Temperature and degradation

Some sources consider aspartame a nutritive sweetener. It is sensitive to low pH and high temperatures and degrades over time. Aspartame can be used alone or in a blend with other sweeteners. 

Finally, the effect of temperature on the life of anion exchange resins must be considered. Many of these materials are sensitive to high temperatures, and degradation of the resin may result if process tem-... 

Conversation with the dye manufacturer revealed a mistake had been made in recommendation of the disperse dye to be used in conjunction with the high-energy reactive dye. The recommended dye was an azo-based dye that was not stable to base at high temperatures, and degradation caused the purplish shade shift observed in the research. For future investigations, an anthraquinone-based disperse dye that is base-stable at 170°C has been recommended by the manufacturer for use with the high-energy reactive dye. 

The hot char [300 to 1000 C as measured by infrared pyrometry (44)] and ash provide surfaces which can catalyze secondary thermal reactions of the reactive fragments of the escaping volatiles. The char can also be consumed by them as suggested by Lewellyn et al. However, both processes occur at temperatures lower than the effective plasma temperature and degradation is not as severe. 

Polypropylene is not very stable at the melt temperature and degrades at room temperature, particularly in the presence of UV light. It is not dyeable coloration requires the addition of... 

Figure 1. Rate of the hydrolysis of different aliphatic polyesters with a lipase from Pseudomonas sp. at different degradation temperatures. Left side correlation with the melting point of the polyesters right side correlation with the difference between melting temperature and degradation temperature...

Table 6.4 Weight loss at different temperatures and degradation temperature peak of polypropylene and fibers/PP composites.

Use of tip nozzles is not recommended for shear-sensitive plastics (which include plastics with flame retardants or organic dyes), since the small annular gap in the gate may cause large shear stresses to arise, with a rise in temperature and degradation of the plastic or the additives in it. 

High shear zones are present between the flanks (sides) of the flights, this possibly giving rise to problems related to excessive temperature and degradation. 

Thermal stability of polymers or polymer composites determines the upper-limit of the working temperature and the environmental conditions for use, which are related to their thermal degradation temperature and degradation rate [132, 133]. The TGA thermograms of... 

The increase in the thermal degradation temperatures of the PEN/CNT nanocomposites with the incorporation of the CNT m be explained by the decrease in the evolution rate of volatile degradation products in the polymer nanocomposites. The thermal degradation temperatures and degradation kinetic parameter are in common use to estimate the thermal... 

The rigid rodlike structure of poly-p-phenylene terephthalamide results in a very high crystalline melting temperature and degradation rather than melting, which makes melt processing impossible. Instead, this polymer is spun from liquid crystalline polymer solutions (see Section 3.5). 

Similar models were constructed for glass-fibre reinforced polyester composites, which were degraded for 20 years at 40°C and 60 C. By PCA it was not possible to find a pattern relating the degradation products identified by head-space-GC-MS with temperature and degradation time. By partial least square (PLS) it was instead revealed that two different degradation mechanisms were operating at the two temperatures [35]. 

A comparison of the physical properties of hyperbranched and dendritic macromolecules with linear polymers and the linear analogs of these 3-dimensional polymers is presented. It is found that thermal properties, such as glass transition temperature and degradation, are the same regardless of the macromolecular architecture but are very sensitive to the number and nature of chain end functional groups. However, other properties, such as solubility, melt viscosity, chemicd reactivity, intrinsic viscosity were found to be very dependent on the macromolecular architecture. 

What are heat capacity, specific heat, thermal conductivity, coefficient of thermal expansion, glass transition temperature, melting temperature, and degradation and decomposition ... 

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