Bimetallic Al(III) Compounds as Catalysts for the Synthesis of Biodegradable Polyesters and Polycarbonates

Abstract

Ethylenediamine bridged benzoxazine proligands were synthesized by a modified Mannich condensation reaction. The reaction of the proligands with two equivalents of AlMe 3 resulted in the formation of dinuclear Al(III) compounds in high yield and purity. When the ligand binds to the Al(III) center, it forms two separate six-membered N,O-chelates with the two Al atoms that resembles the N-alkylated salan moiety. Each aluminum atom adopts a distorted tetrahedral geometry as revealed from the single-crystal X-ray diffraction studies of 1. The catalytic activity of these aluminum compounds was investigated towards the ROP of rac-LA and ROCOP of epoxides (PO, CHO, tBuGE) and phthalic anhydride and ROCOP of CHO with CO 2 . These aluminum compounds showed notable catalytic activity towards the ROP and ROCOP reactions in the absence of cocatalyst.

Chemical Recycling of Polycarbonates via Ammonolysis and Polycaprolactones by KOH‐Catalyzed Methanolysis

“…A popular thermoplastic polymer with superior heat resistance, mechanical strength, and optical clarity is Poly[2,2‐bis(4‐hydroxyphenyl)propane carbonate] (PC; Poly(bisphenol A carbonate 1 ) [9] (Figure 1). It is not biodegradable.…”