| The ships navigating in the sea would be fouled by many types of marine life, which causes the friction force of hull surface to be increased obviously, the ships speed to be reduced and the fuel consumption and the maintenance cost of ship to be increased. In order to prevent the marine life attaching, it is the most effective that the surface of hull is coated by virulent antifouling coatings. Traditionally, fouling has been controlled by antifouling paint with tributyltin. They can accumulate in marine life and be difficult to degrade, which not only causes adverse effects in the environment, but also threatens the health of humans. The International Maritime Organization has issued ban to prohibit using antifouling coating included tributyltin after January 1, 2008. Consequently, research and development of environment benign antifouling coatings have already launched over the world.In this paper, series modified acrylic resin with different characteristics were synthesized referring to the adhesion mechanism of marine lives. Because of superior quality and lower cost, the acrylic resin was taken as foundation material. The infrared spectroscopy and the gelatin chromatograph have been used to detect the synthetic resin structures and the molecular weight. The results indicated that various kinds of acrylic monomer can be co-polymerized with zinc hydroxide and the polysiloxane compound through controlling the craft parameters and based on the free radical solution copolymerization principle, and then the copolymer can be obtained with a compatible hydrolysis characteristic. On the other hand, the acrylic resin modified with the organosilicon and possessed low surface energy can also be synthesized with acrylic monomer and organosilicon monomer. The advantages of the synthesis process are simple and safe, widespread raw material and a broad application prospect.The acid values of the modified acrylic resin were detected with the chemistry titrimetric method, and the contact angle between films and liquid and the surface energy of the films are examined with the JY-82 contact angle analyzer. The results showed that the performances including acid value, hydroxide value, hydrolisis rate and the storage stability are excellent, and both the zinc acrylate resin and the polysiloxane modified acrylic resin possess self-polishing characteristic. The contact angle between the film of the modified acrylic resin and water can reach to as high as 83°.Three types of antifouling coatings have been prepared by taking the series of modified acrylic resin mentioned above as the matrix material and mixing them with the different kind of antifouling boosters, aid agents, pigments and solvents. The coatings include'self-polishing zinc acrylate coating','self-polishing/lower-surface energy coating'and'bionic and non-toxic coating'. Based on the Chinese National Standard of GB6824-86, the Cu-ion release rates, the surface energies, the interaction between the water and the surface structures of the films have been examined with the GS-X150 surface tension analyzer, SEM and the GE5 digital microscope respectively, while the sea exposure test has also been carried out. The result showed that, all the three kinds of antifouling boosters (TCPM, Chlorothalonil and Diuron) can decrease the rates of Cu-ion release and thus increase the antifouling life and property of the coatings obviously. Besides improving the strength, additions of the micro scale pigments and the nano-scale SiO2 particles can also build up micro-nano mixed structures on the film surfaces as happened on the surface of the lotus leaf, and then a"air pad"could be found on the film surface. By existing of the air pad, the contact angles of the films can be significantly increased to as high as 150°, while the surface energies can be decreased to as low as 6mJ/m2, and the adhesion strength of the film on the matrix substances can reach to Grade I. in this case, the sea fouling lives can be retarded totally and solely by the physical mechanism. The sea exposure test confirmed that the antifouling property of the coatings has been increased considerably.Based on the adhesion mechanism of the sea life, the micro-nano structure of the low surface energy film and the'air pad'phenomena, as well as the physical-chemical interaction between the wettability of the surface and the contact angle, and detailed discussions on the antifouling mechanism of the low surface energy coatings have been reviewed systematically. Firstly, to increase the roughness of the solid surface can be helpful to result a super hydrophobic surface stably; secondly, to decrease the ratio of the interface between the solid and liquid can further increase the hydrophobic of the films of the low surface coatings. The results and discussions mentioned above have not been reported so far, and will be helpful to the research and application of the low surface energy and foul release coatings. |
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