Styrene Maleic Anhydride Polymers
Low molecular weight styrene maleic anhydride (SMA) polymers and polymers based on SMA have been utilized as binders for fibrous materials. These low molecular weight SMA resins are generally synthesized via free radical polymerization of styrene with maleic anhydride in a solvent such as cumene that acts as a chain transfer agent. The initiators of choice are peroxides and hydroperoxides such as cumene hydroperoxide, CHP. During synthesis of SMA, CHP can generate acetophenone as a by-product. Presence of the solvent cumene and CHP as contaminants in the final product (SMA) is undesirable. Their presence can create an undesirable color. Manufacturers attempts to remove these impurities, however by flash drying and vacuum drying SMA, has not been enough to eliminate the odor problem.
Recent US Patents
11/2/2010
7,825,214
Purified styrene-maleic anhydride polymer binder
Shooshtari and Asrar of Johns Manville, Colorado have developed an aqueous binder based on a polyanhydride. The resulting binder is effective, particularly for binding glass fibers, yet substantially odor free. Such bound fibrous material is free of a phenol-formaldehyde resin and substantially free of odor. It has been found that by removing purities such as cumene and acetophenone from a polyanhydride binder, e.g., a styrene maleic anhydride based polymer based binder, an effective binder for glass fiber is obtained while also avoiding an odor problem. (RDC 3/2/2011)