By a News Reporter-Staff News Editor at Science Letter -- Investigators publish new report on Macromolecular Research. According to news reporting out of Philadelphia, Pennsylvania, by NewsRx editors, research stated, "The room temperature morphologies of twelve precise copolymers based on polyethylene (PE) were studied by solid-state C-13 NMR, DSC, and X-ray scattering. These copolymers feature carboxylic acid, phosphonic acid or 1-methylimidazolium bromide pendants on exactly every 9th, 15th or 21st carbon atom along the linear PE chain."
Our news journalists obtained a quote from the research from the University of Pennsylvania, "The morphologies were categorized by the arrangement of the acid or ionic aggregates into liquid-like, layered, or cubic morphologies. The liquid-like morphology is characterized by an amorphous PE matrix and liquid-like packing of the aggregates, wherein the interaggregate spacing increases with l. both the PE segment length and the pendant size. The layered morphologies typically have a semicrystalline PE matrix and upon stretching become highly anisotropic. Notably, the orientation of the aggregates and the PE crystallites relative to the stretch direction depends on whether the morphology is dominated by PE crystallization, as found for acrylic acid (AA) and phosphonic acid (PA) copolymers, or by the strong ionic aggregates, as found for the 1-methylimidazolium bromide (ImBr) copolymers. Cubic morphologies in these precise copolymers require geminal substitution, PA pendants, and sufficiently long PE segments to allow the aggregates to order."
According to the news editors, the research concluded: "These precise copolymers provide an unprecedented array of morphologies that enable correlations between chemical structure and nanoscale morphologies."
For more information on this research see: Room Temperature Morphologies of Precise Acid- and Ion-Containing Polyethylenes. Macromolecules, 2013;46(22):9003-9012. Macromolecules can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; Macromolecules - www.pubs.acs.org/journal/mamobx)
Our news journalists report that additional information may be obtained by contacting C.F. Buitrago, University of Pennsylvania, Dept. of Mat Sci & Engn, Philadelphia, PA 19104, United States. Additional authors for this research include J.E. Jenkins, K.L. Opper, B.S. Aitken, K.B. Wagener, T.M. Alam and K.I. Winey (see also Macromolecular Research).
Keywords for this news article include: Alkenes, Polyenes, Philadelphia, Pennsylvania, Hydrocarbons, United States, Polyethylenes, Organic Chemicals, Macromolecular Research, North and Central America
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