912 K
20 pp.
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TitleThe Morphology of Emulsion Polymerized Latex Particles
Author(s)Wignall, G. D.; Ramakrishnan, V. R.; Linne, M. A.; Klein, A.; Sperling, L. H.; Wai, M. P.; Gelman, R. A.; Fatica, M. G.; Hoerl, R. H.; Fisher, L. W.
Publication DateNovember 1987
Report NumberCONF-871190-1
Unique IdentifierACC0341
Other NumbersLegacy ID: DE88002672; OSTI ID: 5679915
Research OrgOak Ridge National Laboratory (ORNL), TN (USA); Lehigh University, Bethlehem, PA (USA); Hercules, Inc., Wilmington, DE (USA). Hercules Research Center; Eastman Kodak Co., Rochester, NY (USA)
Contract NoAC05-84OR21400
Sponsoring OrgU.S. Department of Energy (DOE), Division of Materials Science; National Science Foundation; Hercules Incorporated, Eastman Kodak Company
Other InformationWorkshop on Neutron Scattering, Los Alamos, NM, USA, 3 - 5 Nov 1987
Subject36 Materials Science; Latex; Molecular Structure; Morphology; Polymerization; PMMA; Polystyrene; Copolymers; Deuterium; Deuterium Compounds; Emulsions; Equations; Methyl Methacrylate; Molecular Weight; Monomers; Neutron Diffraction; Particle Size; Small Angle Scattering; Styrene; Surfaces; Suspensions; Alkylated Aromatics; Aromatics; Carboxylic Acid Esters; Chemical Reactions; Coherent Scattering; Colloids; Diffraction; Dispersions; Elastomers; Esters; Hydrocarbons; Hydrogen Compounds; Hydrogen Isotopes; Isotopes; Light Nuclei; Materials; Methacrylic Acid Esters; Nuclei; Odd-Odd Nuclei; Organic Compounds; Organic Polymers; Petrochemicals; Petroleum Products; Plastics; Polyacrylates; Polymers; Polyolefins; Polyvinyls; Rubbers; Scattering; Size; Stable Isotopes; Synthetic Materials
Related Web PagesVenkatraman Ramakrishnan, Thomas A. Steitz, Ada E. Yonath, and Ribosome
AbstractUnder monomer starved feed conditions, emulsion polymerization of perdeuterated methyl methacrylate and styrene in the presence of preformed polymethylmethacrylate latexes resulted in particles with a core-shell morphology, as determined by small-angle neutron scattering (SANS) analysis for a hollow sphere. The locus of polymerization of the added deuterated monomer is therefore at the particle surface. In similar measurements a statistical copolymer of styrene and methyl methacrylate was used as seed particles for further polymerization of trideuteromethyl methacrylate. The resulting polymer latex was again shown to have a core-shell morphological structure as determined by SANS. SANS experiments were also undertaken on polystyrene latexes polymerized by equilibrium swelling methods, with deuterated polymer forming the first or second step. The experiments covered a molecular weight range of 6 x 10{sup 4} < M < 6 x 10{sup 6} g/mol. For M > 10{sup 6} the molecular weights are consistent with the experimental errors, indicating that the deuterium labeled molecules are randomly distributed in the latex. These results led to the finding that the polymer chains were constrained in the latex particles by factors of 2 to 4 from the relaxed coil dimensions. For M < 10{sup 6} g/mol SANS gave zero angle scattering intensities much higher than expected on the basis of a random distribution of labeled molecules. Several models were examined, including the possible development of core-shell structures at lower molecular weights.
912 K
20 pp.
View Document 

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