3.5- Dimethyl-l-hexyn

Polyoxyethylene nonylphenyl ether Polyoxyethylene octylphenyl ether Polyoxyethylene dodecylphenyl ether Polyoxyethylene oleic acid Sorbitan laurate Sorbitan monostearate Dimethyl polysiloxane 2,4,7,9-Tetramethyl-5-decyne-4,7-diol 3,6-DimethyI-4-octyne-3,6-diol 3,5-Dimethyl-l-hexyne-3-ol... 

The kinetics of the reaction of OH radicals with 3,5-dimethyl-l-hexyn-3-ol have been investigated by Wells (2004) using a relative rate method. The value reported at 297 3 K is k = (2.9 0.9) x 10 cm molecule" s . ... 

II-D-17.2. Summary of the Atmospheric Fate of 2-Propyn-l-ol and 3,5-Dimethyl-l hexyn-3-ol... 

The atmospheric lifetimes of 2-propyn-l-ol and 3,5-dimethyl-l-hexyn-3-ol with respect to reaction with OH radicals are estimated to be approximately 1 day and 4 h, respectively. The oxidation mechanism of 2-propyn-l-ol has not been investigated experimentally. It is expected that this reaction proceeds mainly through OH addition... 

Table ll-D-45. Rate coefficients (A , cm molecule s ) for reaction of OH with 2-propyn-l-ol (HC=CCH20H) and 3,5-dimethyl-l-hexyn-3-ol [(CHjlaCHCHaCfOHKCHslC CH]... 

Wells, J.R. (2004), The hydroxy radical reaction rate constant and products of the 3,5-dimethyl-l-hexyn-3-ol, Int. J. Chem. Kinet, 36, 534-544. 

Q -D-ido-Hexopyranoso[6,5,4-de][l,3]oxa2ine, 4,6-dideoxy-5, 6 -dihydro-nomenclature, 1, 31 3-Hexyne, 2,2,5,5-dimethyl-oxidation... 

Acetone reacted with acetylene in methylal (formaldehyde dimethyl acetal) at 5°, in the presence of a 3 7 mixture of NaOH pellets and powdered KOH 2,5-dimethyl-3-hexyne-2,5-diol (startg. m. f. 159). Y 90-95%.—At lower temp., acetylene adds only 1 mole of acetone to give 3-methyl-l-butyn-3-ol. (H. Richet, A. ch. [12] 3, 317 (1948).)... 

Dichloro-2,5-dimethyl-3-hexyne in dry ether added dropwise with stirring during 0.5 hr. to ethereal methylmagnesium bromide, stirring continued 1 hr., finally refluxed 1 hr. 2,5-dimethyl-2,3,4-hexatriene. Y ca. 90%. F. e. s. L. Skattebol, Tetrahedron 21, 1357 (1965) f. method, also cumulenes with an even number of double bonds, s. Tetrah. Let. 1965, 2175. 

The boiling points of 3,3-dimethyl-l-butyne and 1-hexyne are 39.5 °C and 71.3 °C, respectively. Explain why the values are so different for these two isomers. 

For organic peroxide vulcanization, a variety of organic peroxides have been shown to be effective [7]. Such peroxides would include di-t-butyl peroxide dicumyl peroxide t-butyl cumyl peroxide l,l-di(t-butylperoxy)-3,3,5-trimeihyl cyclohexane 2,5-dimethyl-2,5-di(r-butylperoxy)hexane 2,5-dimethyl-2,5-di(r-butylper-oxy)hexyne-3 a,a-bis(t-butylperoxy)diisopropylbenzene t-butyl perbenzoate and t-butylperoxy isopropylcarbonate. In contrast to NBR elastomers where 1-3 phr of peroxide is effective, HNBRs generally require peroxide levels of 5-8 phr for effective vulcanization. As discussed earher, this is due to the very low levels of unsaturation present in the HNBR polymers. The specific peroxide chosen will depend on the process safety desired and the vulcanization temperature to be used. Generally, the most common organic peroxides used in HNBR elastomers are Dicumyl peroxide, such as Varox Dicup 40C from R.T. Vanderbilt, on an inert carrier for vulcanization below 177°C and a,a-bis(t-butylperoxy)diisopropylbenzene, such as Varox VC40KE from Vanderbilt, on an inert carrier for vulcanization above 150°C. 

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