Synthesis Of Fluorinated Polymers And Their Applications As Anti-biofouling Coatings

Fluorinated polymers have an extremely low surface energy, excellent optical and electrical properties, thermal stability and chemical resistance, so these polymers can be used in the fields of textile finishing, optical fiber claddings, microelectronics as well as antifouling agents. In the area of marine antifouling, scientists around the world have been making their efforts to research and develop novel environmentally benign marine antifouling paints or coatings since antifouling materials containing organotin derivatives have been banned by the International Marine Organization in 2003. Fluorinated polymers have been attracted by researchers due to their low surface tension and environmentally benign property. However, there are not effective fluorinated materials which can be used as marine coatings or paints on the market up to now, so it is very important for us to research and develop some novel promising functional fluorinated polymers capable as antifouling materials.In this dissertation, several classes of low surface energy fluorinated copolymers were designed, synthesized and characterized by FT-IR,1HNMR,19FNMR,GPC and XPS measurements. Then surfaces of slides and metals were coated with these polymers and their marine antifouling properties were evaluated by laboratory assays employing the fouling diatom Nitzschia and bacteria Staphylococcus aurous and Escherichia coli. After the primary biofouling investigation, some promising antifouling polymers were selected to be further used as the functional resins in the paints which were applied directly in the plate assay in the ocean of the coastal city---Qingdao, Shangdong province. Our work in the dissertation includes the following five parts.Partâ… . Two important monomers---fluorinated styrenes were synthesized through three steps from chloromethylstyrene and fluoroalkylalcohol. And then, the monomers reacted with methyl methacrylate, glycidyl methacrylate through a free radical polymerization reaction to form methyl methacrylate-co-glycidyl methacrylate-co-semifluoroalkyl substituted styrene terpolymers 4a and 4b, finally the prepolymers 4a and 4b were cross-linked under the ultraviolet irradiation from a mercury arc lamp in the presence of an organic photo acid generator WPAG 336. The antifouling properties of the cross-linkable terpolymers containing semifluoroalkyl substituted aromatic side chains were assayed using the fouling diatom Nitzschia and ubiquitous Staphylococcus aureous.Partâ…¡. The hydrophobic perfluoropolyether substituted styrene monomer and other styrene containing hydrophilic oligo(ethylene glycol) units were designed and synthesized. And then a novel amphiphilic copolymer was prepared by a free radical polymerization between the two monomers. The bacterial attachment experiments were carried out by using Escherichia coli and Staphylococcus aureous. Additionally, the further investigation of its antifouling property was studied employing the fouling diatom Nitzschia.Partâ…¢.The application of assembling technology on surfaces'modification was studied. A series of amphiphilic alkanethiols containing poly(ethylene glycol) and short fluoroalkyl chains were synthesized and grafted on the surface of the copper to form a thin film which was then evaluated as an antifouling coating. From the results of GA-FTIR and XPS measurements on the resultant self-assembled layers, it can be concluded that films were successfully formed on copper substrates. Finally, results of biofouling assays using bacterial Staphylococcus aureous and diatom Nitzschia indicated the good antifouling properties of these self-assembled films.Partâ…£. A class of biomimetic polymers was synthesized and studied. A series of biomimetic polymers containing natural antifouling phosphorylcholine groups (PC) and low surface energy perfluopolyether (PFPE) unit were synthesized by means of emulsion polymerization. By changing the proportion of hydrophilic PC groups grafted acrylate monomer and hydrophobic PFPE substituted styrene, we expect to find some promising biomimetic copolymers. The results of the number of adhesive cells of bacteria and diatom on the substrates indicated that polymers 8c,8d and 8e have the excellent antifouling properties. Partâ…¤. Research on coating formula of the paint. It has been known that the most important parts of antifouling paints are antifoulant and the film-forming resin, so based on the knowledge above, we first prepared 2-Methyl-4-isothiazoline-3-one (MI) and 5-chloro-2-methyl-4-isothiazoline-3-one (CMI) via a four-step synthetic protocol including addition, reduction, amidation and chlorination reactions. These organic compounds were designed as non-toxic antifoulants in place of the banned organotin compounds and toxic cuprous oxide. Then we try to select promising antifouling polymers 4a-b and 8c-e which were synthesized on the previous chapters as film-forming resins. Finally, antifouling paints were designed by using CM and CMI as antifoulants and polymers 4a-b,8c-e as film-forming resins. By plate assay in the ocean of Qingdao, it can be found that paints named AF-2 and AF-3 composed of resins 4b and 8c, respectively, have the best antifouling performances and be of effect for at least two months.