Irradiation melting temperature

Stabilizing Activity of Pyrocatechols in Thermal Oxidation and in y-Irradiation of Polypropylene. It is interesting to compare the relationships found on stabilizing isotactic polypropylene oxidized over the melting temperature with the results of our previous study (22, 23) of the stabilizing properties of some derivatives of pyrocatechol in y-irradiated polypropylene. 

The fuels for fast breeder reactors include alloys such as U-Pu-Zr and the ceramic materials UO2-PUO2, UC-PuC, and UN-PuN, but the mixed oxides, UO2-PUO2, are the choice for prototype fast breeder fuel elements because of their high melting temperature, compatibility with cladding and coolants, and relatively good irradiation stability and fission product retention. The disadvantages are the relatively low metal density, the... 

The photochemical cis-trans isomerization of the azochromo-phore can be achieved by irradiation at the maximum absorption band of the trans isomer at A=378 nm the change in the absorption spectra of a polymer film before and after irradiation is given in Fig. 8. Similar fractions of cis-isomers can be obtained in samples quenched from the melt (i.e.,ofrom above the melting temperature T of the soft phase T =45 C) and in samples annealed at temperature some degrees below of the soft phase, by which some soft segment crystallization was caused. 

Minkova [1987], and Minkova and Mihailov [1990] studied gamma-irradiation of blends of these two polymers, in air at RT, to doses up to 60 kGy. The blends of the two were prepared by passing their mixtures through a melt-flow indexer at 190°C, four times. The pure components were similarly treated. The melting temperatures for the first and... 

Crystallization enthalpies of the irradiated blends were lower than predicted by the additivity rule. The crosslinking of the amorphous domains lowered the melting enthalpies. Irradiated blends showed separated crystallizations, at their characteristic temperatures of crystallization, independent of composition. On irradiation, the crystallization temperature of PE did not change, whereas that of UHMWPE slightly decreased. Separate irradiation of UHMWPE and PE favored molecular scission over the crosslinking, whereas irradiation of the blends favored crosslinking. The melting temperature, T, increased linearly with... 

The calculated time dependence of the surface temperature and temperature in the depth of QD incorporation (0.15 and 0.3 pm) for different energies shows that the nanocrystal temperature reaches the value of bulk Ge melting temperature at the irradiation energy density of 0.9 J/cm2. The difference in the temperatures of nanocrystals embedded at various depths (0.15 and 0.3 pm) is enlarged with the energy increase. The difference reaches about 100 K under irradiation with... 

Figure 9. Crystalline melting temperatures of the irradiated CL-AGE copolymer(6 mol% AGE) with increasing irradiation dose for the first and second DSC scans.

---