Resumen

AL-MAYAHI, Baqer; AL-LAMI, Hadi  y  HADDAD, Athir. Synthesis of some Nano Multi Arms Polylactide-Dipentaerythritol Organic Polymers. J. Mex. Chem. Soc [online]. 2020, vol.64, n.4, pp.253-263.  Epub 04-Jun-2021. ISSN 1870-249X.  https://doi.org/10.29356/jmcs.v64i4.1182.

The synthesis of a family of polymer stars with six arms of varied poly (L-lactide), PLLA, chain length were prepared to have four various L-lactide monomer repeated units (x=10, 25, 50, and 100) of L-lactide with Dipentaerythritol (DPE) cores support six PLLA arms using 1,8-Diazabicyclo [5.4.0] undec-7-ene (DBU) as an organocatalyst in the ring-opening polymerization (ROP), which afford systematic control the ROP to synthesize polymer stars of variable molecular weight at room temperature. The proposed polymerization mechanism was driven by hydrogen bonding interaction. This is following the fact that DBU does not cause extensive transesterification of PLLA on the time scale of lactide ROP. The well-defined six-armed stars (PLLA) with a DPE core has been proven by FTIR (Fourier-Transform Infrared Spectroscopy), 1H-NMR (Proton Nuclear Magnetic Resonance Spectroscopy), 13C-NMR (Carbon Nuclear Magnetic Resonance Spectroscopy), and GPC (Gel Permeation Chromatography). The analysis of these six-arm polymers confirmed the expected structure of the obtained star-shaped polymers. The molecular weights of D-PLLAx star polymers linearly increased with the molar ratio of monomer to the initiator, and the molecular weight distribution was narrow (Mw/Mn = 1.09-1.13). The scanning electron microscope (SEM) was used to examine the shape and size of the prepared stars D-PLLAx polymeric nanoparticles may form. The micrographs revealed that the nanoparticles with nearly spherical shapes and with different sizes were gained, but in general, they are less than 100nm in diameters as they developed by the Image-J program which may have a great impact on star properties, The simplicity of the reaction conditions, the ready availability of the catalyst, and the exquisite control over the polymerization are demonstrated.

Palabras llave : Organic polymer; dipentaerythritol; nanoparticles; polylactide six arms.

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