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08 September 2023

Synthesis and Characterization of Cyclic Carbonate End-Functional Linear and Star Polyesters via Ring-Opening Polymerization

Well-defined α-(cyclic carbonate), ω-hydroxyl heterotelechelic poly (D,L-lactide)s (PDLLAs) were prepared with good end-group fidelity by ring-opening polymerization (ROP) of D,L-lactide catalyzed by organo catalyst namely, N,N′ dimethyl amino pyridine (DMAP) in conjunction with a renewable, functional bio-based initiator namely glycerol 1,2-carbonate (GC) in bulk at 135 °C with 82% yield. In the case of GC/DMAP catalyzed polymerizations, the HO-PDLLA-COOH series was not observed in MALDI TOF mass analysis unlike as obtained due to transesterification reactions when catalyzed by GC/Sn(Oct)2. Also, cyclic carbonate end-functional 4-arm star poly(ε-caprolactone) (PCL) was prepared via coupling of GC with (PCL-COOH)4 at room temperature in the presence of N,N′-dicyclohexylcarbodiimide (DCC) and DMAP. Quantitative conversion of hydroxyl functionality in (PCL-OH)4 to carboxylic acid and then to cyclic carbonate functionality was achieved with 90% yield for low molecular weight 4-arm star PCL confirmed by NMR, FT-IR, and MALDI TOF mass spectroscopy.

Keywords: Telechelics; Functional initiator; Organo catalyst; Reactive and functional polymers; Ring-opening polymerization (ROP); Poly(D,L-lactide); Poly(ε-caprolactone); Star polyesters


24 July 2023

Creating Shape Memory Polymers from Biobased Resources

Developing polymer materials from biomass is a promising pathway to address serious environmental and resource issues. To date, a series of biobased general polymer materials have been successfully industrialized. However, exploring highly valuable functional polymers and intelligent polymer materials from biomass, such as shape memory polymers (SMPs) and self-healing materials, is still a great challenge. The present review intends to bridge a sustainable pathway for the creation of SMPs from biobased resources. Thus, we first recall some backgrounds of the design principle of SMPs and highlight the biobased monomers or building blocks for SMPs, and then we focus on the main varieties of biobased SMPs to clarify their fabricating approaches, functionalizing strategies, new manufacturing methods and the application potential.

Keywords: Shape memory polymer; Biobased; Vitrimers; Polyesters; 4D printing