction,low dielectric and other characteristics,and act an irreplaceable role in various industries.Marine mussels adhered to a variety of surfaces firmly in saline and wet environments that attributed to the silk foot protein is rich in L-3,4-dihydroxyphenylalanine(L-DOPA).In recent years,L-DOPA and analog dopamine(DA)containing a catechol structure have been embedded in polymer structures to endue the polymers with biomimetic properties of polymers such as adhesion,coating,chelation,hydrogels have attracted widespread attention,and the biomimetic properties of polmers werederived the versatility and versatility of the catechol groups.Urushiol,the main and film-forming constitute of lacquer,is a mixture of substituted catechol derivatives with 15-17 carbon chains bearing 0-3 olefinic bond and the unique chemical structure endows various extremely performance of films.In this dissertation,we designed and synthesized several fluorine-containing monomers and catechol derivatives,as well as the synthesis of fluorine-containing and catechol-containing polymers were established.Furthermore,and the properties of polymers were also studied.The main contents are shown as follows:In chapter 1,we first briefly summarized the importance of functional polymers,then the properties,synthesis and research progress of fluorine-containing and catecholic biofunctional polymers were introduced.The applicationss in coatings and low dielectric constant materials of fluorine-containing functional materials,as well as surface modification of catecholic bionic functional polymers were also overviewed.In this context,we proposed the research idea and work contents in this thesis.Design,synthesis and properties of fluorine-containing polyurethanes with adhesive and anti-corrosion properties were discussed in chapter 2.Firstly,the fluorinated acrylate monomer was synthesized via sterification of perfluorohexylsulfonyl fluoride with p-hydroxybenzyl alcohol and acylation with acryloyl chloride.Next,Fluorine-containing polyacrylate polyol were obtained by copolymerization of fluorine-containing acrylate monomer,hydroxy acrylate monomer and other acrylate monomer,and polyacrylate polyol reacted with polyisocynanate to prepare pendant fluoro-chain fluorine-containing polyurethanes.The adhesive properties of polyurethanes were investigated included adhesion strength and anti-corrosion behavior.Furthermore,the probable adhesive and anti-corrosive mechanism was proposed integrated with surface wettability,elemental analysis,morphology characterizations.In chapter 3,preparation and properties of modified epoxy resin and PVDF epoxy resin blends were described.Firstly,a novel epoxy resin encapsulating material was prepared by selected epoxy resin,curing agent and reactive diluent.The mechanical properties,surface and interior morphology were characterized.Meanwhile,the influence of composition of components on mechanical properties and morphology was investigated,and the results showed that epoxy elastomer with high toughness,impact resistance,excellent low-temperature performance,wide damping temperature range.Moreover,the resin was blended with PVDF nanoparticles and fluorine-containing epoxy resin was obtained and their mechanical properties,morphology,dielectric properties,etc.were characterized.The results show that the epoxy/PVDF blend has excellent mechanical properties and low dielectric constant characteristics(low frequency 40-2 MHz,Dk at ca.1.0;high frequency 300 MHz～18 GHz,Dk at ca.2.0).Combined with analysis methods such as element and morphology,the self-assembled polymer chains driven by the differences in molecular chain compatibility were studied to give a nanoporous structure mechanism,so that the material has high mechanical strength and low dielectric properties.In chapter 4,series of catechol derivatives were synthesized via Mannich reaction of catechol,secondary amine and formaldehyde in aqueous phase,and purification of compounds by pH-controlled recrystallization was realized.The synthesized functional catechols not only exhibited dopamine-like oxidative cross-linking,but also possessed functional groups that are useful for synthesis of catechol-containing polymers.As a proof-of-concept application,two functional catechols,one bearing monohydroxyl and the other dihydroxyl groups at the 4-position,were incorporated into polyacrylate and polyurethane backbones,respectively,endowing these polymers with excellent coatability on various surfaces.Meanwhile,hydrogels could be prepared via polymers and mechanical properties were measured,the results showed the prepared hydrogels possessed rapid self-healing behavior,furthermore,the formation mechanism of hydrogels were illustrated.In chapter 5,the fluorine-containing biomimetic polyurethanes were synthesized via multi-step polymerization of fluorine-containing diol,4-substituted catechol and polyisocyanate.There are catecholic adhesive moieties,antifouling fluorine-containing and polyethylene groups in synthetic polyurethanes that could provide a new strategy for the design and synthesis of adhesive and anti-fouling coating materials.Besides,the adhesive and antifouling properties could be adjusted via the content of catechol and fluorine containing.In chapter 6,two type urushiol analogues which inspired by the characteristic structure of nature urushiol were synthesized via soybean oil as raw material conjugated with 3-substituted catechol which obtained from Mannich reaction of catechol.The urushiol analogues could be cured to a certain rigid coatings under UV irradiation.The coatings exhibited high thermostability and uniform morphology in surface and interior.Meanwhile,the anti-corrosion behavior of coatings on copper substrate were investigated and showed 99.9%inhibition efficiency in 3.5 wt%NaCl aqueous solutions.In addition,the mechanism of UV-induced polymerization of two types of urushiol analogues was investigated.