Study of Sulphonation Processes of the Expanded Polystyrene waste and Properties of the Obtained Products

摘要

1.Introduction More and more attention is paid to polymer wastes recycling due to their hazard to the environment. Chemical modification can be one of the ways of effective waste management. Products with an incorporated sulphonic group via sulphonation exhibit increased strength, hydrophilicity and proton conductivity. These features have led to a variety of applications of sulphonated polymers such as batteries, sensors, displays, ion-exchange resins and polyelectrolytes. Among the known methods of polystyrene sulphonation the sulphonation under heterogeneous conditions seems to be the most profitable. Therefore we applied Neihoff method of sulphonation to convert polystyrene waste into a polymeric water soluble flocculent[1]. These sulphonated derivatives usually fred application in the industrial water treatment due to the several times lower consumption of coagulants, shorter flocculation time and improved sedimentation properties of suspensions. However the Neihof method of sulphonation requires the usage of a significant excess of sulphuric acid in proportion to the polymer constitutional unit. Also, the separation of the products from the acid is a difficult and energy consuming process. In order to decrease the environmental hazard of the reaction and to increase its economy we decided to study the usefulness of the silica sulphuric acid in the polystyrene sulphonation reaction. Using this sulphonating agent we wanted to obtain products with properties of cation-exchange resin.