| Abstract: | To investigate high-pressure copolymerizations a sampling technique has been developed enabling continual on-line GLC analysis of the reaction mixture. As a result more reliable kinetic data are obtained. This new “sequential sampling” method, allowing the use of gaseous monomers, has been tested for the copolymerization of ethylene with vinyl propionate at 118 MPa and 335 K with tert-butyl alcohol as solvent. The results are compared with those obtained with the “quenching” method used so far, which yields compositional data on the reaction mixture before and after the high-pressure stage, only. It is shown that the “sequential sampling” method is the most adequate method of determining high-pressure monomer reactivity ratios. Furthermore, it is an important safety feature that the present procedure can be easily remote controlled. The present experimental method is neither restricted to copolymerization nor to gas-chromatographic analysis of the reaction mixture. |
