Modeling of polymerization of melamine and formaldehyde using a functional group approach

Kumar, Anil; Chandra, Ram

doi:10.1002/pen.760271302

Cited by 5 publications

(3 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is expected that ks is a function of temperature as well as the F/M ratio. Equations 6a and 7a can now be modified to A + F, ^B + CH2OH + H20 A + CH20H^B + Z + H20 (7a) where fell = fe8fei (13) and the mole balance equations for model I as given in Table II for formaldehyde, melamine, and species B modify to…”

Section: Resultsmentioning

confidence: 99%

Modeling and experimental investigation of melamine-formaldehyde polymerization

Kumar¹,

Katiyar²

1990

Macromolecules

View full text Add to dashboard Cite

Polymerization of melamine with formaldehyde has been studied at high temperatures and molar ratios of monomers similar to those used in industry. Melamine dissolves in formaldehyde slowly and ionizes in the reaction mass to some extent. The polymer formation is a complex process of polymerization of the un-ionized molecules of melamine. Using the functional group approach, we have modeled the batch polymerization and determined the rate constants through curve-fitting. We find that the rate constants are a function of temperature only, and the kinetic model proposed in our work describes the polymerization in the entire region.

show abstract

Section: Resultsmentioning

confidence: 99%

Modeling and experimental investigation of melamine-formaldehyde polymerization

Kumar¹,

Katiyar²

1990

Macromolecules

View full text Add to dashboard Cite

show abstract

“…Consider the detailed kinetics of Table IV. Equations (9)(10)(11)(12)(13)(14) are equivalent to eqs. (1)(2)(3)(4)(5)(6), except for the fact that any M-based molecule is characterized by P A 0 ;A 1 ;A 2 ;M 0 ;E 0 ; where A 0 , A 1 , and A 2 are the number of primary, secondary, and tertiary amines [ANH 2 , ANHCH 2 OH, and AN(CH 2 OH) 2 , respectively]; and M 0 and E 0 are the number of unsubstituted methylene and ether bridges (ANHCH 2 NHA and ANHCH 2 OCH 2 NHA, respectively).…”

Section: Mathematical Modelmentioning

confidence: 99%

“…The model produces a gross estimate of the average number of rings per molecule 11. Kumar and Chandra12 extended the model by Gupta,11 by assuming either irreversible methylolations with reversible condensations or reversible methylolations with irreversible condensations; and adjusted the five associated kinetic constants on the basis of the mentioned measurements by Tomita 8. Kumar and Katiyar13 readjusted the models by Kumar and Chandra12 on the basis of new measurements from a single variable, the total formaldehyde concentration.…”

Section: Introductionmentioning

confidence: 99%

Methylolation of melamine with incipient condensation. II. Mathematical modeling

Nicolau

Estenoz

Meira

2009

J of Applied Polymer Sci

View full text Add to dashboard Cite

A novel mathematical model is presented for the reaction between melamine (M) and formaldehyde (F) at pH ¼ 9.0 and at temperatures between 38 and 90 C. It is based on a kinetic scheme that includes reversible methylolations, irreversible formation of (unsubstituted) methylene bridges, reversible formation of (unsubstituted) ether bridges, instantaneous dissolution of M, and instantaneous equilibrium for the hydration/dehydration of F. The model predicts the distributions of molecular weights and functionalities of the evolving MF resin. Arrhenius expressions were adjusted for the seven kinetic constants on the basis of measurements reported in the first part of this series. Even though the final products contain thousands of different molecular species, 21 of them constitute more than 90% of the total weights. During the initial period with negligible condensation, the undissolved M distorts the distributions of molecular weights and functionalities; but the reversibility of methylolations corrects for such distortion prior to the effective start of condensation.

show abstract

Homogeneous methylolation of melamine: Mathematical modeling

Nicolau

Estenoz

Meira

2007

J of Applied Polymer Sci

View full text Add to dashboard Cite

A novel mathematical model is presented on the methylolation of melamine with formaldehyde at 488C and pH 9.0. The model assumes an instantaneous hydration/dehydration of formaldehyde and the methylolation mechanism of Gordon et al. (J Appl Polym Sci 1966, 10, 1153. The 24 kinetic constants were adjusted to experimental measurements by Tomita (J Polym Sci 1977, 15, 2347. The model predicts the evolutions of the comonomers and the nine methylolated species. This is the first article of a series that aims at developing a detailed model for the industrial synthesis of melamine-formaldehyde resins.

show abstract

Modeling of polymerization of melamine and formaldehyde using a functional group approach

Cited by 5 publications

References 9 publications

Modeling and experimental investigation of melamine-formaldehyde polymerization

Modeling and experimental investigation of melamine-formaldehyde polymerization

Methylolation of melamine with incipient condensation. II. Mathematical modeling

Homogeneous methylolation of melamine: Mathematical modeling

Contact Info

Product

Resources

About