Thermal analysis oxidation indices

As part of a multi-technique investigation (see also discussion under mid-infrared spectroscopy later), Corrales et al. [13] plotted the carbonyl index for films prepared from three grades of polyethylenes a high-density PE (HDPE), a linear low-density PE (LLDPE) and a metallocene PE (mPE) (see Figure 5). In this study, the data trend shown in Figure 5 correlated well with activation energies derived from the thermal analysis, which showed that the thermal-oxidative stability followed the order LLDPE > mPE > HDPE, whereas the trend... 

Outdoor exposure of these hlgh-denslty samples for the last 18 years caused no substantial change due to surface oxidation. Bulk changes similar to those found In low-density polyethylene were also found In these high density materials. The melt Index slowly decreases and the overall thermal stability measured at high temperature by thermal analysis decreases. However, the secondary crystallization seen In low-density polyethylene was not detected In these high density compounds. 

Single sheet glass Thermogravimetry Temperature index Thermal mechanical analysis Total oxidized layer... 

The effect is examined of tetramethyl thiuram disulphide (TMTD) on the heat ageing and oxidation of clay-filled NR, with reference to the plasticity retention index of NR, using thermal analysis and scanning electron microscopy test methods. The results showed that heat and oxygen resistant properties could be obtained when the clay-filled natural rubber compound was cured by semi-effective or effective curing systems, with 1.5 phr or 3.0 phr of TMTD. 3 refs. 

Figure 25.9 The relative contributions of the thermal Ep (1), prompt Ep (2), and nitrous oxide Fat (3) mechanisms as well as reburn Er (4) to the emission index and the net emission index found from Eq. (25.2) (symbols 5 — Eno ) predicted by RRA analysis for methane-air diffusion flames at p = 1 bar and oxidizer and fuel stream temperatures of Tf = To = 300 K...

Among the most common methods to measure thermal and oxidative behavior of oils are the classical oxidative stability analysis used by industries, based on the active oxygen method (AOM), which determines the number of hours required for the oil to reach a peroxide value of 100 meq/kg O and the oxidative stability index (OSI), which can be considered as automated AOM with an apparatus that simulates the events under specific atmospheres, usually with the use of high temperatures. The OSI method measures the changes in water conductivity when the oxidation compounds are formed [17]. 

Double films formed on InP were studied by applying ex situ ellipsometry after successive etching steps of the thermally formed oxide by an HF solution. From calculations based on a four-phase model (see Appendix A1 for treatment of two and more layers), the existence of an easily etched outer layer with smaller refractive index and a more durable inner layer with larger index was shown, which is consistent with XPS analysis. In the same work, in situ ellipsometry data was shown to be explained by the presence of a liquid layer when a microscopic model based on the Lorentz-Lorenz relation was used. Other ellipsometric studies of double films, such as double films of Si02 and Si3N4 on Si, have been reported. 

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