| This dissertation describes the comparison of different continuous mixing machines as reactive extruders. The machines considered were a Kobelco Nex-T continuous mixer, non-intermeshing modular counter-rotating twin screw extruder as well as intermeshing modular co-rotating and intermeshing modular counter-rotating twin screw extruders.; Residence time distributions were measured for different continuous mixing machines using polypropylene with aluminum flakes as a marker. Various screw speeds and feed rates were considered.; The grafting reaction of maleic anhydride onto polypropylene and degradation of polypropylene during the grafting reaction were investigated as means for comparing of different machines for reactive extrusion. The influence of processing variables such as screw speed and processing temperature on polymer characteristics was investigated.; Generally, in comparison of the different machines, the intermeshing counter-rotating twin screw extruder has the shortest mean residence times and lowest levels of grafted maleic anhydride, while the Kobelco Nex-T continuous mixer has the longest residence times and highest levels of grafted maleic anhydride.; Associated with experimental studies of grafting reactions, mathematical models of maleation of polypropylene for different continuous mixing machines were also developed. The simulations included the effects of screw speed and feed rate for the four different continuous mixing machines. |
