Various Topological Poly(tert-butyl acrylate)s and Their Impacts on Thermal and Solution Properties

This study reports the synthesis of acrylate-based polymers with diverse topologies, including cyclic and 8-shaped structures, using a combination of atom transfer radical polymerization (ATRP) and click coupling reactions. The linear and tetra-arm poly(tert-butyl acrylate) (PtBA) polymers with similar molar masses are synthesized via the activators regenerated by electron transfer atom transfer radical polymerization. These polymers are further transformed into cyclic and 8-shaped topologies, respectively, through a click reaction. All topologies possessed similar molar mass are confirmed using ¹H NMR, FT-IR, SEC, and MALDI-TOF mass spectrometry. The influence of macromolecular topology on intrinsic viscosity and glass transition temperature (T_g) is systematically investigated. The findings show that within the PtBA topology series, T_g increases with structural compactness, with cyclic polymers exhibiting higher T_g than their precursors. Additionally, intrinsic viscosity decreases as compactness increases across the various topological macromolecules. These observations highlight the potential of topology as a tool for fine-tuning polymer properties, facilitating the development of advanced materials with specific behaviors in solution and bulk properties.