Reference

Chemical relaxation and equilibrium studies of association in aqueous solutions of bolaform detergents

Chemical relaxation and equilibrium studies of association in aqueous solutions of bolaform detergents. 1. Dodecane-1,12-bis(trimethylammonium bromide). Yiv, S.; Kale, K. M.; Lang, J.; Zana, R.Chemical with cas number 1674-82-4 also plays role. (Cent. Rech. Macromol., CNRS, Strasbourg, Fr.). J. Phys. Chem., 80(24), 2651-5 (English) 1976. CODEN: JPCHAX. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) Section cross-reference(s): 46 The self-assocn. of aq. dodecamethonium bromide was studied by chem. relaxation (ultrasonic absorption, T-jump, p-jump, and shock tube), d., conductivity, and emf measurements. No relaxation process was detected and no rapid changes of apparent molal vol., conductivity, and emf were found in the concn. range where micellization was reported to occur by other workers. At <0.1 M the aggregated dodecamethonium ions retain most of their hydration water. Dodecamethonium ion aggregates are very loose and contain only a small no. of monomers. .

Diffusion Limited Chain Transfer in Styrene Emulsion Polymerization: Use of n-Dodecanethiol to Regulate Molecular Weight

Diffusion Limited Chain Transfer in Styrene Emulsion Polymerization: Use of n-Dodecanethiol to Regulate Molecular Weight. Cunningham, M. F.; Witty, T. (Department of Chemical Engineering, Queen's University, Kingston, ON, Can.). Polymer Reaction Engineering, 11(3), 519-540 (English) 2003 Marcel Dekker, Inc. CODEN: PREEEG. ISSN: 1054-3414. DOCUMENT TYPE: Journal CA Section: 37 (Plastics Manufacture and Processing) Low volatility chain transfer agents such as n-dodecanethiol (n-DDT) are important for controlling mol. wt. in the prodn. of polymers contg. styrene. The high reactivity of n-DDT towards the styrenic radical, coupled with its low soly. in the aq. phase, often leads to conditions of diffusion limited chain transfer in which the transport rate of n-DDT from the monomer droplets to the polymg. particles is inadequate to maintain equil. concn. in the particles. The extent to which the particles are "starved" of n-DDT has been studied by measuring n-DDT consumption and mol. wt. during styrene emulsion polymns. Varying surfactant and/or initiator concn. is shown to alter the n-DDT consumption and the mol. wt. profiles. The two-film diffusion theory was applied to our data using monomer droplet and polymer particle measurements.