Melamine derivatives

A completely different situation may arise when melamine derivatives, e.g. melamine salts are introduced in the polymeric material, owing to the thermal behaviour of the salts which depends on the type of acid combined with melamine. We have characterised the thermal behaviour of a wide number of melamine salts and found that they may be classified into three main classes ... 

Reactive prepolymers used as binders are produced by acrylation of oligomers, such as epoxy resins, urethanes, polyesters, silicones, oligo-buta-diene, melamine derivatives, cellulose, and starches. Prepolymers are the principal ingredients of coating formulations and largely determine the basic properties of the coating. Examples of industrially important acrylated prepolymers are in Table 5.9. 

Biguanides react with carbodiimides to form melamine derivatives in 60-70% yields (equation 50) (64JCS3459), and with isothiocyanates to form the 1,3,5-triazinethione (98 equation 51) (65JCS6296). 

Dyes can also be incorporated into hydrogen-bonded superstructures using the complementarity of the hydrogen bond donors and acceptors. The addition of a perylene bisimide dye to chiral dialkyl melamine derivatives leads to aggregates (Fig. 26) which show induced circular dichroism in the dye part of the assembly in methylcyclohexane as well as the formation of mesoscopic fibres when the solvent is evaporated [227]. The melamine compounds... 

Fig. 26 The assembly of a perylene imide dye with a chiral melamine derivative to give chiral supramolecular chains...

Melamine Pure melamine, melamine derivatives (salts and inorganic acids), melamine homologues Polyurethane, polyamide, polyolefins, thermoplastic polyesters Akzo Nobel, Budenheim, Ciba Specialty Chemicals-Melapur... 

Reinhoudt et al. have chosen tetraether derivatives of calix[4]arenes fixed in the cone-conformation as such a molecular skeleton.280 Bis-melamine derivatives 135 are easily prepared in a huge diversity (different residues Y, R1, R2) from 1,3-diamino calix[4]arenes by reaction with cyanurchloride, followed by stepwise substitution of the remaining chlorine atoms by ammonia and an aliphatic amine. 

Figure 37. Chiral bis-melamine derivatives and chiral cyanurates used in self-assembly studies.

Alkylated triazines of the current have also been prepared by heating melamine or melamine derivative and an alcohol in the presence of a hydrogenation-dehydrogenation mixed catalyst such as 5% palladium on carbon (50% hydrated) with 25 mg of Cu0/Cr203/Ni0/Ba0 and is reviewed (4). 

N. Kimizuka, S. Fujikawa, H. Kuwahara, T. Kimitake, A. Marsh, J.M. Lehn, Mesoscopic Supramolecular Assembly of a Janus Molecule and a Melamine Derivative via Complementary Hydrogen-Bonds , J. Chem. Soc., Chem. Commun., 2103 (1995)... 

FIXAPRET BU occupies a special position within the range of reactant-type products. It reacts mainly with the hydroxyl groups of the cellulose, but it also forms crosslinkages with Itself. Uike the melamine derivatives, it occupies an intermediate position between the reactant types and the selfcrosslinking agents. 

A thermosetting melamine derivative in water that cross links polymeric materials builds hand of nylon fabric and provides shrinkage control to cellulosic fabrics. 

Type Melamine derivative Appearance Clear viscous liquid... 

The synthesis of alkoxysilyl-modifted melamine derivatives comprised the formation of the triamino substituted triazine ring from trichloro triazine and simultaneous introduction of a hydrolysable organoalkoxysilyl group. Thus, aminopropyltriethoxysilane or A -methylaminopropyltrimethoxysilane reacts with 2,4,6-trichloro-l,3,5-triazine or with partially A, A -diethylamine-substituted triazine to give the triazine derivatives 7 to 12 (Eq. 4. Table 2). 

A melamine derivative containing a guanidinium functionality has been constructed by Yano and coworkers which has exhibited very tight binding (ATa of 1.4 X 10 M in chloroform) to 6-azaflavin [47], The proposed structure of the complex has five hydrogen bonds between the host and the guest (Figure 34). 

ANTIMICROBIAL POLYMERS CONTAINING MELAMINE DERIVATIVES. I. PREPARATION AND CHARACTERIZATION OF CHLOROMELAMEVE-BASED CELLULOSE... 

By the propoxylation of the synthesised melamine derived Mannich base, without catalyst, a hexafunctional polyether polyol is obtained (reaction 15.40). 

Potassium 1,2-dicyanoguanidide (15) reacts with aliphatic and aromatic amines to provide melamine derivatives 18. Aromatic amines require strongly acidic conditions (pH < 1),458 otherwise isomelamines are formed.462 Aliphatic, cycloaliphatic and aromatic secondary amines afford the corresponding A-substituted melamines.459,460... 

---