Hydroperoxides molarity determination

It should be noted that reaction 6 does not lead to polymer chain scission ie, there is no molar mass reduction here, in contrast to reaction 5 where there is a molar mass reduction. It should also be noted that the formation and reaction of hydroperoxide groups attached to polymer molecules (reactions 3 and 4) are much slower, ie, rate determining, than the other processes shown. It will be apparent from the free-radical products formed in reactions 1 through 4 that this whole peroxidation procedure is a branching chain reaction. Additive chemistry is required to provide polyolefins with any sort of prolonged service fife, and such chemistry is well known and entirely effective. 

The optimum molar ratio of substrates for UPR synthesis was foimd to be 1.10 0.75 0.30 (glycol maleic anhydride anthracene/cyclopentadiene). Polycondensation reactions were carried out with the addition of xylene, in the temperature range of 140-150 °C. The polyesters were crosslinked with styrene (45 wt %) in the presence of ciunyl hydroperoxide and cobalt naph-thenate. The results of determination of mechanical and electrical properties... 

The individual processes shown above (reactions 3.1 to 3.9) do not by any means represent all the relevant chemistiy that occurs upon the exposure of unstabiUzed polyolefins to heat and/or UV light in the environment. What these equations do emphasize, however, is the involvement of the hydroperoxide groups in the molar mass reduction phenomenon. It must also be emphasized that the formation of these groups is rate-determining in the heat or UV-Iight initiated oxidative degradation. The only major difference between these two types of initiation is that the intermediate ketones that are formed are UV-... 

---