| The large number and rapid growth of marine organisms attached to the surface of marine equipments can cause serious economic consequences,such as slowing down speed,increasing fuel consumption,intensifying corrosion.Utilizing antifouling coatings comes to be the most effective method to prevent or decrease the growth of fouling organisms.Among them,antifouling coatings containing organotin antifouling agent?TBT?or cuprous oxide?Cu2O?had been widely used due to their high antifouling efficiency and longevity.However,TBT and Cu2O have been forbidden for its high toxicity and environmental damage.Therefore,research and development of environmentally friendly antifouling coatings have become the current direction of marine antifouling coatings.Nonivamide is with bactericidal and bacteriostatic properties which has great prospects in marine antifouling for it is non-toxic and harmless to biodiversity and ecosystems.In this study,a novel antibacterial acrylate resin based on nonivamide was prepared by solution polymerization,and the characterization as well as antibacterial and antifouling properties were investigated.Firstly,the preparation technique of nonivamide modified acrylic resin was researched.The acrylic resin was successfully synthesized by a two-step reaction.Acryloyl chloride was grafted onto nonivamide by esterification to synthesize nonivamide-acrylate,this product was then polymerized with butyl acrylate?BA?,methy methacyrate?MMA?,acrylic acid?AA?,and styrene?St?by solution polymerization in a certain ratio to produce nonivamide-modified acrylic resin.Fourier transform infrared spectroscopy?FTIR?,NMR,elemental analysis?EA?,mass spectrum?MS?,gel permeation chromatography?GPC?,scanning electron microscope?SEM?,thermogravimetric analysis?TGA?and differential scanning calorimetry?DSC?were used to analyse the structure of nonivamide-acrylate and polymers.It was clear to see the peak of eater group in FTIR and NMR spectra indicating the successful composition of the ester.And the results of EA and MS further verified the conclusion.The better catalyst of this esterization was triethylamine?TEA?.The yield of the esterified products was about 85.3%.The results of polymers characterization revealed that nonivamide-acrylate was successfully grafted into polymers.The surfaces of polymer films were observed to be smooth and uniform.The TGA showed that the polymers had good thermal stability and could hardly be decomposed below 280°C.The Tg of the polymer was 31.2°C.The contact angles of the polymers films on tinplate increased from 77.5°to 86.2°with the increasing amount of nonivamide-acrylate.It can be concluded that the water repellence of the acrylate polymers can be improved by adding nonivamide-acrylate.The effects of temperature,reaction time,initiator concentration and the concentration of nonivamide-acrylate on the polymers were evaluated in detail,and the optimum reaction conditions were determined by the overall conversion rate of monomers.The polymers were composited by solution polymerization,and adhesion,hardness,TGA,antibacterial and antifouling properties of which were characterized.The results showed that the overall conversion rate of monomers and the viscosity of polymers came to increase at first and then declined with the increase of the reaction temperature,the number-average molecular weight?Mn?of polymers did not present a distinct variation tendency.The overall conversion rate of monomers and Mn of polymers both increased monotonously with the increase of reaction time,the viscosity of polymers displayed irregularly.With the increase of2,2`-azobis?isobutyronitrile??AIBN?concentration,the overall conversion rate of monomers had a pronounced increase,then remained stable and finally reduced slightly,the Mn increased a lot at first,and then gradually declined,the viscosity of polymers almost increased continuously.With the increase of the concentration of nonivamide-acrylate,the overall conversion rate of monomers increased at first and then decreased,the Mn and the viscosity of polymers increased continuously.In this study,the superior temperature of these experiments was 80°C,the reaction time was 10 h,the initiator concentration was 1.8 wt.%and the concentration of nonivamide-acrylate was 3.8 wt.%.The adhesion and hardness of the resin were great.The TGA revealed a stable thermal property of polymers.The antibacterial tests displayed a distinct antibacterial activities of polymer,especially the antibacterial rates of polymer membrane with 12.3 wt.%nonivamide-acrylate reached 100%.The antifouling tests showed that there was not algaes attached to the surface of polymer membranes,indicating good anti-adhesion effect of samples. |
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