Self-polishing Copolymer Research Articles

Application of Self-Polishing Copolymer and Tin-Free Nanotechnology Paint for Ships

During a ship’s voyage, it is difficult to maintain its hull, and prolonged exposure to seawater can lead to the attachment of marine organisms, which can negatively impact the ship’s speed. The original self-polishing copolymer was a tributyltin-containing paint used for applying two layers of protective coating onto a ship’s bottom plate. According to International Maritime Organization (abbreviated as IMO) regulations, users are no longer allowed to use paints containing tributyltin. Therefore, manufacturers have developed a tributyltin-free paint, known as tin-free nanotechnology paint, which can be used as a replacement for the base coat on ship bottom plates. This study involves the use of a self-polishing copolymer spray and tin-free nanotechnology paint. A model coated with these two types of paint will be observed underwater to study the growth of marine organisms. Additionally, fuel consumption will be analyzed through underwater inspections and sea trials. Based on the experimental data, it is known that tin-free nanotechnology paint can significantly reduce the need for repairs in factories and greatly decrease maintenance costs when compared to self-polishing copolymers.

Controllable release of Cu ions contributes to the enhanced environmentally-friendly performance of antifouling Cu-bearing stainless steel coating prepared using high-velocity air fuel

Organic antifouling coatings represent an economical and efficient solution for addressing the marine biofouling. However, their application is constrained by issues of durability and toxicity. Therefore, this study has developed a metal-based antifouling coating by utilizing pre-alloyed copper-bearing stainless steel (Cu-bearing SS) powder in conjunction with high-velocity air fuel (HVAF) technology, aiming to achieve an environmentally-friendly and long-lasting antifouling coating. Compared to the self-polishing copolymer (SPC) coating, the adhesion strength of Cu-bearing SS coating increased to 69.0 MPa, which is approximately a 33-fold increase. The coating also exhibited enhanced wear resistance, the width and depth of the wear track for the Cu-bearing SS coating decreased 42.9 % and 81.0 %, respectively. Furthermore, the coating still demonstrated strong inhibitory effects on typical fouling microorganisms and algae adhesion due to Cu ions release process environmentally-friendly. The electrochemical techniques coupling with surface morphology observations were used to elucidate the antifouling mechanism. The variation trend of coating corrosion current was consistent with the release process of Cu ions, which was directly related to the evolution of the coating surface morphology. The three-stage change in the surface morphology of the 304 L-Cu SS coating contributes to the formation of a cyclic variation trend process of Cu ions. The evolution of surface morphology, accompanied by the controlled release process of Cu ions, had become a distinctive feature of antifouling properties for a metal-based coating.

A simple antifouling coating selection exhibits notable benefits for industrial fishing vessels

Impacts of biofouling were evaluated in-real conditions as a decision support system for industrial purse seiners and trawlers operating in the Mediterranean and the Black Sea (GFCM) in a fishing season. Initially, face-to-face interviews determined the most commonly used antifouling coatings among fishermen, resulting in the selection of five self-polishing copolymer (SPC) coatings. These SPC coatings, along with an uncoated reference panel, were immersed in the Black Sea's natural seawater environment for periodic fouling accumulation observations (SPC immersion tests). Additionally, selected SPC coating patches were applied on a fishing vessel to compare performances of the SPC coatings under the same conditions after a year of operation (namely ship tests). These ship test results were then compared with the outcomes from the static immersion tests. Finally, case studies were employed with the data generated from the static immersion tests for three fishing vessels operating in two different locations equipped with either trawl or purse seine. In addition to SPC coatings, foul release (FR) coatings were tested to compare their performance. Results indicated that applying an SPC coating to an industrial fishing vessel can yield fuel savings of 6%–10.26%, while a basic antifouling coating choice can save up to 3.11% in total fuel consumption over a fishing season in the GFCM area. Regardless of fishing gear used (purse seiner or trawler) or location of fishing activities conducted (Mediterranean or Black Sea), antifouling coating selection decision can reduce fuel consumption by up to 146.1M litres, fuel costs by £112.5M, and CO2 emissions by 0.42M tonnes for the regional GFCM fleet. These numbers are extrapolated to global fleet, estimating that fuel consumption can be decreased by up to 660.37M litres, fuel costs by £508.48M, and CO2 emissions by 1.9M tonnes based on the antifouling selection.

Corroboration of the Toms effect from a frictional drag reducing self-polishing copolymer

A novel frictional drag reducing self-polishing copolymer (FDR-SPC) was first developed by the authors. The FDR-SPC is a special derivative of an SPC that was designed to achieve skin frictional drag reduction in turbulent water flow by releasing polyethylene glycol (PEG) into water through a hydrolysis reaction. Thus, the FDR-SPC coating acts as a continuous medium accommodating countless, molecular-level polymer injectors. However, direct evidence of such PEG release has not yet been demonstrated. Here, we report the results of in situ PEG concentration measurement based on the planar laser-induced fluorescence (PLIF) method. Polyethylene glycol methacrylate (PEGMA) was probed by the fluorescent functional material dansyl, and the fluorescence intensity from dansyl-PEG was then measured to quantify the concentration in the flow. The near-wall concentration of dansyl-PEG is observed to range from 1 to 2 ppm depending on the flow speed, which corroborates the existence of a drag reducing function for the FDR-SPC. In the concurrent measurement of skin friction, the present FDR-SPC specimen exhibited a skin friction reduction ratio of 9.49% at the freestream flow speed U=5m/s. In the comparative experiment of dansyl-PEGMA solution injection, the skin friction was found to decrease by 11.9%, which is in reasonable accordance with that for the FDR-SPC.

Environment-friendly antifouling coating of Cu-bearing stainless steel prepared by pre-alloyed powder

Marine biofouling has become an urgent problem in the field of marine engineering equipment worldwide. In this study, an environment-friendly antifouling coating using pre-alloyed Cu bearing stainless steel powder as raw material was developed by cold spraying. The experimental results showed that pre-alloyed powder coating effectively inhibits the adhesion of marine fouling organism Pseudomonas aeruginosa. Due to the even distribution of Cu, it had better corrosion resistance and lower release rate of Cu ions compared with mixed powder coating, which made it appear protective of the marine environment. In addition, the coating has better wear resistance than commercial self-polishing copolymer coatings, which has the potential to become a new long-life marine antifouling coating.

Can vessel sea chest design improve fouling control coating performance?

Sea chests are arguably the most problematic vessel niche areas with respect to managing and preventing marine biofouling. This is partly due to the design and location of these structures, as well as the difficulty in managing them with conventional antifouling technologies. Antifouling coatings are typically designed for use on flat exposed hull surfaces that experience predictable flow conditions, and often perform poorly under variable flow conditions found in sea chest environments. This study examined whether custom-designed inserts retrofitted to experimental sea chests to alter their internal geometry and flow characteristics could improve antifouling coating performance. For in-laboratory sea chests coated with self-polishing copolymer (SPC) antifouling coatings, retrofitted inserts improved the polishing rate and erosion consistency of the coating; likely due to enhanced laminar flow and greater uniform wall shear stress over the surface of the sea chest, and the elimination of circulation zones and/or pockets of static water. For in-field sea chests coated with fouling-release coatings, inserts had little direct impact on biofouling accumulation compared to unmodified sea chests, with similar levels of fouling recorded per cm2 of sea chest surface. Inserts did however reduce the overall biomass of biofouling accumulated, through a reduction in available settlement area.

Degradable Vinyl Polymers for Combating Marine Biofouling.

Marine organisms such as barnacle larvae and spores of algae adhere to underwater surfaces leading to marine biofouling. This phenomenon has numerous adverse impacts on marine industries and maritime activities. Due to the diversity of fouling organisms and the complexity of the marine environment, it is a huge challenge to combat marine biofouling, which limits the development and utilization of marine resources. Since the International Marine Organization banned the use of tributyltin self-polishing copolymer (SPC) coatings in 2008, the development of an environmentally friendly and efficient anti-biofouling polymer has been the most important task in this field. Tin-free SPC is a well-established and widely used polymer binder for anti-biofouling coating today. Being a nondegradable vinyl polymer, SPC exhibits poor anti-biofouling performance in static conditions. Even more, such nondegradable polymers were considered to be a source of microplastics by the International Union for the Conservation of Nature in 2019. Recently, numerous degradable polymers, which can form dynamic surface through main chain scission, have been developed for preventing marine biofouling in static conditions. Nevertheless, the regulation of their degradation and mechanical properties is limited, and they are also difficult to functionalize. A new polymer combining the advantages of vinyl polymers and degradable polymers is needed. However, such a combination is a challenge since the former are synthesized via free radical polymerization whereas the latter are synthesized via ring-opening polymerization.In this Account, we review our recent progress toward degradable vinyl polymers for marine anti-biofouling in terms of polymerization methods and structures and properties of polymers. First, we introduce the strategies for preparing degradable vinyl polymers with an emphasis on hybrid copolymerization. Then, we present the synthesis and performance of degradable and hydrolyzable polyacrylates, degradable polyurethanes with hydrolyzable side groups, and surface-fragmenting hyperbranched polymers. Polymers with degradable main chains and hydrolyzable side groups combine the advantages of SPC and degradable polymers, so they are degradable and functional. They are becoming new-generation polymers with great potential for preparing high-efficiency, long-lasting, environmentally friendly and broad-spectrum coatings to inhibit marine biofouling. They can also find applications in wastewater treatment, biomedical materials, and other fields.

Constructing Dynamic Self-Renewing Multi-Level Microstructural Antifouling Surface by Combining Quaternarily Modified Go with Self-Polishing Copolymer

Constructing Dynamic Self-Renewing Multi-Level Microstructural Antifouling Surface by Combining Quaternarily Modified Go with Self-Polishing Copolymer

Permeability of a Zinc-Methacrylate-Based Self-Polishing Copolymer for Use in Antifouling Coating Materials by Molecular Dynamics Simulations.

Molecular dynamics simulations were used to investigate the solubility and permeability of H2O in a self-polishing copolymer (SPC) with two zinc methacrylate (ZMA) contents (Z2: 2 mol% ZMA; Z16: 16 mol% ZMA) and ethyl acrylate, methyl methacrylate, 2-methoxyethyl acrylate, and butyl acrylate as antifouling agents. Water was found to be more soluble in hydrated Z16 than Z2 because ZMA interacts strongly with H2O. In contrast, the diffusion coefficient of H2O in Z16 is lower than that of Z2 because H2O molecules are more constrained in the former due to strong ZMA/H2O interactions. Z16 was found to be significantly more permeable than Z2 over time. The SPC hydrated region in Z2 tends to expand toward the SPC region, while the analogous region in Z16 swelled toward both the SPC and H2O regions to leach SPC owing to the higher permeation of H2O into the SPC. These results reveal that H2O permeability can be controlled by adjusting the ZMA content, which provides insight into antifouling performance.

A novel marine antifouling coating based on a self-polishing zinc-polyurethane copolymer

A novel marine antifouling coating based on a self-polishing zinc-polyurethane copolymer

Evaluation of in-service speed performance improvement by means of FDR-AF (frictional drag reducing anti-fouling) marine coating based on ISO19030 standard

In previous reports by the authors, the drag reduction performance of a novel frictional drag reduction self-polishing copolymer (FDR-SPC) was presented. The drag-reducing functional compound polyethylene glycol methacrylate (PEGMA) was used in the synthesis process, thereby allowing the release of polyethylene glycol (PEG) into seawater by a hydrolysis reaction. In a laboratory skin friction measurement, a low-friction antifouling (AF) coating based on FDR-SPC was found to provide a 25% skin friction reduction compared with a conventional AF coating. This coating was then applied to the entire underwater surface of a 176 k DWT bulk carrier during dry docking in December 2015. The propulsion performance of the present vessel as well as the weather conditions were recorded over five years from November 2014 to December 2019. It was imperative that the hull coating performance be evaluated without being affected by the additional resistance component associated with weather conditions such as wind and waves. ISO 19,030 is proposed as a new international standard for that purpose. Based on this standard, in-service navigation data collected from the 176 k DWT bulk carrier, which amounts to 5.7 million data points, are analyzed to assess the speed improvement performance of the present frictional drag reduction antifouling (FDR-AF) coating. The analysis results indicate that the present coating leads to a speed increase of 3.72% over the conventional AF coating. The speed improvement effect is equivalent to power (fuel) saving of 11.7%.

Decomposition mechanisms of self-polishing copolymers for antifouling coating materials through first-principles approach

Density functional theory calculations were performed to explain the decomposition mechanisms of selected self-polishing copolymer (SPC) molecules like tributyltin (TBT), zinc methacrylate (ZMA), copper methacrylate (CMA), and triisopropylsilyl acrylate (TIPSA). The comparison between the different activation energies of the SPC molecules indicated that ZMA and CMA could be polished faster than TBT and TIPSA; moreover, ZMA and CMA exhibited stronger adsorption energy and lower activation energy than TBT and TIPSA. The results also indicate that the configuration and chemical species of the pendant atoms in the functional group of the SPC molecules are essential for their antifouling performance.

Evaluation of Anti-biofouling Progresses in Marine Application

Biofouling is detrimental and has been a major concern in the marine industry for several decades. This phenomenon is the accumulation, colonization and attack of organisms—which are both micro and macro, to assemblies, parts and/or structures that are submerged in freshwater and other marine environments. Even despite all the exceptional indispensable and indisputable characteristics of alloys such as steel, biofouling continues to be a major source of failures of these alloys, thereby limiting their use in service. This study presents a review of the existing means of protection against biofouling which are basically the use of paints and electrolytic deposition of anti-biofouling agents such as some nano-composite coatings. The different types of systems from the first-generational coatings such as tributyltin self-polishing copolymer paints to the novel nano-composite coatings were discussed. Ultimately, the use of nano-materials and composites consisting some anti-biofouling natural products has identified to be a promising way of combating biofouling issues in the maritime.

Effects of accelerated ageing conditions on the mechanism of chemically-active antifouling coatings

The accelerated ageing of chemically-active antifouling coatings was investigated by performing in vitro and in situ static/dynamic cycles. One of the main objectives of this study was to develop an ageing test able to predict long-term antifouling coating performances in less than one year with a mechanism which is representative to the natural ageing. One self-polishing copolymer (SPC)-based coating and one controlled depletion polymer (CDP)-based coating were selected because of their well-known distinct mechanisms of action. Five static artificial conditions were used in cycles and their influence on the ageing of two coatings was investigated. Comparison of two key parameters such as erosion of the coatings and formation of a leached layer or a depleted layer at the surface of the two coatings were investigated in accelerated and in situ tests. Results support the different mode of action of the two coatings. The static artificial conditions were shown to affect the residual antifouling efficiency differently. Deionized water buffered at pH = 8 with tris(hydroxymethyl)methylamine was the only static artificial condition that led to an acceleration of both the formation of a leached layer or a depleted layer at the surface of the two coatings and their erosion.

Protection Coatings for the Underwater Part of Ship’s Hull

In this article authors present a general consideration of the underwater part of ship’s hull protection by protective coatings, paying particular attention to antifouling paints. Following the presentation of the importance of ship’s hull maintenance and protection in order to make navigation safer and to keep the ship in operation for as long as possible, a summary is made of the main types of antifouling products used throughout the history up to the present time. As far back as a thousand years BC, people had developed techniques to protect objects from falling into disrepair and understood the importance of preserving construction materials in order to prolong their useful life and value. Marine industry has been developing day by day and attention is increasingly focused on the safety of ships and crews, as well as on the protection of marine environment. Tin-free self-polishing copolymer (SPC) and foul release technologies are currently applied, in addition to many alternative solutions being suggested. Modern approaches to effective environment-friendly antifouling systems and their performance are highlighted.

A brief survey of the procedure of hull corrosion and biofouling prevention technique in Eritrea and its effecton environment due to biofouling and improper way of biofouling prevention technique applied here

Corrosion is the gradual deterioration of material or its properties through a chemical reaction with the environment. Biofouling takes place in underwater ship hull. Micro-organism, vegetable and animal matter naturally attach to a ship’s hull If marine biofouling is not dealt with correctly, the accumulated fouling poses a risk of transferring invasive, non-indigenous marine species (NIS or NIMS) around the world with consequent damaging effects to local marine life and a reduction of biodiversity. One of the key means of NIMS is the badly fouled hulls of ships. In this research paper we are concerned with the hull corrosion prevention technique in Eritrea and its effect on the environment due to improper way of biofouling prevention and cleaning technique. This research paper is mainly taken in two places with the aid of internet the two places are Massawa ship yard and Massawa port. These are the places where more corroded hull and biofouling found. We have asked questions to the person working on board ship and various other persons working in port and Massawa Ship yard to know the technique applied to prevent biofouling and hull corrosion prevention technique. From the research paper we concluded that Corrosion inhibitors are substances that can be added to ship hull which decrease the rate of attack of that environment on a material such as metal. They can help extend the life of equipment, prevent system shutdowns and failures, avoid product contamination, prevent loss of heat transfer, and preserve an attractive appearance of structures. New types of paints mostly made of zinc/silicon which lasts long and minimize the corrosion of the steel can be used to prevent corrosion. In addition we can control corrosion by giving coatings on top of the paint. Polymers that are most successfully used for corrosion protective coatings are epoxy based materials; polyurethane based polymers, urethane topcoats over epoxy primers, some cross linked polyester materials, and some melamine cross linked polymers.Great precautions are not taken to protect a port from an invasive, non indigenous species if this entails widespread pollution of that port through heavy metals and a variety of toxic herbicides and pesticides. Other than we can give (Rubber coating) the small boats and yachts which generally made of fiberglass. For protection of the hull of the ship we can clean it at regular interval of time we can give zinc plating of the side of the hull of the ship made of steel to prevent corrosion and fouling taking place which are reasons for lose of steel thickness and ship’s speed. We can use tin free self polishing copolymer (SPC) which is basically designed to be smooth and rough so the biofouling seagrowth will be released from the hull rather than stick to it, and also will be easily cleaned. Compared to other countries the way of our hull corrosion and biofouling prevention technique is inadequate for the existence of our vessel. However improvement of preventing technique should be made rather than currently used for our vessel.

Thử nghiệm tự nhiên đánh giá hiệu quả chống hà đối với một số hệ sơn men của Liên bang Nga

This paper introduces the results of field testing antifouling effects of some kinds of enamel antifouling paints from Pigment and DEP companies at Marine Testing Station Dam Bay (Nha Trang Bay, Vietnam). It is found that the paint with the self-polishing copolymer and the low rate releasing paint of Pigment Company show good antifouling effects for over 6 months testing while the nonstick paint of DEP Company is not effective against fouling.

Surface Characteristics and Antifouling Performance of Inorganic MnOx- WO3-TiO2 Nanopowder for Self-polishing Copolymer Paint Applications

The nanoscale powders were synthesized by sol-gel method in order to prevent the biological fouling on the ships and offshore structures. Powder characteristics and antifouling performance were investigated with respect to the crystalline, microstructure and surface property for application in self-polishing copolymer resins. The high antifouling activity of -system biocide was attributed to its redox potential and soluble metal ions originating from tungsten oxides according to the improvements in the powder characteristics. Based on their physio-chemical characterizations, the specific surface areas of powders were about and the grain size was in the region 100 ~ 150 nm. Powder characteristics and surface properties were improved by the addition of . Antifouling performance were analyzed according to their surface properties and static immersion tests to determine the effects of the -system compounds. The surface of 2 wt. % added sample was clean for 5 month. This may be attributed to the ability of powders to act as a promoter in antifouling agents.

Micellar core-shell-type acrylic-polyurethane hybrid materials with self-polishing property

Marine fouling can be a serious problem in the shipping industry, since it increases the surface roughness of the hull and hence its frictional resistance to its movement through water. Antifouling paint can be defined as preventing the attachment of marine organisms onto surfaces. However, the most commonly used antifouling coating which is the tributyltin-based self-polishing copolymer causes the severe pollution of marine environment. Ammonium salt-based paints include tertiary amines as biocides which have effective biocidal and biodegradable properties without accumulation in the sea environment. However, ammonium salt-based coatings were too sensitive to seawater and became swollen. In this study, polyurethane-acrylic copolymers were synthesized by radical polymerization. These hybrid materials were found to form core–shell structures in aqueous media. Synthesis and properties of copolymers were investigated by Fourier transform-infrared spectrometer, proton-nuclear magnetic resonance, transmission electron microscopy, and dynamic light scattering. The polishing rate of self-polishing copolymer was determined from the reduction in dry film thickness after artificial seawater immersion under a dynamic condition.

Estimation of long-term drag performance of fouling control coatings using an ocean-placed raft with multiple dynamic rotors

An experimental setup was designed and built to estimate changes in the skin friction of fouling control coatings (FCC) over an extended period of time in conditions simulating the vast majority of ship profiles (regarding speed and activity) in the present market. The setup consisted of two separate parts: one aged FCCs directly in seawater in a dynamic manner by simulating the exposure condition of a ship’s hull, and a second, laboratory part measured the torque (drag) of aged coatings in a rotary setup. From the spring to the autumn of 2013 and 2014, four commercial FCCs were exposed for 53 weeks in Roskilde Fjord, Denmark, which is characterized by relatively cold seawater and a salinity of approximately 1.2 wt%. The in situ immersion seawater conditions consisted of five-week cycles divided into 2 weeks of static immersion and 3 weeks of dynamic immersion, during which time the cylinders were rotated at a tangential velocity of 8.1 knots. The skin friction was found to generally increase more during the static period, compared to the dynamic ones. Over the course of the entire exposure period, the skin friction of the investigated FCCs decreased in the following order: fluorinated fouling release coating (FRC) (highest skin friction), hydrogel-based FRC without biocides, silylated acrylate self-polishing copolymer coating, and hydrogel-based FRC with biocides (lowest skin friction). However, the differences in skin friction between the latter three coatings were minor and often within the range of experimental uncertainty. The average surface roughness of the FCCs in the newly applied and mechanically cleaned condition, determined as the Rt(50) and R z parameters, was evaluated as poor predictors of skin friction.