Studies On Preparation And Properties Of Polythiourethane-based Marine Antifouling Coatings

Marine biofouling refers to the adsorption,growth and accumulation of marine microorganisms,animals and plants on the surfaces of marine objects(such as ships,concrete piers and oil pipelines)which were immersed in seawater.It not only seriously restricts the development and utilization of marine resources,but also leads to the serious accidents.The prevention of marine biofouling is a global problem to be solved urgently.At present,to paint the antifouling coatings is the most convenient,economical and effective approach for preventing marine biofouling.However,a mass of toxic antifoulants will be released to the environment and seriously damage the marine ecological environment during the antifouling coatings used.Therefore,it is a focus on developing eco-friendly marine antifouling coatings for marine antifouling research in the future.In this paper,we have prepared a series of HO-FPTU-x,PDMS-PTU-x,PDMS-PTU-08/CAP-x,PDMS-PTU/S-SiO₂-x and PDMS-PTU/ZnO-x materials based on polythiourethane at room temperature.The surface properties,adhesion strength onto the substrate and antifouling properties of these materials were investigated.The main results are as follows:(1)HO-FPTU-x polymers have been synthesized by hexamethylene diisocyanate,pentaerythritol tetrakis(3-mercaptopropionate)and 2,3,5,6-tetra-fluoro-1,4-benzenedimethanol.The surface properties and antifouling properties of HO-FPTU-x coatings were investigated by FT-IR,EDS and contact angle instrument.The results show the side chains simultaneously contain with hydrophobic and hydrophilic groups of HO-FPTU-x polymers and the fluorine element is evenly distributed on the coating surface.The surface of HO-FPTU-x coating can occur intense hydration.The hydrophobic and hydrophilic groups can commonly construct an“ambiguous''surface on HO-FPTU-x coatings after immersing into water.HO-FPTU-7.5 coatings have good anti-protein adsorption and anti-algal adhesion properties.HO-FPTU-7.5 coatings also have good antifouling performances in the marine field tests for 6 months.(2)PDMS-PTU-x polymers have been synthesized by a polymerization with hexamethylene diisocyanate,pentaerythritol tetrakis(3-mercaptopropionate)and?,?-hydroxypropyl terminated polydimethylsiloxane.The surface properties,adhesion strength and antifouling properties of PDMS-PTU-x coatings were researched by FT-IR,XPS,AFM and contact angle instrument.The results indicate that PDMS-PTU-x coatings have good hydrophobicity(>107.43°),low surface energy(22.02 m J·m^-2)and strong adhesion strength(>1.74 MPa)onto the substrate.PDMS-PTU-04 coatings have a weak removal strength(0.22 MPa)for pseudo-barnacles and good anti-protein adsorption and anti-algal adhesion properties.PDMS-PTU-04 coatings reveal good antifouling performances under static immersion tests for 10 months.(3)PDMS-PTU-08 polymer have been synthesized by adjusting the ratio of hexamethylene diisocyanate,pentaerythritol tetrakis(3-mercaptopropionate)and?,?-hydroxypropyl terminated polydimethylsiloxane.PDMS-PTU-08/CAP-x composite coatings have been prepared by PDMS-PTU-08 polymer mixed with a different amount of capsaicin,respectively.The surface properties and antifouling properties of PDMS-PTU-08/CAP-x composite coatings were investigated by FT-IR,AFM and contact angle instrument.The results demonstrate PDMS-PTU-08/CAP-x composite coatings have good hydrophobicity(>103.34°)and low surface energy(21.22 m J·m^-2)after capsaicin introduction.The capsaicin can be released(0.22?4.33?g·cm^-2·d^-1)continuously and stably from the coatings.The laboratory antifouling experiment results show PDMS-PTU-08/CAP-x composite coatings have good anti-protein adsorption and anti-algal adhesion properties.PDMS-PTU-08/CAP-5.0 composite coatings have good antifouling performances under static immersion tests for 9 months.(4)PDMS-PTU/Q-SiO₂-x and PDMS-PTU/S-SiO₂-x composite materials have been prepared by PDMS-PTU-04 polymer mixing with a different amount of hydrophilic SiO₂ and hydrophobic SiO₂ nanoparticles,respectively.The surface properties and antifouling properties of PDMS-PTU/Q-SiO₂-x and PDMS-PTU/S-SiO₂-x composite materials were investigated by FT-IR,FE-SEM,AFM and contact angle instrument.The results show that the micro-structures have been constructed on the coatings surface,PDMS-PTU/S-SiO₂-x composite coatings have good hydrophobicity(>107.03°)and low surface energy(19.25m J·m^-2)after nanoparticles introduction.The laboratory experiment results show PDMS-PTU/S-SiO₂-x composite coatings have good anti-protein adsorption and anti-algal adhesion properties.(5)PDMS-PTU/ZnO-x composite materials have been prepared by PDMS-PTU-04 polymer mixing with a different mass of ZnO nanoparticles,respectively.The surface properties and antifouling properties of PDMS-PTU/ZnO-x composite materials were researched by FT-IR,FE-SEM,AFM and contact angle instrument.The results show that the micro-structures have been constructed on the coatings surface,PDMS-PTU/ZnO-x composite coatings have good hydrophobicity(>108.75°),low surface energy(19.64 m J·m^-2),strong mechanical properties and adhesion strength(>2.23 MPa)after ZnO nanoparticles introduction.PDMS-PTU/ZnO-x composite coatings reveal good anti-protein adsorption and anti-algal adhesion properties under light conditions.