Thermal behaviour

Erdelen C, Laschewsky A, Ringsdorf H, Schneider J and Schuster A 1989 Thermal-behaviour of polymeric Langmuir-Blodgett multilayers Thin Solid Films S0 153-66... 

R. Antony, Synthesis, Characterization and Thermal Behaviour of Chemically Modified Phenolic and Substituted Phenolic Polymers, Ph.D thesis. Regional Research Laboratory, Trivandrum and Kerala University, Trivandrum, India (1993). 

Reaction Mechanism of Li, vNi()2 and Its Thermal Behaviour with Organic Electrolyte... 

Decomposition of NH4V03 proceeds to completion in several successive stages, some of which are reversible, so that thermal behaviour is sensitive... 

The epoxy matrix was filled with iron particles of average diameter df = 150 pm at a volume fraction uf = 0.05. The mechanical and thermal behaviour of the particulate composite was studied in Ref. 8), which gave the following values ... 

Aromatic and aliphatic bromine compounds play an important role as industrial products, e.g. special products are widely used as flame retardants for polymeric materials (ref. 1). Because there is an increasing interest and concern about the behaviour and fate of anthropogenic compounds in the environment (ref. 2), we have studied the physical behaviour and chemical reactivity of these products which are relevant to the environment. The main object is the study of their thermal behaviour during incineration, as well as photolytic reactions. Of prime concern is... 

Study of the Thermal Behaviour of Bromine Containing Flame Retardants during Incineration... 

First, thermal behaviour of decabromobiphenyl ether 1 will be described. The thermal reactivity of this compound depends on the applied conditions the pure compound reacts completely different in comparison to its reaction in polymeric matrices. Thermolysis of the pure compound gives a good yield (60 %) of hexabromobenzene. The main products obtained by incineration in th DIN oven at three temperatures for pure 1 and of 1 within a polypropylene matrix are shown in Table 1. 

Zanetti, M., Camino, G., Thomann, R. and Mulhaupt, R. 2001. Synthesis and thermal behaviour of layered silicate-EVA nanocomposites. Polymer 42 4501- 4507. 

The thermal stability of the polymers is remarkably dependent on their molecular weight that is, the higher the molecular weight, the lower is their thermal stability. Such peculiar thermal behaviour has been interpreted as a... 

Influence of the metal ions on the thermal behaviour of the gels... 

Table 2. Thermal behaviour of the gels. Temperatures [°C], where minimal storage moduli were observed on reheating. Concentrations of ions in mmol / lOOg gel, [V " ] = added bivalent ion, [Z ] = added monovalent ion, [C1 ] = 2.5, 2[V+ ]+[Z+]=2.5 or [Na ]+[K ]=2.5.

Nicholson, J. W., Wasson, E. A. Wilson, A. D. (1988). Thermal behaviour of films of partially neutralised poly(acrylic acid). 3. Effect of calcium and magnesium ions. British Polymer Journal, 20, 97-101. 

A violent decomposition took place when the final compound was decanted. The technical analysis showed that the chlorosulphonic derivative obtained decomposes at a temperature starting at 24-27 C. Oomparing the thermal behaviours of the four compounds just described could be interesting in terms of finding out more about stability factors of a molecule and is a good test to check the CHETAH method (see para 2.3). 

The use of copolymers is essentially a new concept free from low-MW additives. However, a random copolymer, which includes additive functions in the chain, usually results in a relatively costly solution yet industrial examples have been reported (Borealis, Union Carbide). Locking a flame-retardant function into the polymer backbone prevents migration. Organophosphorous functionalities have been incorporated in polyamide backbones to modify thermal behaviour [56]. The materials have potential for use as fire-retardant materials and as high-MW fire-retardant additives for commercially available polymers. The current drive for incorporation of FR functionality within a given polymer, either by blending or copolymerisation, reduces the risk of evolution of toxic species within the smoke of burning materials [57]. Also, a UVA moiety has been introduced in the polymer backbone as one of the co-monomers (e.g. 2,4-dihydroxybenzophenone-formaldehyde resin, DHBF). 

Halogen bonding is also observed with electron-poor bromides, and so attempts were made to form complexes between stilbazole and fcromopenta-fluorobenzene. We were never able to find evidence that such a complex formed and indeed, heating crystallised samples only reproduced the thermal behaviour of the stilbazoles themselves. Thus, any halogen bonding is supposed weak (there was no observable colour change in the stilbazole) and unable to sustain the complex at temperatures much above ambient. 

Examination of the thermal behaviour showed that with three exceptions, all complexes showed a monotropic SmA phase with in almost all cases, melting being observed between 88 and 99 °C, with clearing between 82 and 89 °C. Of the three exceptions, 15-6,8 and 15-8,10 showed no liquid crystal phase at all, while 15-12,6 showed an additional monotropic nematic phase. A curious feature of these complexes is the apparent insensitivity of the melting and clearing points to both n and m. 

Relatively little systematic work has been carried out on the thermal behaviour of the bicyclic peroxides compared to monocyclic systems 63). From the few results obtained to date, oxygen diradicals appear to be reasonable intermediates to account for the observed products (Eq. 51). 

To the best of our knowledge, no direct connection exists between this thermal behaviour of the model bicyclo[2.2.1] system 9 and prostaglandin endoperoxide 4,... 

Thus, whereas the thermal behaviour of the parent system 9 is akin to that of... 

Pyrolysis-MS, together with TGA analysis, was chosen recently as the technique with which to investigate the thermal behaviour of two polythiophene copolymers, since insolubility in common solvents of conducting polymers limits... 

The salts can be classified in three main classes salts which undergo thermal dissociation to acid and melamine salts of strong acids which catalyse melamine condensation salts of acids which react with melamine condensation products. Implications of the thermal behaviour of the salts in the mechanism of fire retardance is briefly discussed. 

Melamine and its salts are widely used in formulations of fire retardant additives, particularly of the intumescent type (4-71. The role played by melamine structures in these additives is however not yet understood. The thermal behaviour is of paramount importance in studies of the fire retardance mechanism. It is known that melamine undergoes progressive condensation on heating with elimination of ammonia and formation of polymeric products named "melam", "melem", "melon" (8.91. The following schematic reaction is reported in the literature (10-121 ... 

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 ... 

The TG and DTG curves of Figure 12 show that melamine polyphosphate undergoes a complex degradation process between 330-650 C. In step 3 of the DTG curve (max. rate 390 C), water, ammonia and melamine are evolved. In this step the thermal behaviour of polyphosphate is somewhat similar to that of the sulphate in the same range of temperature (300-400 0. Indeed evolution of melamine indicates that thermal dissociation of polyphosphate giving free melamine takes place above 330 C. However, evaporation of melamine competes with its condensation as shown by evolution of ammonia. 

Figure 12). In this step the DTG curve shows a very broad peak with a narrower maximum superimposed (550 C) indicating the occurrence of different overlapping processes. This thermal behaviour cannot be explained on the basis of that of melamine condensation products or of ultraphosphates (e.g. ammonium salt). Indeed melamine condensate undergoes complete fragmentation to volatile products below 750 C (18) while ammonium ultraphosphate does so mostly below 700 C (29). in TG at 10 C/min. The presence of P in the material obtained at 650 C is shown by the solid state 31P NMR which however gives broad complex... 

---