Hyperbranched Polyesters: Synthesis, Characterization, and Molecular Simulations

Abstract

New types of hyperbranched polyesters were synthesized by the reaction of 2,2-bis(hydroxymethyl) propionic acid as an AB2-type monomer with pentaerythritol, trimethylol propane, or glycerol as the core moiety. The obtained globular networks were characterized by NMR and MALDI-TOF spectroscopic techniques. Molecular weights determined by MALDI-TOF were confirmed by gel permeation chromatography. Fourier transform infrared (FTIR) spectroscopy was used for the quantitative evaluation of hydrogen bonding as well as to study the structure-property relationship. To investigate the changes and types of intermolecular H-bonding interactions in hyperbranched polyesters with a variation in molecular structure, the deconvolution of FTIR spectra was carried out using Origin 6.0 software through the Gaussian curve-fitting method. Molecular simulations were performed through molecular mechanics and molecular dynamics (MD) calculations using the DISCOVER module. Cohesive energy density, solubility parameters, and surface properties of the hyperbranched polyesters were calculated. Further, vibrational analysis was computed using MD simulations for all the hyperbranched polyesters developed in this work.