Effect of different polymers on the efficiency of water‐borne methyl amine adduct as corrosion inhibitor for surface coatings

Styrene/acrylic emulsion copolymer and water‐based short oil urethane alkyd resin were used as binders to prepare water‐based, environmentally friendly paints by using 0.5% emulsified methylamine adduct as corrosion inhibitor. The choice of the two above‐mentioned binders was based on the fact that styrene/acrylic emulsion copolymer is a nonconvertible binder, whereas short oil urethane alkyd resin is a convertible binder. The physical, chemical, mechanical, and corrosion properties of the paint films were evaluated and compared with a commercially known anticorrosive water‐based paint. It was found that the prepared paints have unique desirable properties such as the following: they do not contain anticorrosive pigments (which contain heavy metals in their main chemical structure); they are solvent‐free; and they can be produced to match any color. Corrosion tests on the films of the formulated paints revealed that the short oil urethane alkyd resin is superior to the styrene/acrylic copolymer. Moreover, the corrosion inhibition properties of the paint films prepared from both binders are comparable with the commercially available paints containing anticorrosive pigments. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 879–885, 2002     

自抛光船舶漆丙烯酸树脂研究

介绍了一种含有羟基丙烯酸树脂的研制方法,讨论了各种单体配比、引发剂、溶剂、聚合温度、时间等因素对性能的影响。研制出一种微溶于水又具亲水体积膨胀的丙烯酸树脂共聚物。配制成船舶防污漆,提高防污及船舶航速的目的。     

Grafting. IV. Graft tercopolymers as antifouling resin

A graft tercopolymer CLR-g-(MMA–TBTMA) based on chlorinated rubber as the backbone and binary copolymer of methyl methacrylate and tributyltin methacrylate as grafted chains has been synthesized. This graft copolymer has been used for the formulation of controlled-release antifouling paints, and leaching rate behavior of toxin from such paints has been studied. The data have been compared with those obtained using controlled-release antifouling paint based on linear chain copolymer of methyl methacrylate and tributyltin methacrylate. The paint based on grafted copolymer is characterized by having a lower leaching rate and reduced time for attainment of steady-state leaching. Raft exposure studies indicate longer antifouling life compared to that of linear chain copolymer-based paint both having the same dry paint film thickness.     

Erosion of a model rosin-based marine antifouling paint binder as studied with quartz crystal microbalance with dissipation monitoring (QCM-D) and ellipsometry

In this study two surface sensitive methods, i.e. quartz crystal microbalance with dissipation monitoring (QCM-D) and ellipsometry, were used for erosion measurements of a rosin-based marine antifouling paint binder. Thin films of the binder were applied on sensor surfaces by the means of spin-coating and the effect of water velocity over the paint film, water temperature or ionic strength on erosion was investigated. Both the acoustic QCM-D model and the optical ellipsometry model gave comparable erosion results. The initial 2–50 nm rapid erosion of the top layer was followed by steady-state erosion rate until end of experiment. For example, the steady-state erosion rate was 12 nm/24 h in artificial seawater at 23 °C and with a flow of 200 μl/min over the paint surface as measured with QCM-D. The erosion rate increased with increased velocity and increased temperature. Ionic strength had no effect on the erosion rate of this model binder. At low water velocities the surface layer was highly dissipative indicating a water filled surface top layer or the formation of deposits on the surface. New characterization techniques that are able to study the erosion mechanisms on the nanometre scale are sought for as the binders get more technically complex containing, for example, nanoparticles or enzymes. Surface sensitive methods could be used to rapidly screen the effect of different binder chemistries or paint additives on the erosion during the paint development process.     

新型有机硅自洁耐沾污机理的研究

以有机硅树脂低聚物为主要成分制备的耐沾污剂，不仅具有优异的自洁耐沾污性能，而且固化迅速。用FTIR、GPC等分析仪器对有机硅低聚物的结构与性能进行了表征测试，并通过SEM、接触角测量仪等对影响有机硅防污剂的耐沾污因素及机理进行了研究。     

High-build soluble matrix antifouling paints based on vinyl resin

The aim of this work was to formulate and evaluate high-build, soluble matrix antifouling paints showing reduced solvent retention in the film and sufficient bioactivity to protect structures submerged in sea water for long immersion periods.

The variables analyzed were binder composition, pigment content, toxicant type and thixotropic agent content.

Binder dissolution in sea water was achieved by employing WW rosin or calcium resinate; the control of the binder dissolution rate was achieved by using a vinyl resin as a cobinder. The paints were formulated with pigment volume concentrations of 40 and 45%; red cuprous oxide and triphenyl tin fluoride were used as the main toxicants. The rheological additive employed was hydrogenated castor oil at levels of 2.0 and 2.5 wt.% in the paint.

The bioactivity of the antifouling paints was determined in the natural environment (30 month immersion in sea water).     

Preparation and characterization of a novel conducting nanocomposite blended with epoxy coating for antifouling and antibacterial applications

In this study, novel epoxy-based paint was synthesized to be applied on carbon steel. The composition of the paint mainly contains epoxy mixed with an electronically conductive polymer, polyaniline (PANI), alone and combined with its nanocomposite derivation containing ZnO nanorods as an additive. The antifouling properties of the paint applied on carbon steel were investigated. The conductive nanocomposite was synthesized by an in situ chemical oxidative method of aniline in the presence of ZnO nanorods and then well characterized. The antifouling behavior was evaluated for 9 months in the Caspian Sea and Persian Gulf. Results revealed that epoxy/PANI–ZnO nanocomposite coating can prevent accumulation of marine macroorganisms on the coated panel. In addition, the epoxy coating comprising PANI–ZnO nanocomposite as well as the epoxy/ZnO coating exhibit significant antibacterial characteristics against (E. coli and S. epi). We interpret the antifouling and antibacterial behavior of the paint with (i) the presence of emeraldine salt structure in PANI which develops a surface pH in a range of 4–5 preventing the adhesion of microorganisms on the surface and (ii) the antibacterial and antifouling properties of zinc oxide nanorods that occurred by the production of hydrogen peroxide on the surface of the coating.     

94—01无毒防污涂料的研制

无毒防污涂料是防污涂料发展的必然趋势。本文介绍了以无毒硅酸盐为主要防污剂、丙烯酸树脂为基料的无毒防污涂料的配方。讨论了颜基比、硅酸盐组成、溶剂体系和防污助剂等因素对涂料防污性能的影响。     

水性热反射隔热防水涂料的研制

选用自交联弹性丙烯酸乳液为成膜物质，并用偶联剂、纳米耐沾污剂进行改性，制成基料；以白水泥、硅灰为无机胶凝材料，添加空心玻璃微珠、滑石粉、重钙混合成粉料；当基料：粉料为1：1时制备的涂料，其涂膜不但具有优异的防水性能，还兼具隔热降温功能和耐污自洁功能。     

Temperature- and pH-sensitive membrane formed from blends of poly(vinylidene fluoride)-graft-poly(N-isopropylacrylamide) and poly(acrylic acid) microgels

Temperature- and pH-responsive membranes prepared from blends of poly(vinylidene fluoride)-graft-poly(N-isopropylacrylamide)(PVDF-g-PNIPAM) copolymer and poly(acrylic acid) (PAA) microgels in N,N-dimethylformamide (DMF) solution by phase inversion method. PAA microgels help PNIPAM chains largely enrich onto membrane surface. Furthermore, adding PAA microgels increases the porous size, porosity and hydrophilic property of the blend membrane. The membranes show temperature-sensitivity between 30 and 35 °C, and pH-sensitivity between pH 3 and 5 on permeating aqueous solutions. Meanwhile, the blend membranes keep good antifouling property even if one of the hydrophilic components becoming hydrophobic in response to temperature or pH stimuli, which is superior to single-sensitive PVDF membrane.     

Poly(N-vinylpyrrolidone)-grafted poly(N-isopropylacrylamide) copolymers: Synthesis, characterization and rapid deswelling and reswelling behavior of hydrogels

Poly(N-isopropylacrylamide)-block-poly(N-vinylpyrrolidone) diblock copolymer (PNIPAAm-b-PVPy) was successfully synthesized via sequential reversible addition-fragmentation chain transfer/macromolecular design via the interchange of xanthate (RAFT/MADIX) process, in which the chain transfer agent of xanthate was in situ afforded via the reaction of isopropylxanthic disulfide (DIP) with 2,2-azobisisobutylnitrile (AIBN). The RAFT/MADIX technique was employed to prepare the poly(N-vinylpyrrolidone)-grafted poly(N-isopropylacrylamide) copolymers (PNIPAAm-g-PVPy) with N,N-methylenebisacrylamide as the crosslinking agent. The comb-like PNIPAAm-g-PVPy copolymer networks with PVPy as the pendent chains were characterized by means of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS). The hydrogel behavior of PNIPAAm-g-PVPy networks was investigated in terms of swelling, deswelling and reswelling tests. With the inclusion of PVPy chains, the swelling ratios of the hydrogels were significantly enhanced compared to the control PNIPAAm hydrogel. It is found that the PVPy-modified PNIPAAm hydrogels displayed faster response to the external temperature changes than the control PNIPAAm hydrogel. The improved thermoresponsive properties of hydrogels are ascribed to the formation of the comb-like architectures in the copolymer networks.     

Acrylonitrile-based copolymer membranes containing reactive groups: effects of surface-immobilized poly(ethylene glycol)s on anti-fouling properties and blood compatibility

The anti-fouling properties and blood compatibility of poly(acrylonitrile-co-maleic acid) (PANCMA) membranes were improved by the immobilization of poly(ethylene glycol)s (PEG) on membrane surface. It was found that the reactive carboxyl groups on PANCMA membrane surface could be conveniently conversed into anhydride groups and then esterified with PEG. Chemical and morphological changes as well as biocompatibility on membrane surface were analyzed by Fourier transform infrared spectroscopy, elemental analysis, scanning electron microscopy, water contact angle, protein adsorption, and platelet adhesion. Results revealed that, with the immobilization of PEG, the hydrophilicity and blood compatibility of the acrylonitrile-based copolymer membranes were improved obviously. The molecular weight of PEG had an obvious influence on the properties of the PEG-immobilized membranes. Permeation behaviors for the studied membranes were investigated by water and bovine serum albumin (BSA) filtration experiments. Compared with the original PANCMA membrane, the membrane immobilized with PEG 400 (M_w=400 g/mol) showed a three-fold increase in a BSA solution flux, a 40.4% reduction in total fouling, and a 57.9% decrease in BSA adsorption.     

Preparation and characterization of antifouling poly(vinylidene fluoride) blended membranes

Poly(vinylidene fluoride) (PVDF) membranes have been widely used in microfiltration and ultrafiltration because of their excellent chemical resistance and thermal properties. However, PVDF membranes have exhibited severe membrane fouling because of their hydrophobic properties. In this study, we investigated the antifouling properties of PVDF blended membranes. Antifouling PVDF blended membranes were prepared with a PVDF‐g‐poly(ethylene glycol) methyl ether methacrylate (POEM) graft copolymer. The PVDF‐g‐POEM graft copolymer was synthesized by the atom transfer radical polymerization (ATRP) method. The chemical structure and properties of the synthesized PVDF‐g‐POEM graft copolymer were determined by NMR, Fourier transform infrared spectroscopy, and gel permeation chromatography. To investigate the antifouling properties of the membranes, we prepared microfiltration membranes by using the phase‐inversion method, which uses various PVDF/PVDF‐g‐POEM concentrations in dope solutions. The pure water permeabilities were obtained at various pressures. The PVDF/PVDF‐g‐POEM blended membranes exhibited no irreversible fouling in the dead‐end filtration of foulants, including bovine serum albumin, sodium alginate, and Escherichia coli broth. However, the hydrophobic PVDF membrane exhibited severe fouling in comparison with the PVDF/PVDF‐g‐POEM blended membranes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Techniques for the measurement of natural product incorporation into an antifouling coating

The control of biofouling can be achieved by a variety of methods but for an open system, such as a ship's hull, a protective paint coating is the most adopted method. The incorporation of a natural product extract directly into a coating has received little previous attention. This study has investigated a combination of the antifouling compound (a natural product extract) and the delivery system (control depletion polymer) investigated together. It was necessary to investigate the natural product incorporation into a coating and finally assess the antifouling system including the primer layers in the natural marine environment. Natural products must first be practical as antifoulants to be developed further into a functional system by their incorporation into surfaces or coatings. To demonstrate this, the natural product under investigation was homogenised into a blank proprietary antifouling paint system binder, applied to primed and un-primed ship grade steel and immersed in marine environments. Electrochemical techniques were used to investigate the effects of natural product incorporation into a coating. In addition, optical and scanning electron microscopes were used to assess the physical characteristics of the coating system. The most rigorous test for an antifouling system is a field trial. Field trials were completed at a raft exposure facility, in estuarine dock conditions at the Empress dock, National Oceanography Centre, Southampton, UK.     

A new approach in the development and testing of antifouling paints without organotin derivatives

Environmental concerns have led to a progressive withdrawal of antifouling paints containing organotin derivatives. Resanbio?, a cooperative research program, plans to develop new antifouling paints that are more compatible with living species. In the first stage, we studied specific acrylic polymers with a variable hydrophilic/hydrophobic balance and, in some cases, pendant hydrolyzable functions. To evaluate the ability of these materials for hydrolysis, biocides release, and erosion, test panels with formulated films were prepared and immersed in sea water. An analytical protocol was established to characterize the polymeric material, to reveal chemical reactions that occur during erosion and antifouling action, and to understand the influence of the resin chemical structure on the paint’s antifouling efficiency. The degradation of these binders was revealed by the appearance of a product resulting from the hydrolysis. This product was identified and quantified by GC-MS. The release of cuprous oxide as model molecule, due to its water solubility and biocide activity, was quantified by inductively coupled plasma. The different processes used are explained and illustrated by an example of an efficient, erodable, antifouling paint following 22 months of immersion.     

Surface control of hydrophilicity and degradability with block copolymers composed of lactide and cyclic carbonate bearing methoxyethoxyl groups

Block copolymers of L-lactide (LA) and trimethylene carbonate (TMC) derivatives bearing methoxyethyl groups [poly(TMCM-MOE1OM)-block-PLLA] were employed as spin-coated films on substrates, and their hydrophilic and degradation behaviors were investigated. Changing the solvents for film preparation, film thickness, and copolymer composition ratios varied the contact angles in the range of 84.3° ± 2.8° at 269 nm thickness and 18.2° ± 2.5° at 15 nm thickness. These contact angles showed dynamic changes from hydrophobic to hydrophilic properties, probably due to the methoxyethoxyl groups connecting the flexible TMC moieties in the copolymer. Immersion into water or hexane affected the dynamic contact angles. X-ray photoelectron spectroscopy analyses revealed that a large amount of hydrophilic groups was segregated onto the surface, although both LA and TMC units existed. Such dynamic contact angle changes were delayed by the crystallization of polylactide. The hydrolyzed behaviors of these films were examined by quartz cell microbalance, showing a slow degradation process.     

Preparation and evaluation of thermo-reversible copolymer hydrogels containing chitosan and hyaluronic acid as injectable cell carriers

Poly(N-isopropylacrylamide) end-capped with a carboxyl group (PNIPAM-COOH) was grafted to chitosan for synthesizing thermo-reversible chitosan-g-poly(N-isopropylacrylamide) (CPN), which was further grafted with hyaluronic acid (HA) to form hyaluronic acid-g-CPN (HA-CPN). PNIPAM-COOH, CPN and HA-CPN formed injectable free-flowing aqueous solutions and exhibited reversible sol-to-gel phase transition (above 5% polymer concentration) at 30 °C. Chemical properties and temperature-dependent physical properties of the polymer hydrogels, such as rheological behavior, phase transition kinetics, and water content were characterized in detail. The mechanical stiffness of hydrogels increased with the presence of chitosan in the copolymer, but decreased after conjugation with HA. Chitosan and HA grafting also endowed higher water content and resistance to volume contraction during phase change of the copolymer solution. In vitro cell culture experiments with chondrocytes and meniscus cells in HA-CPN hydrogel showed beneficial effects on the cell phenotypic morphology, proliferation, and differentiation. Progressive tissue formation was demonstrated by monotonic increases in extracellular matrix contents and mechanical properties.     

几种天然产物在海洋防污涂料中的应用研究

将天然产物齐墩果酸、蛇床子素和鱼藤酮作为防污剂,分别制备海洋防污涂料,在厦门海域检验其海区防污效能,并与已报道在厦门海域具防污效能的天然产物喜树碱进行比较,发现蛇床子素和鱼藤酮在海区挂板2个月内显示出一定的防污效能,齐墩果酸没有呈现出防污效能,而喜树碱的海区防污效能明显优于上述3种天然产物。另外,将喜树碱与鱼藤酮进行1∶1复配,并将这2种天然产物与氧化亚铜、N-(2,4,6-三氯苯基)马来酰亚胺(TCPM)和吡啶硫铜锌(ZPT)这3种防污(助)剂分别进行1∶1复配,共获得7种复配防污剂,制备相应的海洋防污涂料以检测其防污效能,发现喜树碱-TCPM、喜树碱-ZPT以及喜树碱-鱼藤酮这3种复配防污剂具良好的防污效能。进一步在上述涂料中选取了防污效能最优的含喜树碱涂料,在福建东山海域和海南陵水海域分别进行了海区挂板试验,结果表明含喜树碱涂料在这2个海域均显示出稳定、优异的防污效能,且期效可达13个月以上。文中研究为推进天然防污产物在海洋防污涂料中的应用进程提供了重要资料。     

Synthesis and physicochemical characterization of a well-defined poly(butadiene 1,3)-block-poly(dimethylsiloxane) copolymer

For the first time, order-order and order-disorder transitions were detected and characterized in a model diblock copolymer of poly(butadiene-1,3) and poly(dimethylsiloxane) (PB-b-PDMS). This model PB-b-PDMS copolymer was synthesized by the sequential anionic polymerization (high vacuum techniques) of butadiene 1,3 (B) and hexamethylciclotrisiloxane (D₃), and subsequently characterized by nuclear magnetic resonance (¹H and ¹³C NMR), size exclusion chromatography (SEC), Fourier Transform infrared spectroscopy (FTIR), Small-Angle X-ray scattering (SAXS) and rheology. SAXS combined with rheological experiments shows that the order-order and order-disorder transitions are thermoreversible. This fact indicates that the copolymer has sufficient mobility at the timescale and at the temperatures of interest to reach their equilibrium morphologies.     

The influence of binder content on the water transport properties of waterborne acrylic paints

Diffusion coefficients and sorption isotherms of water in waterborne acrylic paint films and in the pure binder of the paints have been measured by gravimetric sorption. Solubility of water was found to enhance with the increased binder content in the paint films while the diffusivity of water decreased significantly. Sorption isotherms in the paint and pure copolymer films were correlated with the Flory Huggins theory and ENSIC model, respectively. Fickian diffusion was observed in both types of films and the kinetic data were best correlated with a numerical model which takes into account the concentration dependency of the diffusion coefficient and the dimensional change of the film due to sorption. It was concluded that the utilization of a simplified analytical solution may lead to significant errors in the estimation of diffusivities.