New work on Plant-based coatings

An Indian research group at the Institute of Chemical Technology in Mumbai has been working on developing environmentally friendly polyurethane coatings in a recently completed project. The background is the worldwide increase in demand for innovative technologies to conserve resources and reduce emissions in industrial coatings.Various vegetable oils and their derivatives such as methyl esters, fatty acids and other renewable raw materials served as the basis for the polyurethanes.

Alternative coatings material

The advantages of these „green“ alternatives are that they are easily available, biodegradable, inexpensive and have a low environmental impact. The scientists developed various methods to convert the raw materials into the desired polyols and isocyanates. In addition, the focus was on the production of various PUR coatings and the investigation of possible application processes. possible application methods. One example was the synthesis of polyester polyols through catalytic epoxidation of soybean oil, followed by a ring-opening reaction using bio-based oleic acid.

The polyurethane coating was produced by reacting the polyols produced with hexamethylene diisocyanate in dipentene as a biogenic solvent. In order to ensure the applicability of the coatings produced in this way in the coatings industry, extensive tests of the surface properties were carried out and compared with those of conventional, petroleum-based polyurethane coatings.

Coatings with good properties

Analytical techniques such as FTIR spectroscopy and nuclear magnetic resonance spectroscopy were used to elucidate the structure of the epoxidised soybean oil and the polyester polyols. As a result, it was found that the surfaces of the bio-polyurethanes had very good optical and mechanical properties – comparable to those of conventional PUR coatings – as well as higher corrosion resistance.

More information: www.ictmumbai.edu.in