The importance of Chemical resistant coatings
Different coatings that are resistant to chemicals are protecting a broad range of structures such as storage tanks, oil and gas pipelines, water and wastewater pipes, bridges, ships and other facilities. The products become effective because of their resistance to aggressively corrosive environments, hot and cold temperature, curing capability, high abrasion resistance and compliance with environmental regulations on the emission of volatile organic compounds (VOCs). For end users, this means greater assurance in achieving the desired results within the budget.
Teflon PTFE as Chemical resistant coating
PTFE or polytetrafluoroethylene is a non-stick coating that has the highest operating temperature of any fluoroplastic with a low coefficient of friction, excellent abrasion resistance and good chemical resistance. FTPE is resistant to a broad spectrum of industrial chemicals but it should be tested for all possible combinations of chemicals to which the devices may come in contact with. Currently, the only chemicals that are known to cause damage to PTFE are elemental sodium and elemental alkali metals, fluorine and high concentrations of metal hydrides, amines and imines at temperatures of 260oC (500oF). There are general chemical resistance charts for PTFE resins but they are general guidelines that do not provide specific guarantees. It is always the end user’s responsibility to test compatibility to produce the best possible results.
Polyurethane coating as protection against corrosion
The properties of solid polyurethanes vary from the soft rubbery elastomers to the hard ceramic-like systems. Solid polyurethanes have chemical bonds that are highly cross-linked to each other to create hard and dense systems that have good chemical and mechanical resistance. Solid polyurethanes are the choice of many industries because they have excellent adhesion and provide good corrosion protection for metals. On the other hand, elastomers have more linear structures but with less cross-linking that allows them to be stretchy and elastic. Elastomers have greater impact strength and flexibility but they have poor adhesion and chemical resistance which makes them more suitable as coating for substrates that move and flex like concrete. However, the chemical resistance of elastomers can be improved if coating is applied more thickly.
Choosing the right Chemical resistant coatings is for lifetime protection and efficiency. For example, pipeline coatings are very critical in connecting these pipelines to end-users because they have to ensure that there is no corrosion and the integrity of the high-pressure carbon steel pipeline is maintained When selecting a suitable coating, it is important to consider the coating’s ability to provide chemical and mechanical protection as well as damage resistance from rough handling. It is also important to consider its compatibility with soil chemistry and pipeline operating temperatures.