| The molecular weight (MW) and molecular weight distribution (MWD) of polymers are extremely important properties because many end-use properties are a function of the polymer's MW and MWD.;In emulsion systems the heterogeneity of the system complicates the process. In this work the validity of integrating a kinetic model, proposed by Gilbert et al. (1995), and a diffusion model describing the transport of a chain-transfer agent (CTA) under conditions of diffusion limited chain transfer, (Nomura et al., 1994), in order to generate molecular weight predictions has been investigated. The technology exists to obtain accurate estimates of the required model parameters through techniques that make this approach amenable to on-line application.;A series of styrene emulsion polymerizations were carried out with varying levels of CTA, surfactant, and initiator.;The results showed that our approach provides a reasonable estimate of the product's weight average molecular weight and molecular weight distribution, even under conditions of severely diffusion limited chain transfer. (Abstract shortened by UMI.)... |
