2-Ethylhexyl acrylate
A very soft, water-resistant acrylic monomer used in elastomeric roof coatings, sealants and pressure-sensitive adhesives.
2-Ethylhexyl acrylate is the ester of acrylic acid with branched 2-ethylhexanol (molecular weight about 184.3 g/mol). Its homopolymer has a very low glass transition temperature, roughly −50 to −65 °C depending on the source.
2-EHA is used in acrylic copolymers that must stay flexible in cold weather and resist water: elastomeric roof coatings, caulks and sealants, and pressure-sensitive adhesives for tapes and labels.
Its long branched side chain is hydrophobic and keeps polymer chains apart, lowering Tg and improving water resistance. Polymerization is by free radicals, usually as part of a copolymer with harder monomers.
Monomeric 2-EHA is an irritant and skin sensitizer. Store inhibited monomer with air in the headspace and away from heat to prevent unwanted polymerization.
Both are soft monomers. 2-EHA gives an even lower Tg and better water resistance, while BA is more common in general-purpose latex paints.
It keeps films flexible in cold temperatures and helps them shed water, both important for elastomeric roof membranes.
