| Abstract: | In order to evaluate copolymerization rates from dilatometric measurements, the relationship between volume contraction and conversion (dilatometric constant) must be investigated. This can be done gravimetrically or by means of density measurements. In cases where one of the monomers is not able to homopolymerize, both methods lead to different values. Equations necessary for this evaluation were derived and verified in the systems diethyl maleate-methyl methacrylate and diethyl maleate-styrene. In some cases, the dependence of the dilatometric constant on feed composition may be predicted taking into account the contributions to volume contraction of the different bond types present in the copolymer. An expression was derived for describing this dependence in cases where one of the monomers does not homopolymerize. Its validity for the system diethyl maleate-styrene was experimentally verified. |
