Modeling and experimental investigation of melamine-formaldehyde polymerization

Abstract

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.

Engineering the mechanical and physical properties of organic–inorganic composite microcapsules

“…The detachment allowed us to measure the MF wall thickness as a function of reaction time. The wall thickness of the MF polymer increased from 129 ± 2.5 nm (batch 1, 4 h) to 160 ± 3.1 nm (batch 5, 24 h) when the MF cross-linking time increased from 4 to 24 h. Previous studies on the kinetics of the MF polymerization reaction showed that the polymerization mainly took place during the first 2-3 h of the reaction [18,19], which is in agreement with our result that the wall thickness does not increase much as the cross-linking time increased from 4 to 24 h. Prolonged reaction time produces more cross-linked network, and consequently results smaller pores on the wall [20].…”

Microencapsulation mechanism and size control of fragrance microcapsules with melamine resin shell

“…The weight loss ratio in this process is about 92.0 wt. % with the polymer structure was formed [31][32][33].…”

Homogeneous methylolation of melamine: Mathematical modeling

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] First, the hydroxymethylation (or ''methylolation'') is represented by 1,2 ÀÀH þ CH 2 O Ð À ÀCH 2 OH (1) where À ÀH is any reactive H of any amine group contained in M or its derived products. Then, a hydroxymethyl group can either react with another reactive H to produce a methylene bridge:…”