2 research outputs found
Analytical Solution of Free Radical Polymerization: Derivation and Validation
An
elegant, simple, and exact analytical solution (AS) was obtained
for a large range of elementary steps with practical importance in
free radical polymerization. The AS matches excellently with the numerical
solution for the four cases of monomer–polymer systems studied
ranging from the slowest to the fastest. It works equally well for
different initiators, different initiator and monomer concentrations,
presence or absence of solvent, various solvent volume fractions,
and different temperatures. It also matches quite well with experimental
data reported in the literature. This AS is not only in line with
previous published solutions but also extends their applicability
in a natural way. Overall, the conceptual correctness as well as predictive
capabilities of the derived AS are established beyond doubt. This
AS has the potential to be used in various practical applications
such as model based process control, CFD simulations, and so forth
Coil Flow Inversion as a Route To Control Polymerization in Microreactors
Linear and branched polymers of 2-(dimethylamino)ethyl
methacrylate
(PDMAEMA) were synthesized in flow by atom transfer radical polymerization
(ATRP) and self-condensing vinyl copolymerization adapted to ATRP,
respectively, in capillary type stainless steel coiled tube (CT) microreactors.
Coil flow inversion (CFI) was introduced to achieve better mixing
and narrower residence time distributions during polymerization. This
strategy was adopted to improve control over macromolecular characteristics
and polymer architecture. Polydispersity index (PDI), as an overall
indicator of control over polymerization, was significantly lower
for CFI in the case of linear PDMAEMA, 1.39 compared to 1.53 for CT.
For branched polymers containing up to 10 mol % of inimer, a reduced
PDI was also obtained for CFI microreactor. As for the branching efficiency,
it was found to follow the following trend CFI > CT > batch
reactor