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Publication Citation: Formation of Extended Ionomeric Network by Bulk Polymerization of L,D-lactide with Layered Double Hydroxide

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Author(s): Edward D. McCarthy; Mauro Zammarano; Douglas M. Fox; Ryan C. Nieuwendaal; Yeon Seok Kim; P H. Maupin; Paul C. Trulove; Jeffrey W. Gilman;
Title: Formation of Extended Ionomeric Network by Bulk Polymerization of L,D-lactide with Layered Double Hydroxide
Published: November 22, 2012
Abstract: We report the formation of an ionomeric network in a poly(L,D-lactide) hybrid nanocomposite, (PLDLA-HYB) during in-situ melt polymerization of L,D lactide in the presence of magnesium/aluminium layered-double-hydroxide (LDH) without added catalyst. The effect of LDH mass loading and reaction time on molecular mass and yield of soluble poly(L,D lactide) (PLDLA-SOL) present in the hybrid was investigated for a better understanding of the conflicting roles of LDH in polymerization and degradation of PLDLA-SOL. High molecular mass PLDLA-SOL is obtained through initiation of polymerization by LDH. However an additional insoluble organic-inorganic fraction, INSOL, is also observed within the product when PLDLA-SOL is extracted using methylene chloride as solvent. It is proposed that INSOL is an ionomeric network comprising hydrogen-bonded, or otherwise co-ordinated, lactic acid monomer salts of magnesium, together with PLDLA in a 30 % to 70 % mass ratio.
Citation: Polymer
Pages: pp. 1 - 12
Keywords: Nanocomposite; polylactide; layered double hydroxide; polymer; interface
Research Areas: Green Manufacturing, Polymers, Nanocomposites, Nanomaterials, Materials Science
DOI: http://dx.doi.org/10.1016/j.polymer.2012.11.037  (Note: May link to a non-U.S. Government webpage)