(98ai) Encapsulation of Anti-Traction Material to Maintain Water Content

                                        Encapsulation of Anti-Traction Material to Maintain Water Content

Brian Zukas and Nivedita Gupta

Department of Chemical Engineering

University of New Hampshire, Durham, NH

An aqueous high concentration polymer solution has been proven effective as an anti-traction material (ATM).  The anti-traction property however is highly dependent on the water content of the solution.  Using emulsion polymerization, the ATM material will be encapsulated in a semi-impermeable encapsulant to increase the time over which the material remains effective regardless of the external environment.  An effective encapsulant will prevent water loss over a wide range of temperatures, allow for the encapsulation of a large volume of material relative to the capsule shell thickness, and rupture easily under foot pressure.  Different polymer shell materials, reaction times, and additives are tested to determine the optimum conditions for encapsulation.  Water permeability of the capsule shell is measured by monitoring osmotic swelling of the capsule in an aqueous solution.  The minimum force to rupture the capsule shell is measured as a function of reaction parameters and shell thickness.  The capsules’ carrying capacity of anti-traction material will be evaluated in conjunction with the force required to rupture the shell.