In Situ Synthesis of Chemically Stable Hybrid Co-Networks of Poly(thioctic Acid) with Fe3+ via Controlled/Living Cationic Ring-Opening Polymerization

Abstract

The novel chemically stable hybrid co-networks (PTA-Fe) of poly(thioctic acid) coordinated with molar content (C_Fe) of 1%∼12% Fe³⁺ generated from [FeCl₄·POH]⁻ can be in situ synthesized via controlled/living cationic ring-opening polymerization of α-thioctic acid (TA) with tert-butyl chloride(BCl)/FeCl₃/isopropanol(POH) initiating system at 0 °C. The polymerizations are all in first order with respect to monomer, initiator and co-initiator. The resulting PTAs with desired molecular weights and relatively narrow unimodal molecular weight distribution can be obtained via quantitative initiation by changing [BCl]₀. The livingness of polymerization without chain transfer and termination is confirmed from the linear relationship between molecular weights of the resulting PTAs and polymer yields and the unchanged average polymer chains during polymerization process by Incremental Monomer Addition and All Monomer In techniques. The possible mechanism of the above polymerization is proposed. Interestingly, it is found that the PTA-Fe hybrids can behave chemically stable during storage at room temperature for 24 months when C_Fe ≥ 6.9%. To the best of the knowledge, it is the first example of in situ green synthesis of PTA-Fe hybrid co-networks with excellent chemical stability. The PTA-Fe hybrids would have potential application in the field of elastomer, adhesive and self-healing materials.