Lignin-based coatings: A novel approach to turn challenges into opportunities for anti-corrosion and anti-wear applications

可持续发展是一个至关重要的概念，它认识到我们这个星球有限的资源，以及人类在生态系统中的地位。为了实现一个可行和持久的环境，必须用最少的能源消耗和利用可再生资源生产材料。材料还应具有良好的耐久性，而腐蚀和磨损造成的磨损往往是限制因素。在这个项目中，我们的目标是用可再生材料生产耐用涂料，这种涂料不仅本身是可持续的，而且还能保护底层材料免受腐蚀和磨损。腐蚀是一个主要问题，它会导致巨大的经济成本，在最糟糕的情况下，甚至会在结构倒塌时造成人员伤亡。全球使用的传统防腐方法往往是有效的，但它们也有缺点。基于化石的涂料涉及二氧化碳排放，使用有害的防腐化学品会对环境和人类健康造成严重破坏。正因为如此，立法变得更加严格，许多最有害和最有效的防腐化学品现在都被禁止了。不幸的是，仍缺少性能相当的替代产品。禁止使用有害化学品是好的，但材料磨损更快的事实不利于可持续发展。迫切需要找到至少和违禁材料一样有效的可再生替代品。这个项目将使我们更接近这一目标。在这个项目中，我们将利用可再生生物质，从而为将生物质用于增值产品的努力做出贡献，这本身就是一个不断增长的研究领域。木质素是我们涂料中的关键成分，是最丰富的植物资源之一，林业和农业中的木质素资源过剩。今天，木质素主要是通过燃烧来补充能量。木质素没有被广泛利用的原因是由于它的大而复杂的分子结构，高度抵抗解聚。解聚通常是制造有价值的材料所必需的，但对于我们打算生产的涂料来说却不是必需的，因为木质素的大而交联的分子链对阻隔型涂料是有益的。防腐涂料的开发和生产主要是创造一种表面阻隔膜。然而，木质素是一种典型的劣质薄膜聚合物，这是这个项目的挑战。PI找到了一个聪明的解决方案来解决这个挑战，灵感来自蓝色贻贝。贻贝几乎能够牢固地附着在每一种材料上，如木材、钢铁、蜡，甚至特氟龙。秘诀在于贻贝特殊的蛋白质粘合剂。通过混合木质素和贻贝蛋白，我们可以在金属表面形成具有优异防腐和耐磨性能的保护膜。研究发现，贻贝蛋白膜也具有自我修复能力，这意味着涂层的轻微损伤可以自行愈合。市场上还有其他涂层可以在磨损时自我修复，但往往缺乏防腐功能。另一方面，现有的防腐涂层通常不能自我修复。我们将开发一种环保涂层，以减少腐蚀和磨损，从而延长底层材料的使用寿命。该涂料还可以与其他涂料结合使用，以实现额外的功能，甚至更好的耐用性。该项目有可能在涂料行业创造一种范式转变，增加对生物质的使用，以取代以化石为基础的、对健康有害和对环境有害的产品。

Sustainable development is a crucial concept that recognizes our planet's limited resources, and humans' place in the ecological system. To achieve a viable and lasting environment, it is essential to produce materials with the least energy consumption and from renewable resources. The materials should also have good durability, where wear due to corrosion and abrasion is often the limiting factor. In this project, we aim to produce durable coatings from renewable materials that not only are sustainable themselves but also protect the underlying material from corrosion and wear.Corrosion is a major problem that leads to enormous economic costs and in the worst case, even to personal injury and fatalities when structures collapse. The traditional corrosion protection methods used globally are often effective, but they have disadvantages. Fossil-based coatings involve CO2 emissions, and the use of harmful corrosion protection chemicals causes serious damage to the environment and human health. Due to this, legislation has become stricter, and many of the most harmful and effective corrosion protection chemicals are now banned. Unfortunately, alternatives with comparable performance are still missing. The ban on using harmful chemicals is good, but the fact that materials wear out more quickly is detrimental to sustainable development. It is an urgent need to find renewable alternatives that work at least as well as the banned materials. This project will take us a few steps closer to that goal.In this project, we will utilise renewable biomass, and thereby also contribute to the effort to use biomass for value-added products, which in itself is a growing research area. Lignin, the key component in our coating, is one of the most abundant resources in plants that there is a surplus of from the forestry and agricultural industries. Today, lignin is mostly used as an energy supplement through burning. The reason for lignin not being widely utilised is due to its large and complex molecular structure that is highly resistant to depolymerisation. Depolymerisation is often a necessity to create valuable materials, but is not needed for the coatings we intend to produce, because the large and cross-linked molecular chains of lignin will be beneficial for barrier-type coatings. The development and production of corrosion-protective coatings are mainly about creating a surface barrier film. However, lignin is a typically poor film polymer, which is the challenge of this project.The PI has found a smart solution to the challenge inspired by the blue mussel. Mussels are capable of firmly attaching themselves to virtually every material such as wood, steel, wax, and even Teflon. The secret lies in the mussel's special protein-based adhesive. By mixing lignin and mussel protein, we can create protective coatings on metallic surfaces with excellent corrosion protection properties and abrasion protective properties. It has been found that mussel protein films also have a self-healing ability, which means that minor damage to the coating can heal on its own. There are other coatings on the market that are self-healing in the event of wear, but often lack the corrosion protection function. The available corrosion protective coatings, on the other hand, are usually not self-healing. The proposed coating combines self-healing, corrosion protection and abrasion protection properties.We will develop an environmentally friendly coating to reduce corrosion and wear, which would increase the underlying material's lifespan. The coating can also be used in combination with other coatings to achieve additional functions and even better durability. The project has the potential to create a paradigm shift in the coating industry with increased use of biomass to replace fossil-based, health-hazardous, and environmentally harmful products.