New results in hydrolytic lactam polymerization

Bertalan, György; Rusznák, István; Anna, P.

doi:10.1002/macp.1984.021850702

Cited by 7 publications

(13 citation statements)

References 18 publications

(1 reference statement)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These additional reactions are summarized in Table 4 and they can influence the equilibrium concentrations of end groups and may be useful for obtaining an improved understanding of apparent polycondensation equilibria. For example, terminal cyclic amidine ends have been observed during the polymerization of caprolactam at low water concentrations and relatively high temperatures (≥254 °C) . Bertalan et al.…”

Section: Reaction Mechanism and Literature Reviewmentioning

confidence: 99%

Modeling Equilibrium Behavior of Nylon 6, Nylon 6,6 and Nylon 6/6,6 Copolymer

Liu

Marchildon

McAuley

2019

Macro Reaction Engineering

View full text Add to dashboard Cite

Nylon 6 and nylon 6,6 reaction equilibria depend in a complex way on water concentration and temperature. For example, data sets from six research groups reveal that the apparent equilibrium constant for polycondensation increases with water at low water concentrations, reaches a maximum, and then decreases as the water concentration rises further. In this article, semi‐empirical expressions are proposed to describe the experimentally observed equilibrium behavior for the five main reactions that occur during nylon 6 and nylon 6,6 polymerization. Nine side reactions involving amidine ends, cyclopentanone ends, and hydrated carboxyl ends are used to develop expressions that account for the influence of both water and temperature on these equilibrium constants. Excellent fit to the data, over the entire range of the available nylon 6 and nylon 6,6 literature data, suggests that the proposed equations will be helpful for modeling reaction equilibria for nylon 6/6,6 copolymerization.

show abstract

Section: Reaction Mechanism and Literature Reviewmentioning

confidence: 99%

Modeling Equilibrium Behavior of Nylon 6, Nylon 6,6 and Nylon 6/6,6 Copolymer

Liu

Marchildon

McAuley

2019

Macro Reaction Engineering

View full text Add to dashboard Cite

show abstract

“…As shown in Table 5, amidine ends can react with carboxyl ends (reaction R7) to produce amide links and can also be hydrated to form regular amine ends (reaction R8) 56–59. To our knowledge, no literature information is available about the reaction kinetics involving amidine ends.…”

Section: Model Extension and Parameter Estimationmentioning

confidence: 99%

Improved Kinetic Rate Constants for Nylon 6, Nylon 6,6, and Nylon 6/6,6 Copolymer

Liu

McAuley

2019

Macro Reaction Engineering

View full text Add to dashboard Cite

Nylon 6 and 6,6 literature data are collected over a wide range of water concentrations and temperatures (0 ≤ [W]0 ≤ 40.8 wt%, 200 ≤ T ≤300 °C) and used to fit parameters in an updated batch reactor model. The resulting copolymerization model uses side reactions to account for the complex influence of water on kinetics and reaction equilibria. The proposed parameter estimates result in a significant improvement in the fit to the data, corresponding to a 73% reduction in the weighted‐least‐squares objective function compared to when the parameters of Arai et al. are used. Copolymerization simulations are conducted at industrially relevant conditions, shedding light on the complex influence of water and on the potential to include waste nylon 6 cyclic dimer in the feedstock. The model and parameter estimates will be helpful in future models of nylon 6/6,6 copolymerization in continuous reactor systems.

show abstract

“…The highest molecular weights obtained in these polymerizations are 10,000-20,000. The most significant side reaction is amidine (XXXI) formation [Bertalan et al, 1984]. Propagation of the polymer chain and amidine formation proceed through the common intermediate XXX formed by attachment of an amine group to the protonated carbonyl of any amide group (that in lactam monomer or the lactam end group in polymer or the amide groups in the repeat units of the polymer).…”

Section: -3a Cationic Polymerizationmentioning

confidence: 99%

“…2-8f) is carried out commercially in both batch and continuous processes by heating the monomer in the presence of 5-10% water to temperatures of 250-270 C for periods of 12 h to more than 24 h [Anton and Baird, 2002;Zimmerman, 1988]. Several equilibria are involved in the polymerization [Bertalan et al, 1984;Sekiguchi, 1984]. These are hydrolysis of the lactam to E-aminocaproic acid (Eq.…”

Section: -3b Hydrolytic Polymerizationmentioning

confidence: 99%

See 1 more Smart Citation

Ring‐Opening Polymerization

Odian

2004

Principles of Polymerization

View full text Add to dashboard Cite

A wide variety of cyclic monomers have been successfully polymerized by the ring-opening process [Frisch and Reegan, 1969; Ivin and Saegusa, 1984;Saegusa and Goethals, 1977]. This includes cyclic amines, sulfides, olefins, cyclotriphosphazenes, and N-carboxy-a-amino acid anhydrides, in addition to those classes of monomers mentioned above. The ease of polymerization of a cyclic monomer depends on both thermodynamic and kinetic factors as previously discussed in Sec. 2-5.The single most important factor that determines whether a cyclic monomer can be converted to linear polymer is the thermodynamic factor, that is, the relative stabilities of the cyclic monomer and linear polymer structure [Allcock, 1970;Sawada, 1976]. Table 7-1 shows the semiempirical enthalpy, entropy, and free-energy changes for the conversion of cycloalkanes to the corresponding linear polymer (polymethylene in all cases) [Dainton and Ivin, 1958;Finke et al. 1956]. The lc (denoting liquid-crystalline) subscripts of ÁH, ÁS, and ÁG indicate that the values are those for the polymerization of liquid monomer to crystalline polymer.Polymerization is favored thermodynamically for all except the 6-membered ring. Ringopening polymerization of 6-membered rings is generally not observed. The order of thermodynamic feasibility is 3,4 > 8 > 5,7 which follows from the previous discussion (Sec. 2-5c) on bond angle strain in 3-and 4-membered rings, eclipsed conformational strain in the 5-membered ring, and transannular strain in 7-and 8-membered rings. One notes that RING-OPENING POLYMERIZATION RING-OPENING POLYMERIZATION

show abstract

New results in hydrolytic lactam polymerization

Cited by 7 publications

References 18 publications

Modeling Equilibrium Behavior of Nylon 6, Nylon 6,6 and Nylon 6/6,6 Copolymer

Modeling Equilibrium Behavior of Nylon 6, Nylon 6,6 and Nylon 6/6,6 Copolymer

Improved Kinetic Rate Constants for Nylon 6, Nylon 6,6, and Nylon 6/6,6 Copolymer

Ring‐Opening Polymerization

Contact Info

Product

Resources

About