# Environmentally Friendly Anticorrosive Polymeric Coatings
## 1 Introduction  
_Corrosion Cost and Environmental Impact_  
Corrosion is a universal topic, for many accepted as an inevitable process. The penalties of failures from corrosion are highly impactful from a human safety perspective and an economic point of view, including safety hazards or plant interruptions.  
The conclusion of significant studies undertaken by several countries was that corrosion represents a constant charge to the nation's gross national product (GDP). The National Association of Corrosion Engineers (NACE International) studied the role of corrosion management in industry and government impact in the US and estimated a global cost of corrosion of US $2.5 trillion, equivalent to 3.4% of US GDP, and from approximately 1 to 5 percent of GDP of each nation. These numbers are considered to be conservative since only well-documented costs can be used for study: corrosion control management as well as maintenance costs, monitoring, inspection and fewer failures are difficult to measure. Nevertheless, it was observed that indirect costs due to corrosion damage are often significantly greater than direct costs. Hence, the total cost which should include direct plus indirect cost could double the corrosion cost up to six percent of US GDP [1, 2].  
Health hazards and environmental impact of corroded materials, which could be considered as indirect costs, have been widely studied. Especially, the runoff of multiple metal ions (iron, zinc, lead, manganese) causing the contamination of the surrounding environment and drinking water systems were reported [3, 4, 5, 6, 7]. Moreover, the iron rustinfluence on the growth rate of Legionella bacteria [8], chemical emissions from cathodic protection of offshore wind farms (OWF) [9], or the environmental impact of rust removal techniques are other examples of environmental concerns [10].  
Anticorrosive polymeric coatings have gained high potential and flexibility against metal protection compared to non-polymeric ones, as they can be designed and formulated to achieve more than one protective mechanism. This review is focused on anticorrosive polymeric coatings, paying special attention on environmentally friendly solutions able to achieve a proper balance between cost, technical performance, and environmental issues.  
Therefore, the need to overcome the economic damages generated by corrosion phenomena has been faced through the development of several coating technologies. This review is focused on anticorrosive polymeric coatings as a flexible and effective solution against corrosion by means of different and simultaneous mechanisms of corrosion inhibition. A comprehensive vision of the topic is provided, together with a state of the art for eco-friendly polymeric coatings organized in four main categories, according to the polymer resin type: epoxy, polyester, polyurethane, and acrylic.  
Above all, the present work aims to give an overall picture on how the coating market is evolving as a response to the public, government, and consumers' commitment to sustainability. Special attention is paid to new trends in the anticorrosive coating field, as the scientific community is addressing the high demand for environmentally friendly coatings with innovative solutions. Moreover, a selection of applications is made to highlight the urgency of a proper balance between cost, technical performance, and environmental issues in the coating sector.