Hexyl-modified morpholine-2, 5-dione-based oligodepsipeptides with relatively low glass transition temperature. (22nd November 2016)

• Record Type: Journal Article
• Authors: Peng, Xingzhou; Behl, Marc; Zhang, Pengfei; Mazurek-Budzyńska, Magdalena; Razzaq, Muhammad Yasar; Lendlein, Andreas
• Is Part Of: Polymer. Volume 105(2016)
• Page Start: 318
• Page End: 326
• Publication Date: 2016-11-22
• Subjects: Morpholine-2, 5-dione -- Depsipeptide -- Ring-opening polymerization; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2016.10.033
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Oligodepsipeptides (oDPs), alternating copolymers of an α-amino acid and an α-hydroxy acid, are typically created by ring-opening polymerization (ROP) of morpholine-2, 5-dione derivatives (MDs). In general, oDPs exhibit relatively high glass transition temperatures ( T g s) caused by the strong intermolecular H-bonding between amide and ester bonds. So far, it was not reported that variation at α-amino acid moieties in MDs monomers lead to lower T g . Here we explored whether the thermal properties of the oDPs can be adjusted by introducing a hexyl side chain in the α-hydroxy acid part of the MDs. By synthesizing a MD with an atactic pendant hexyl group at position 3, the influence of a modification at position 6 compared to a modification at position 3 towards ROP was investigated. In both cases the atactic bulky side groups hindered the H-bonding between chain segments resulting in a significant reduction of the T g s to a temperature around human body temperature (32 and 36 °C) in contrast to ROP of a MD providing a methyl group at position 3 and a T g ≈ 65 °C. Such oDPs could be interesting candidate materials for biomedical applications such as degradable implants. Graphical abstract: Highlights: Morpholine-2, 5-diones with hexyl-side chains (HMMDs) have been prepared. Kinetics of the ring-opening polymerization of HMMDs were understood. Significant reduction of T g of oligodepsipeptides by hexyl-side chains introduction.