Network formation IV. The nature of the termination reaction in free-radical polymerization

Multiscale Modeling of Branch Length in Butyl Acrylate Solution Polymerization

“…[20,21] The rate constants used in the model are given in [16] decompose to form two initiator radicals:…”

Multiscale Modeling of Branch Length in Butyl Acrylate Solution Polymerization: Molecular Versus Continuum Kinetics

“…The set of reactions used in the well-mixed KMC simulation, listed in Table 1, is the same as that used by Nikitin et al, [6] with the exception that combination of radicals is assumed to be the only means of termination, as combination is thought to be overwhelmingly dominant as the mode of termination in alkyl acrylates. [11,12] To apply the macroscopic rate constants used in our previous paper [5] to the well-mixed KMC simulation, the rate constants must be scaled down to the level of reactions between individual molecules. Values for the molecular rate constants are listed in Table 2.…”

Kinetic Study of the Thermopolymerization of Furfuryl Methacrylate in Bulk by Mathematical Modeling. Part A: Simulation of Experimental Data and Sensitivity Analysis of Kinetic Parameters

“…copolymer composition, molecular weight averages) for both linear and branched polymers. [14][15][16][20][21][22][23][24][25][26][27] By applying this concept, a kinetic model of the cross-linking in the photopolymerization of FA and FM was developed. [2,3] This model was based on application of the method of moments to the formation of the primary chains in the cross-linked polymeric network according to the reaction mechanism which is composed of the five basic steps shown in Figure 1.…”

“…Kinetics parameters responsible for this effect are g and k tc which belong to the cross-termination step. Sensitivity coefficients related to these parameters, S g and S k tc , were calculated at temperature 353 K and at different polymerization times using Equation (16). The results obtained are shown in Figure 3 where it can be observed that at the beginning of the polymerization ð0 < t < 120 sÞ, g is nonsensitive ðS g < 0:01Þ, whilst k tc (the cross-termination constant) is one of the dominating parameters in the proposed mechanism ðS k tc ) 0:01Þ.…”

“…Such modifications were introduced in this work. On the other hand, the possibility of substantial changes occurring in the kinetic mechanism and in the characteristics of the threedimensional network as a result of thermal initiation, and the possible presence of a gel effect which may take place at high monomer conversion, [14][15][16][17] should not be excluded. The reliability of the kinetic scheme was assessed by sensitivity analysis in order to evaluate the effect of the variation of each rate constant on the results of modeling, and also to estimate not only the contribution of each simple step in the proposed mechanism but also the variation of this contribution with temperature and reaction time.…”