South China University of Technology biodegradable polymer-based marine anti-fouling materials made a series of progress

Professor Zhang Guangzhao and Professor Ma Chunfeng of South China University of Technology have carried out a series of work on the topic of "marine anti-fouling materials" which is related to the major strategic needs of the country, put forward a new path of "degradation and anti-fouling" in the international community, developed a series of biodegradable polymer-based anti-fouling materials and were the first to succeed in marine experiments.
Figure 1: Map of the process of marine biodeface generation
In the field of biodegradable polymer-based anti-fouling materials, the team has designed and prepared biodegradable polyurethanes with excellent electrolytic properties and controlled degradation rates, main chain degradation-side chain hydrolytic polyurethanes and biodegradable polymer materials with anti-fouling function, etc., and the idea of "degradation and anti-fouling" has been highlighted by European coatings. The series of materials can be degraded by the main chain to continuously update the surface to achieve anti-fouling purposes, and because the degradation product is non-toxic small molecules, to avoid marine plastic pollution.
Figure 2: Biodegradable polymer-based anti-fouling material surface self-renewal schematic
In particular, in the new environmental protection self-polishing anti-fouling material research, the task force for the first time in the international preparation of the main chain degradation type self-polishing anti-fouling polymer (Ind. Eng. Chem. Res. 2015, 54, 9559; PCT International Patent: WO2015010390A1, U.S. Patent: US20160185913). The prepared poly (hexaester-co-methyl acrylates-co-trianyl silicone methyl acrylicate) has the characteristics of traditional polypropylene silica ester, i.e. stable hydrolytic rate, smooth surface after hydrolysing, etc., at the same time, it has a degradable main chain structure, which can effectively coordinate the hydrolytic properties of side-silane and the solubility of polymers.
Figure 3: The main chain-degraded acrylic silicane ester-based self-polished polymer structure
the material can still degrade at a constant rate in seawater, especially in static environments, to achieve the control release of anti-fouling agents. The material has excellent environmentally friendly and static anti-fouling properties. At present has completed 500 liter expansion trial production, and in a series of marine coatings companies to promote the use. Anti-fouling coating based on this resin has also achieved 3 years of ocean hanging board results, so as to meet the low-speed ships, submarines anti-fouling requirements, to solve the long-term monopoly of such materials by foreign countries to lay the foundation. At the same time, the achievement successfully broke through the existing self-polishing anti-fouling polymer synthesis and application technology, for the development of a new type of Wuxi self-polishing anti-fouling materials with independent intellectual property rights, accelerate the development of anti-fouling technology in China's ships has a driving role and important economic significance.
figure 4: Biodegradable polymer-based self-polishing resin expansion production (500 kg class), marine experiments (left for control samples, right for biodegradable polymer-based anti-fouling coating) and solid ship coating
It is hoped that by suppressing biological defacement at the source, but the material has limited anti-fouling capacity in the ocean, it is found that due to the complexity of the marine environment and the diversity of defaced organisms, its wide-spectrum resistance is poor, which has no effect on some large marine defaced organisms; Therefore, the use of this type of material alone has great limitations. Although defaced impedance materials have demonstrated anti-fouling capabilities for a variety of marine bio-larvae in indoor anti-fouling experiments, no successful marine hanging plate experiments have been reported.
In the study of defleated coating material, the team attached triclosan malaylamide to PDMS-based polyurethane, which has excellent anti-bacterial, diatom and barnacle larvae, while hydrophobic anti-fouling agents ensure the properties of low surface energy of PDMS, and the dual functional effect gives the material a good solid sea anti-fouling effect. Defaced de-attached coating anti-fouling performance is good, preparation process is relatively simple and cost-controllable, there are now commercial products, accounting for about 6% of the market share, and in combination with other anti-fouling means to improve its static conditions anti-fouling capacity, it will be more applications.
In the study of bionic anti-fouling materials, the surfaces of many marine organisms (sharks, dolphins, some momals, etc.) are virtually non-parasitic to other organisms, and although the exact structure is not yet known, their anti-fouling properties are generally thought to be related to the surface microstructits, bioactive molecules, surface self-shedding, secreted mucus and hydrolyzed enzymes. The anti-fouling structure of biodegradable polymer-based materials proposed by the research group is similar to this, and its surface is self-renewing in the middle layer of seawater, which drives the defaced organisms to fall off, and the "skin velocity" is stable and controllable. The author thinks that it is the best way to combine biodegradable polymer with environmentally friendly anti-fouling agent to form an efficient, environment-friendly and multi-functional marine anti-fouling system. In the marine environment, the system can mimic the surface of marine life or seaweed plants can secrete biologically active substances and surface self-shedding characteristics, play the dual role of anti-biological attachment and surface self-renewal, so as to achieve long-term collaborative anti-fouling purposes.
the marine environment is extremely complex and rich in biodiversity, it seems that marine pollution prevention cannot rely on a single approach, integrated pollution prevention is the focus of future research. For example: the defacement and defacement impedance material binding, biodegradation polymer and natural anti-fouling agent combination, main chain degradation and defacement impedance material binding, and so on. Therefore, with the enhancement of human environmental awareness and the improvement of laws and regulations, efficient and environment-friendly marine anti-fouling materials have undoubtedly become the focus of development.。