Zeolite‐Assisted Synthesis of Polyborodimethylsiloxane: Enhancing Condensation Efficiency and Supramolecular Network Formation via in Situ Water Removal

ABSTRACT

Polyborodimethylsiloxane was synthesized through the condensation of hydroxyl‐terminated polydimethylsiloxane (PDMS–OH) with boric acid using pre‐activated 3 Å zeolite molecular sieves as in situ water scavengers. Continuous removal of condensation‐generated water promoted Si–O–B bond formation, suppressed hydrolytic back‐reactions, and facilitated efficient network formation under mild conditions. FTIR spectroscopy confirmed the formation of Si–O–B linkages, while GPC and rheological analyses revealed the development of a dynamic supramolecular network exhibiting frequency‐dependent viscoelastic behavior. The progressive increase in viscoelastic parameters during the reaction indicated the formation of reversible boron‐mediated network junctions that govern the material response. These findings highlight the critical role of moisture management in controlling condensation kinetics and network evolution. The proposed zeolite‐assisted strategy provides a simple, environmentally benign, and energy‐efficient approach for the synthesis of dynamic silicone elastomer networks.