Multifunctional Cyclic Carbonates Comprising Hyperbranched Polyacetals: Synthesis and Applications to Polymer Electrolytes and Networked Polymer Materials

Hyperbranched polyacetals (HBPAs) bearing cyclic carbonate (CC) terminals were synthesized from protocatechuric aldehydes bearing bifunctional trimethylolpropane (TMP) or glycerol (Gly) structures and then utilized to design polymer electrolytes and networked polymer materials. Since TMP-based cyclic acetals (CAs) are thermodynamically more stable than Gly-derived CSs, the copolymerization of these monomers favors to form HBPAs comprising TMP-based acetal stems and Gly terminals. Consequently, HBPAs composed of larger amounts of TMP or Gly terminals were separately synthesized by changing monomer feed ratios. Their diol terminals react efficiently with diphenyl carbonate to give HBPAs bearing 5- or 6-membered CC (5-CC or 6-CC) terminals. HBPAs bearing 5-CC terminals were mixed homogeneously with lithium bis(trifluoromethanesulfonyl)imide to form uniform films showing lithium ion conductivity ranging from 8.2 × 10⁻⁹ to 2.1 × 10⁻³ S cm⁻¹ at 23–80 °C, whereas networked polycarbonate and polyhydroxyurethane films were successfully fabricated using HBPAs having CC terminals. These results apparently indicate that HBPAs having CC terminals are useful scaffolds to design functional polymer materials.