Determination of reactivity ratios from analysis of triad fractions—analysis of the copolymerization of styrene and acrylonitrile as evidence for the penultimate model

Modern aspects of quantitative theory of free-radical copolymerization

“…16, the best agreement between the experimental data and theory is observed when the penultimate model is applied. Further investigations performed by Australian scientists [283][284][285] also support this conclusion. Following the general strategy outlined in Sect.…”

“…This was an additional argument [283] in favor of the reliability of the penultimate model for the description of the bulk copolymerization of styrene and acrylonitrile. The parameters of this model determined independently both via the analyses of the copolymer composition and sequence distribution were found to be rather close to each other [283][284][285]. This fact also proves the validity of the penultimate model.…”

Discriminating between the Terminal and Penultimate Models Using Designed Experiments: An Overview

“…For example, parts a and b of Figure 5 show the results of run 14 (conditions given in Table 10) in which the modified Buzzi-Ferraris and Forzatti method was applied to the system STY/AN. The conditions used to simulate the data in parts a and b of Figure 5 closely duplicate the experimental conditions used by Hill et al (1989) in parts a and b of Figure 6. The data in parts a and b of Figure 5 were simulated using the strong penultimate model as the "true" model with reactivity ratios r 11 ) 0.230, r 21 ) 0.634, r 22 ) 0.039, and r 12 ) 0.091 (s 1 ) s 2 ) 0.700).…”

“…Triad fraction data ofHill et al (1989) for STY/AN. The simulation predictions were calculated using the penultimate reactivity ratios r11 ) 0.230, r21 ) 0.634, r22 ) 0.039, and r12 ) 0.091.…”

Modeling of the Penultimate Unit Effect in Chain-Growth Copolymerizations

“…Typically, polymerization systems comprising styrene/acrylonitrile [15][16][17][18][19][20], methyl methacrylate/n-butyl acrylate [21], ethylene/styrene [22], dimethyl itaconate/styrene [23], ethylene/4-methyl-1-pentene [24], α-alkylstyrenes/acrylonitrile [25], styrene/methyl methacrylate [26], p-chlorostyrene/methyl acrylate [27], styrene/isobutylene [28], methyl α-(trifluoromethyl)acrylate and α-(trifluoromethyl) acrylonitrile with styrene, p-chlorostyrene and methyl methacrylate [29], styrene/maleic anhydride [30], isobutyl methacrylate/lauryl methacrylate [31], and styrene/fumaronitrile [32,33] demonstrate a strong penultimate unit effect, representing good examples of the successful implementation of the penultimate model [9,34].…”