The Free-Radical Chemistry of Fluoro Ketones. I. Reaction with Saturated Substrates

Howard, Edward G.; Sargeant, P. B.; Krespan, Carl G.

doi:10.1021/ja00982a026

Cited by 28 publications

(12 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Values of GI vary from about 9 in P E 2 to 11.6 in APP. 0.009 (15) 0.008 (19) 0.008 (24) Figure 2 compares the y-initiated oxidations of APP,* EP copolymers, and PE and shows that GI, GP20,, and G',C=o do not change much with the compositions of the polymers but that GPO~H, a t any dose rate, decreases markedly with increasing ethylene contents of the polymers. GO,, which approximates the sum of these quantities but depends mostly on GpoZH, is nearly as sensitive to composition.…”

Section: Rates and Products Of Oxidation At 45°cmentioning

confidence: 99%

Aging and degradation of polyolefins. III. Polyethylene and ethylene–propylene copolymers

Decker

Mayo

Richardson

1973

J. Polym. Sci. Polym. Chem. Ed.

111

View full text Add to dashboard Cite

synopsisRates of oxygen absorption and formation of oxidation products were determined in ?-initiated oxidations of thin films of high-and lowdensity polyethylene, atactic and isotactic polypropylene, and of three ethylene-propylene copolymers. Radiation yields G for 0 2 absorbed and formation of hydroperoxides depend on dose rates and decrease sharply with increasing ethylene content of the copolymers and moderately with increasing crystallinity of any base polymer. G values for dialkyl peroxide and carbonyl formation, and therefore for chain initiation and termination, do not change much with polymer composition and crystallinity and not at all with dose rates. A few experiments with atactic polypropylene and an amorphous ethylene-propylene copolymer, initiated by di-tert-butylperoxy oxdate, indicate that 37 mole-% of ethylene in the polymer increases the efficiency of initiation and the tendency toward crosslinking. 15,000 102,7008Crystallinity by heat of fusion; a,,, = 427,200; all measured on our film by Dr. J. R.Knox.

show abstract

Section: Rates and Products Of Oxidation At 45°cmentioning

confidence: 99%

Aging and degradation of polyolefins. III. Polyethylene and ethylene–propylene copolymers

Decker

Mayo

Richardson

1973

J. Polym. Sci. Polym. Chem. Ed.

111

View full text Add to dashboard Cite

show abstract

“…(I), CH2 (t,p), JH a =178.8 and OCF2 (t Howard and coworkers reported polyfluoroketones participate in free-radical chain addition reac~iorn with carbon-hydrogen bonds in many substrates including cycloalkanes and dioxanes (56) :…”

Section: The Fluoroalkyl Sulfonyl Fluorides (I) and (Iii)mentioning

confidence: 99%

Monomeric and Polymeric Fluoroalkyl Sulfonyl Fluorides, Sulfonate Salts and Sulfonic Acids for Use as Electrolytes and Coatings

Hamel¹

2000

View full text Add to dashboard Cite

show abstract

“…Let us consider reaction (2) first. There were two reported k2's, namely, k2 = 3.4 X 10l2 exp (-13,90O/RT) sec-l [6,8] and k2 = 1010.5*0.7 exp [(-13,000 f 200)/RT] sec-l [9]. At 293"K, the temperature of our experiments, k2 could be estimated to 1.4 X lo2 sec-l and 6.1 sec-l, respectively.…”

Section: Plot Of [R-1 Versus [Rh]mentioning

confidence: 99%

ChemInform Abstract: AN INDIRECT MEASUREMENT OF THE ABSOLUTE RATE CONSTANT OF THE SELF‐REACTION OF TERT‐BUTOXY RADICALS

Wong¹

1981

Chemischer Informationsdienst

View full text Add to dashboard Cite

No reliable rate constant is available for the self-reaction of tert-butoxy radicals. We have set up a competition between hydrogen abstraction and self-reaction of tert-hutoxy radicals in a flash photolysis electron spin resonance study to extract this information. Experimental values of hydrogen abstraction product radical concentrations under various hydrogen donor concentrations were then compared with theoretically calculated values with different values of 2k4 to obtain the best fit. Hydrogen donors such as cyclopentane, anisole, methyl tert-butyl ether, and methanol were chosen for the study. A value of (1.3 f 0.5) X 109M-1 sec-l for the rate constant of the self-reaction of tert-butoxy radicals has been determined a t 293°K.

show abstract

The Free-Radical Chemistry of Fluoro Ketones. I. Reaction with Saturated Substrates

Cited by 28 publications

References 0 publications

Aging and degradation of polyolefins. III. Polyethylene and ethylene–propylene copolymers

Aging and degradation of polyolefins. III. Polyethylene and ethylene–propylene copolymers

Monomeric and Polymeric Fluoroalkyl Sulfonyl Fluorides, Sulfonate Salts and Sulfonic Acids for Use as Electrolytes and Coatings

ChemInform Abstract: AN INDIRECT MEASUREMENT OF THE ABSOLUTE RATE CONSTANT OF THE SELF‐REACTION OF TERT‐BUTOXY RADICALS

Contact Info

Product

Resources

About