| Abstract: | Silylation of poly(vinyl alcohol) and cellulose with hexamethyldisilazane (HMDS) in a twin screw extruder using ammonia as reaction medium has been studied. As the starting materials are powders which do not melt without decomposition both polymers were blended with the corresponding trimethylsilyl polymer and a reaction compartment was created using appropriate restrictor elements. Reaction profiles with temperatures below 100°C in the reaction zone and lower temperature in the restrictor zones enabled silylation of both polymers. Residence times were as low as 15 min. |
