1.2.4- Triazines thermal stability

It does have a number of draw backs. It has poor thermal stability (a property common to most formaldehyde release biocides) and, in some instances, may cause blackening of metalworking fluid concentrates if heated above 50°C for a period of time. Recently, this active ingredient was placed on Annex 1 of the Dangerous Substances Directive having been identified as a potential skin sensitiser. This means that formulations containing efficacious levels of this class of triazine in them would have to be labelled with R43 - may cause sensitisation by skin contact. This is unacceptable to many UK customers. As this material is only bactericidal, it needs to be co-formulated with a fungicide to provide complete protection for a product. 

This material shares many of the advantages of the triazine biocides. They are relatively cheap, compatible with most formulations and provide a source of reserve alkalinity. In addition, at the time of writing, there are no requirements for labelling R43 with this class of material. It shares similar disadvantages to the triazines, possessing poor thermal stability. Oxizolidines also need to be co-formulated with a fungicide to provide complete protection for a product. 

Triazines are well-known compounds with high thermal stability and higher EA than 1,3,4-oxadiazoles (PBD) and 1,2,4-triazoles (TAZ, 92). Schmidt et al. studied a series of dimeric 1,3,5-triazine ethers for application as ETMs for OLEDs [150], However, despite their high EA, the efficiency of the OLEDs improved only modestly. One possible explanation is due to their rather poor electron mobilities. 

On the basis of an IR study of some s-triazines and HA systems, several authors reported that ionic bonding took place between a protonated secondary amino group of the s-triazine and a carboxylate anion on the HA [17,146,147]. Successive studies, mainly conducted by IR spectroscopy, confirmed previous results and also provided evidence for the possible involvement of the acidic phenol-OH of HA in the proton exchange of the s-triazine molecule [17, 146-150]. Differential thermal analysis (DTA) curves measured by Senesi and Testini [146, 147] showed an increased thermal stability of the HA-s-triazine complexes, thus confirming that ionic binding took place between the interacting products. 

Coburn " synthesized 2,4,6-tris(picrylamino)-l,3,5-triazine (TPM) (190) from the reaction of aniline with cyanuric chloride followed by nitration of the product with mixed acid. Treatment of TPM (190) with acetic anhydride-nitric acid leads to Al-nitration and the isolation of the corresponding tris-nitramine. The high thermal stability of TPM (m.p. 316 °C) coupled with its facile synthesis and low sensitivity to impact has led to its large scale manufacture in the US by Hercules Inc. China has reported a low-cost synthetic route to TPM but this has a limited production capacity. 

Azapteridines (pyrimido[4,5- ]-l,2,4-triazines) are stable solids with good thermal stability. Thus, the 3,6-diaryl-pyrimido[5,4- ]-l,2,4-triazines 18 (R = Ar) show melting points in excess of 350°C without decomposition after recrystallization from ethanol. The corresponding 6-unsubstituted system 18 (R = H) shows decomposition at 325°C <2003CCC965>. These systems are soluble in chloroform. 

The imidazo-fused pyridazino[6,5- ]-l,2,4-triazines 23 are stable to silica gel chromatography and also show high thermal stability, giving melting points in excess of 250°C upon recrystallization from dimethylformamide (DMF) <1999CHE376, 1999KGS426>. 

The crosslinked triazine (or cyanurate) polymers distinguish themselves by high glass temperatures and improved thermal stability. 

The authors claim that the thermal stability of polymers with aroxy-triazine groupments is much better than that with alkoxy-triazine fragments. It can be assumed that the proper way to increase the thermal stability is to enhance oxazoline ring formation. 

Modification of poly(carbodiimide) foams with polyols afford hybride foams containing urethane sections. However, the thermal stabilities of the poly (urethane carbodiimide) foams are lower. Using isocyanate trimerization catalysts, such as l,3,5-tris(3-dimethylaminopropyl)hexahydro-s-triazine, in combination with the phospholene oxide catalyst gives poly(isocyanurate carbodiimide) foams with improved high temperature properties. The cellular poly(carbodiimide) foams derived from PMDI incorporate six-membered ring structures in their network polymer structure. ... 

Thermal Stability of Triamino Triazine and Phosphazene Modified Polysiloxanes... 

A significant research effort has been directed toward fluorinated triazine polymers,208,218-221 and examples of the formation of these interesting elastomers of very high thermal stability are given (Eqs. 67218 and 68219). 

The thermal stabilities of the parent systems vary from 1,2,3-triazine, which decomposes at about 200 °C, to 1,3,5-triazine, which is stable to over 600 °C - at this temperature it decomposes to give hydrogen cyanide, of which it is formally a trimer. Melamine (2,4,6-triamino-l,3,5-triazine) is an important industrial intermediate (34.6.2). Its high nitrogen content has led to its illegal misuse in foodstuffs to achieve higher nitrogen analyses. 

The polyimide class of polymers are known to possess a high degree of thermal stability. They decompose in an inert atmosphere around 500°C and in air about 400°C as indicated by thermo-gravimetric analysis (1). Because of the great thermal stability of 2,4,6-triphenyltriazine (2J (decomposes above 486°C), copolymerization of this compound with imides should lead to enhanced heat resistant materials in the form of triaryl-s-triazine ring (TSTR) cross-linked (XL) polyimides. 

Triazine-2,4,6-triamine. N,N, N",N" -Tetrakis(4,6-bis(butyl-(N-methyl-2,2,6,6-tetramethylpiperidin-4-yl)-amino)triazin-2-yl)-4,7-diazadecane-1,10-diamine. Light and thermal stabilizer for PP fiber applications in automotive, marine and residential carpets, agricultural films, fertilizer bags, thick section pigmented applications, rotational molding applications. Ciba-Geigy Corp. 

Korshak and Rusanov [232] reviewed in detail the studies conducted on phenyl substituted poly-heteroarylencs. Phenyl substituted polyquinazolinones [233-236] were reported to be thermally stable up to 420°C in air and polyimidincs also showed a high thermal stability as evident from 10% weight loss in the temperature range of 400 -525°C and 450°-560°C in air and in an inert environment, whereas comparatively low thermal stability was observed in polypyrrolinones. Unsubstituted poly(l,2,4-triazine)s and polyphenyIqui-... 

Diels-Alder cycloaddition of 4,6-dimethyl-1,2,3-triazine (317) with enamines 318 was performed under MWI at 140 150 °C in a focused MW reactor to give the corresponding heterocyclic products 319 within 20 min and in 32-71% yields (Scheme 65) the conventional method needed 1-2 h. The relatively modest yields were explained by the poor thermal stability of the 1,2,3-triazines and enamines (01SL236). 

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