Macromol. React. Eng. 7/2009

Summary: The use of very hydrophobic monomers in heterogeneous polymerisations is restricted because of insufficient mass transfer as a result of limited aqueous phase diffusion. Experimental evidence for a mass transfer mechanism in miniemulsion polymerisation that is based on the direct interaction between droplets as well as between droplets and particles ('collisions') rather than monomer diffusion is presented. Mass transfer that results in the formation of a copolymer in the miniemulsion polymerisation of a mixture of lauryl methacrylate and 4-tertbutyl styrene, is almost non-existing when physical contact between individual droplets is prevented by a membrane. However, monomer transport by diffusion is observed in reference experiments with more hydrophilic monomers.

Section: Resultsmentioning

confidence: 99%

Mass Transfer in Miniemulsion Polymerisation

Jansen

Lovell

Meuldijk

et al. 2013

“…As one could expect, the situation is even worse in heterogeneous processes. For instance, in the context of polyolefin reactor modeling, Soares et al wrote: “until a more quantitative understanding of polymerization kinetics steps, particle fragmentation and growth (…) is achieved, the integration of all these phenomena in a single reactor model may be viewed as a stimulating academic exercise but will hardly lead to mathematical models with improved predictive capabilities.” In emulsion (co)polymerization too the challenges are significant, especially in the fields of particle nucleation (primary and secondary), particle aggregation and radical entry/exit . Of course, the list could go on.…”

Section: Preparing For the Futurementioning

confidence: 99%

“…In emulsion (co)polymerization too the challenges are significant, especially in the fields of particle nucleation (primary and secondary), particle aggregation and radical entry/ exit. [16][17][18][19][20][21] Of course, the list could go on.…”

Section: Preparing For the Futurementioning

confidence: 99%

Models in the Polymer Industry: What Present? What Future?

Vale

Daiss

Naeem

et al. 2013

Summary An industrial perspective on the present and future role of kinetic and process models in the polymer industry is presented. A number of selected examples illustrate the current value of model‐based approaches in supporting and accelerating tasks like process optimization, product development and design of polymerization reactors. In addition, future trends for the application of models in the polymer industry are discussed and areas where further improvement is thought to be needed are carefully underlined.

“…Mass transfer rates between immiscible liquids play an important role in heterogeneous reaction systems such as emulsion polymerizations 1. They could become rate or quality determinant, considering the loss of kinetic control in the context of process intensification.…”

Section: Introductionmentioning

confidence: 99%

Effect of Sodium dodecyl sulfate on the Mass Transfer Rate between Styrene and Water

Katzer

Pauer

Moritz

2011

Summary: The effect of sodium dodecyl sulfate (SDS) on the mass transfer rate between styrene and water has been investigated. SDS increases the solubility of styrene in water even below the critical micelle concentration (CMC) and therefore increases the thermodynamic driving force for the mass transfer. The mass transfer coefficient however is not altered by SDS, even if the interface is almost saturated with emulsifier.