Propagation of the caprolactam polymerization wave

Volpert, Vladimir A.; Megrabova, I. N.; Davtyan, S. P.; Begishev, V. P.

doi:10.1007/bf01463417

Cited by 19 publications

(13 citation statements)

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“…Volpert and coworkers investigated this two-wave system. 50 Second, a "hot spot" moved around the front as it propagated down the tube, leaving a spiral pattern in the product. The entire front propagated with a velocity on the order of 0.5 cm/min, which was a function of the concentrations of activator and catalyst.…”

Section: Periodic Modesmentioning

confidence: 99%

Self Organization in Synthetic Polymeric Systems

POJMAN

1999

Annals of the New York Academy of Sciences

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Section: Periodic Modesmentioning

confidence: 99%

Self Organization in Synthetic Polymeric Systems

POJMAN

1999

Annals of the New York Academy of Sciences

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“…[33][34][35] However, relatively few experimental investigations have focused specifically on periodic and aperiodic fronts during frontal polymerization. Although spin modes were observed in the anionic polymerization of ⑀-caprolactam 36,37 and a subsequent stability analysis done by Volpert and Volpert, 38 the system has a disadvantage in that the front does not have a constant velocity because of homogeneous polymerization that occurs at the elevated temperatures ͑350 K͒ necessary to sustain a front. The first true spin mode for a system with a constant front velocity was reported by Pojman et al 39 They showed that at an initial temperature of 0°C, the frontal methacrylic acid polymerization exhibits spin modes.…”

Section: Introductionmentioning

confidence: 99%

Period-doubling behavior in frontal polymerization of multifunctional acrylates

Masere

Stewart

Meehan

et al. 1999

Chaos: An Interdisciplinary Journal of Nonlinear Science

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Front dynamics in the frontal polymerization of two multifunctional acrylate monomers, 1,6-hexanediol diacrylate (HDDA) and trimethylolpropane ethoxylate triacrylate (TMPTA), with Lupersol 231 [1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane] as the initiator, are studied. In most frontal polymerization systems, the dynamics are associated with a planar front propagating through the sample. However, in some cases, front behavior can be altered: the front becomes nonplanar characterized by complex patterns like spin modes and pulsations. To determine how these periodic and aperiodic modes arise, reactant solutions consisting of HDDA diluted with diethyl phthalate (DEP) and TMPTA diluted with dimethyl sulfoxide (DMSO) were used in the study. In the study we reveal frontal behavior characteristic of period-doubling behavior, a doubling of spin heads that degenerate into an apparently chaotic mode. Also, a pulsating symmetric mode has been observed. These observations have a striking similarity to observations made in studies of self-propagating high-temperature synthesis (SHS) in which the addition of an inert diluent afforded a rich variety of dynamical behavior. The degree of cross-linking has also been found to be a bifurcation parameter. The energy of activation of multifunctional acrylate polymerization is a strong function of the degree of polymerization. By adding a monoacrylate (benzyl acrylate: BzAc), such that the front temperature was invariant, we observed a period-doubling bifurcation sequence through changes in the energy of activation, which has not been previously reported. (c) 1999 American Institute of Physics.

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“…This paper continues the series of works where we study the stability of polymerization fronts and compare the theory with the experiments. [6][7][8]10,29,[41][42][43][44][45][46][47] The contents of the paper are as follows. In the next section we present the mathematical model and the results of linear stability analysis in a short form sufficient for further comparison with experimental results.…”

Section: Introductionmentioning

confidence: 99%

The effect of convection on a propagating front with a liquid product: Comparison of theory and experiments

McCaughey

Pojman

Simmons

et al. 1998

Chaos: An Interdisciplinary Journal of Nonlinear Science

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This work is devoted to the investigation of propagating polymerization fronts converting a liquid monomer into a liquid polymer. We consider a simplified mathematical model which consists of the heat equation and equation for the depth of conversion for one-step chemical reaction and of the Navier-Stokes equations under the Boussinesq approximation. We fulfill the linear stability analysis of the stationary propagating front and find conditions of convective and thermal instabilities. We show that convection can occur not only for ascending fronts but also for descending fronts. Though in the latter case the exothermic chemical reaction heats the cold monomer from above, the instability appears and can be explained by the interaction of chemical reaction with hydrodynamics. Hydrodynamics changes also conditions of the thermal instability. The front propagating upwards becomes less stable than without convection, the front propagating downwards more stable. The theoretical results are compared with experiments. The experimentally measured stability boundary for polymerization of benzyl acrylate in dimethyl formamide is well approximated by the theoretical stability boundary. (c) 1998 American Institute of Physics.

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Propagation of the caprolactam polymerization wave

Cited by 19 publications

References 1 publication

Self Organization in Synthetic Polymeric Systems

Self Organization in Synthetic Polymeric Systems

Period-doubling behavior in frontal polymerization of multifunctional acrylates

The effect of convection on a propagating front with a liquid product: Comparison of theory and experiments

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