“Block-random” copolymers as stabilizers in emulsion polymerization

Industry Partners: Dr. Sean George (BASF, USA), Dr. Crispin Amiri and Andreas Gernandt (BASF, Germany)

Water-based coatings, sealants, paints and adhesives are environmentally friendly alternatives to solvent-based products, with lower toxicity, fewer harmful emissions to the environment and reduced risk to humans by exposure to harmful vapors. Despite their significant advantages compared to solvent-based products, water-based latexes are not without their concerns. One of the issues is the tendency for the “surfactant” or “stabilizer” (an essential component of the product that plays a critical role in ensuring the latexes exist as discrete particles suspended in water) to migrate out of the latex. The surfactant can end up in the environment if for example the product is an exterior paint, or it could result in human exposure if the product is for example an adhesive on produce labels. BASF, a global company with significant manufacturing operations in Canada is collaborating with our research group to develop a new type of stabilizer with the objective of overcoming deficiencies of existing stabilizer materials. The key to this research is the design of specially designed molecules that are much larger than traditional surfactants or soaps; one end of the molecule will strongly adhere to the particles, thereby preventing their migration to the environment. At the same time, the other end of the molecule or polymer chain, will have to fulfill a demanding set of properties to ensure the product can be manufactured safely and economically. Queen’s and BASF researchers have designed a novel structure that meets these requirements, and will now seek to better understand their fundamental behaviour and properties. Our research will help industry address challenges in new product innovation, and develop new innovative products with reduced environmental impact.

A combination of the block copolymer structure with that of the commercial random copolymers (alkali-soluble resins) produces a block-random copolymer.