Graft Copolymerization onto Cellulose Acetate and Wood Using Anionic Polymerization

Abstract

The grafting of synthetic polymers to natural polymers from renewable resources offers the potential of preparing newer varieties of engineering materials with specific and improved properties for a wide range of applications. The properties of this molecular composite would be substantially better than the properties of either homopolymer alone. If the individual polymer segments in copolymers have opposite properties such as polar and nonpolar and/or flexible and rigid natures, many interesting properties are conceivable. For example, if an amorphous polymer like polystyrene is grafted onto cellulose, a molecular composite will be produced, where the stiff cellulose chain is a reinforcing fiber in a polystyrene matrix. The mechanical properties of this molecular composite would be substantially better than the properties of either homopolymer alone. The stiffness of the cellulose chain can be controlled by chemical modification prior to grafting, and the mechanical properties of the grafted polymer can be engineered by controlling the chemical composition and molecular weight of the graft. Thus, we can make materials with fibers of controlled stiffness covalently bound in a polymer matrix, where the matrix mechanical properties can be varied from a rubber to a hard glassy polymer. However, it is impossible to predict exactly what the mechanical properties of these polymers will be until these systems are synthesized and tested.