Accelerated degradation of cellulose acetate cigarette filters using controlled-release acid catalysis

Abstract

It is estimated that 6.3 trillion cigarettes will be consumed worldwide in 2010. A significant percentage of the used filters will be discarded improperly into the environment. Of the filter components, the plasticized cellulose acetate fibers have the slowest degradation rate (up to years). A rate-limiting step is the hydrolysis of cellulose acetate polymer into cellulose and acetic acid, which is extremely slow under ambient conditions. The hydrolysis rate is accelerated using the controlled release of acid. This release is achieved using encapsulated weak organic acid(s) with benign sulfate/phosphate esters. Encapsulation creates a barrier between the catalyst(s) and the cellulose acetate fibers in the filter. This coating protects the cigarette filter's integrity and function until it is smoked and discarded. Once discarded, the filter's encapsulation is breached by environmental water (rain, dew, etc.), which triggers the release of catalyst and then initiates hydrolysis.