Chain Scission Kinetics from Melting

The linear variation of ln[H(t)/H(0)] suggests that the rate of the global chain scission reaction follows first-order kinetics that can be characterized by the following relation  

2°Cmin 1 (PEOl to PE08 have average molecular weight (A4 ) of 4 x 106, 106, 104, 

4 x 102gmol-1, respectively). In the inset are plotted (empty symbols) the ratio of the heat of fusion of each sample to the heat of fusion of the higher molecular weight sample (PEOl). The full symbols represent the evolution of the shift of melting temperature (Tm - Tm(PE01)) as a function of molecular weight. Reproduced from [71], 2006 with permission from the American Chemical Society. 

H(t) is the heat of fusion derived from the area under the DSC peak, (d) Eyring plot for the photo-oxidation (full symbols) and the thermo-oxidation (empty symbols) of PEOl. The full square symbols correspond to an irradiation intensity of 100mWcm 2 and the full circle symbols to 81 mWcm 2. 

Reproduced from reference [71], (c) 2006 with permission from the American Chemical Society. 

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