Facile synthesis of eight-membered cyclic(ester-amide)s and their organocatalytic ring-opening polymerizations. Issue 31 (20th July 2022)

• Record Type: Journal Article
• Authors: Guo, Yu-Ting; Xiong, Wei; Shi, Changxia; Du, Fu-Sheng; Li, Zi-Chen
• Is Part Of: Polymer chemistry. Volume 13:Issue 31(2022)
• Page Start: 4490
• Page End: 4501
• Publication Date: 2022-07-20
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/d2py00683a
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Facile modular synthesis of eight-membered cyclic(ester-amide)s based on phthalic anhydride and β-amino alcohols and organocatalitic ROP of the monomers to afford degradable semi-aromatic poly(ester-amides)s with tunable thermal properties. Abstract : Five eight-membered cyclic(ester-amide)s (M1–M5 ) were synthesized from phthalic anhydride and β-amino alcohols by sequential nucleophilic addition and intramolecular esterification. The organocatalytic ring-opening polymerization (ROP) of these monomers with 1, 5, 7-triazabicyclo[4.4.0]-dec-5-ene (TBD) and 1, 8-diazabicyclo[5.4.0]undecane-7-ene (DBU)/thiourea (TU) as the catalysts was investigated, and they could all be polymerized in a controlled manner under optimized conditions, affording well-defined poly(ester-amide)s (PEAs) (P1–P5 ) with tailored molar masses and narrow dispersities. The structures of these PEAs were characterized, confirming that the main-chain tertiary amide bonds existed as a mixture of cis / trans isomers. These PEAs are amorphous materials with high thermal stability ( T d, 5% : 260–301 °C) and side chain-dependent glass transition temperatures ( T g s) (62–138 °C). Polymer P1 contains both a rigid benzene ring and a pyrrole ring in the backbone, being a PEA with the highest T d, 5% (301 °C) and T g (138 °C). The TBD-catalyzed copolymerization of M1 and rac -LA could generate a series of random copolymers with tunable and enhanced T g s (52–96 °C) with increasing incorporation ratio of M1 (0–51 mol%). Finally, These PEAs could be selectively and completely converted into their corresponding monomer precursors in alkaline aqueous solutions.