Acrylic polymer emulsions are one of the great success stories of modern industrial chemistry. The science behind this versatile class of polymers was perfected just after World War II, driven by an unprecedented housing boom and the demand for more versatile, more efficient paints. The result was household acrylic paint, an aqueous technology that required less preparation to use, was easier to clean up, had less odor, and performed better than paints made with solvents.
Today, acrylic acid remains an essential building block in the production of some of our most commonly used industrial and consumer products. Approximately two-thirds of the U.S. supply of acrylic acid is used to produce the acrylic esters methyl acrylate, butyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate. Taken together, acrylic acid and its esters are known as acrylates, and they are used as ingredients in a wide variety of products, including paints, coatings, textiles, adhesives and plastics.
The versatility of acrylic polymers is made possible by the number of building blocks available for polymer synthesis, as well as diverse ester functionality. Chemists select appropriate hard and soft monomers in order to build acrylic polymers with specific attributes for a variety of end-use applications. Pure acrylic polymers are also possible, resulting in polyacrylic acid or crosslinked polyacrylic acid compounds, which are used in the manufacture of hygienic products, detergents, and water purification and wastewater treatment.
As previously discussed, acrylic resins offer a significant advantage as ingredients in latex paint. They provide greater resistance to blistering and cracking, are extremely waterproof and can last for decades without yellowing when exposed to UV light. As chemists tweak their formulas, they can increase the desirable properties of the paint. Today’s latex paints often deliver enhanced dirt pick-up resistance, superior gloss and excellent color retention, all while providing long-lasting wood protection against the effects of weathering damage.
But acrylic polymers have a number of other practical applications beyond paints. Acrylic polymers are commonly used in pressure-sensitive adhesives (PSAs), which rely on subtle pressure to create a bond. Applying this pressure enables the adhesive to “wet out” — to flow and cover a substrate to maximize the contact area and the attractive forces between the adhesive and bonding surface. For an adhesive to effectively wet out a surface, the surface energy of the adhesive must be as low or lower than the surface energy of the substrate to be bonded. In addition to surface energy, the usual tack, peel and shear properties must also be considered. PSAs are found in a number of applications, from shipping labels to foam insulating tape to laminating adhesives.
The construction industry has also found great success modifying Portland cement with acrylic-based polymers. The polymers improve several functional attributes of the cement, including adhesion to the old surface, flexural strength, tensile strength, and freeze/thaw durability. They also reduce permeability, halt the intrusion of chlorides and increase abrasion resistance. Acrylics and styrene-acrylics as well as styrene-butadiene polymers are used in applications involving cement.
Finally, acrylic emulsion polymers products are important components for graphic arts and barrier coatings applications. Acrylic emulsion polymers are readily formulated into overprint varnishes and inks to impart water resistance, rub resistance, alkaline resistance, and high gloss. They also can be incorporated into barrier coatings for paper and paperboard products, improving oil, grease and water resistance.
Mallard Creek Polymers can work with you to find an existing acrylic polymer that fits your end use — or develop a new one. Check out our Guide to Tailoring an Emulsion Polymer Recipe or contact us today to discuss what we can make for you.