API-221F will crosslink at ambient temperature to form a topical polymeric film with chemical anchors that have penetrated into the substrate. Upon application its reactive oligomers and polymers penetrate into the composite at different rates. The oligomers and lower-molecular-weight polymers form covalent bonds with the wood fiber. A "sequential" curing process creates an interconnected, three-dimensional network, which can then crosslink with the higher-molecular-weight surface polymers. After fully curing, the result is a high-tensile-strength, densely crosslinked, transparent topical polymeric film with chemical "anchors" that have penetrated into the substrate.

The resultant clear-coating film resists staining from foods, wine, oil, grease, and moisture, and the supplier says it is durable. Some staining can be removed with cleaning, but others leave residual color. API-221F is designed to protect the decking material to overcome this deficiency.
 
In answer to a query from MPW, Laura Kushner, new business development manager at 
Advanced Polymer, says the product should work on both polyolefin- and PVC-based decking materials. Although the company’s target market is companies formulating for contractors and for the do-it-yourself (DIY) market, she also thinks the material likely could be applied online as part of an extrusion operation. However, the temperature of the surface to be coated should be 50ºF–85ºF.  Dry-to-touch time is 15-25 minutes.

In development and testing efforts, the product was applied by spray or roller, Kushner adds. One gallon of formulated API-221F will cover 100- 200 ft², depending on composite surface properties. —[email protected]