Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

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



Edward D. McCarthy, Mauro Zammarano, Douglas M. Fox, Ryan C. Nieuwendaal, Yeon S. Kim, P H. Maupin, Paul C. Trulove, Jeffrey W. Gilman


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.


Nanocomposite, polylactide, layered double hydroxide, polymer, interface
Created November 22, 2012, Updated November 10, 2018