Study Of An Environment-friendly Polyurethane Marine Antifouling Coating Material

In recent years,Environment-friendly degradable low surface composite materials have attracted extensive attention.Waterborne polyurethane is widely used in marine antifouling fields due to its safe,non-toxic,excellent mechanical properties and easy design of molecular structure.This paper designs and synthesizes a new type of degradable waterborne polyurethane nanocomposites materials,low surface energy waterborne polyurethane nanocomposites and degradable low-surface polyurethane materials.The main application area is marine antifouling.The main contents of this paper are as follows:（1）Firstly,TiO₂-g-PLLA was prepared by ring-opening（ROP）polymerization,and then the degradable waterborne polyurethane nanocomposites was prepared by the block copolymerization.The nano-TiO2 was distributed uniformly in poly（lactic acid）.The addition of the nano titanium dioxide enhanced the heat resistance of degradable waterborne polyurethane nanocomposites and it can accelerate the degradation rate of polyurethane.By introducing nano titanium dioxide to improve the strength of the target product,at the same time,by adjusting the content of nano titanium dioxide and lactide,the crystallization and hydrophobicity of polylactic acid can be regulated and controlled.Finally,the degradation performance of the composite material can be controlled.The degradation of the coating and the loss of the fouling are achieved.Thus the effect of antifouling is achieved.Degradable waterborne polyurethane coating has better antifouling properties than ordinary polyurethane coatings.（2）The toluene diisocyanate（TDI）modified nano titanium dioxide was prepared,and then by using the combination of block copolymerization and clickation reaction,the synthesis of waterborne polyurethane nanocomposites with low water surface be designed.1H NMR and FTIR were used to characterize the nano titanium dioxide grafting TDI and the waterborne low surface energy polyurethane nanocomposites.As the content of hydroxylated fluoropolymer increased,the size of polyurethane emulsion was increased from 263 nm to323 nm and the contact angle increased from 62o to 106o.Its surface energy is 20N/m2 and has lower surface energy.The introduction of hydroxylated fluoropolymer has improved the thermal stability of waterborne polyurethane,and its resistance to water and organic solvent has also been improved.Because the composite material has lower surface energy,it can make the fouling not easy to adhere.Therefore,it has good application prospects in marine antifouling coatings.（3）The degradable low surface polyurethane material was prepared by using Michael addition reaction and block copolymerization.¹HNMR and FTIR data analysis showed that the biodegradable low surface polyurethane was successfully synthesized.The addition of fluorinated diols increased the thermal stability of polyurethane,and its water contact angle increased from 71.12^o to 108.24^o.The hydrolysis capacity of degradable low surface polyurethane is improved with the increase of PLLA..