Bio-renewable vinyl monomers for the synthesis of acrylic copolymers
摘要
Acrylic copolymers have myriad uses in both architectural and industrial coatings. Waterborne acrylic emulsions are employed for exterior and interior architectural finishes with minimal volatile organic compound (VOC) content. However, there are still solvent-based coatings for industrial and automotive applications which result in a considerable amount of VOC. Environmental regulations to control the amount of VOC from coatings are getting stringent in most countries. Researchers across the globe are working toward reducing the VOC by either using high-solid resins or moving toward waterborne resins. The monomers employed for synthesizing acrylic resins come from petroleum, a non-renewable fossil fuel. To reduce fossil fuel consumption, efforts have been made to use greener raw materials in the polymer synthesis. Replacement of petroleum-based acrylic monomers with greener raw materials is difficult because each acrylic monomer brings a specific structure–property relationship to the polymer synthesized. Furthermore, using alternative green sources and renewable monomers brings new challenges as the synthesized resin must be compatible with solvents, additives, and pigments and meets the required properties of the acrylic coatings. In the literature, the usage of different bio-sources-based green alternatives of acrylic monomers like hydroxyl ethyl methacrylate, methyl methacrylate, butyl acrylate, methacrylic acid, and acrylic acid has been reported. As styrene is part of most acrylic resin formulations, the bio-sources of styrene and its green alternatives have also been mentioned. The alternate green monomers and their potential use in coatings’ field are also explored. A short perspective on whether green monomers and renewable sources for acrylic monomers can be commercially used to produce coatings for various applications is also discussed.
Graphical abstract