Original Macromolecular Architectures Based on poly(ε-caprolactone) and poly(ε-thiocaprolactone) Grafted onto Chitosan Backbone

Abstract

Polyester and/or polythioester grafted chitosan copolymers were synthesized. For that, poly(ε-caprolactone) (PCL), poly(ε-thiocaprolactone) (PTCL), and their copolymers were first synthesized by ring opening polymerization. Copolymers with caprolactone:thiocaprolactone (CL:TCL) molar ratios of 2:1, 1:1, 1:2 were synthesized. All of the synthesized macromolecular architectures were characterized using different spectral (Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H-NMR), X-Ray diffraction (XRD)) and thermal (Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA)) methods. Grafting was then performed according two distinct routes: (i) using a blend of both homopolymers (PCL and PTCL) or (ii) using pre-synthesized copolymers with controlled CL:TCL ratios. Hexamethylene diisocyanate was used as a grafting/coupling agent through urethane bonds with high yield. Grafting preferentially occurred at sulfur sites. The results indicated that PTCL is more reactive and favorable than PCL for grafting onto chitosan. With the homopolymers blend grafting route, the corresponding materials mostly had a higher PTCL portion than expected. To obtain polyester grafted chitosan with a determined CL:TCL ratio, the copolymer grafting route would yield better results.

Chitosan sponges and polycaprolactone nanoparticles carrying tranexamic acid as hemostatic agent: Synthesis, characterization and bioapplication

“…At oral cavity temperatures, approximately 36.7°C, the tested materials would remain stable. Ünlü, Pollet, and Avérous (2018) [ 28 ] also anticipating that the material would remain stable at body temperature, produced samples of PCL, thiocaprolactone, and chitosan, and obtained similar thermogravimetric results. Huang et al [ 29 ] tested chitosan and PCL dressings that release substances in scars, that is, places where hemostasis should occur; and as in our study, the mass loss events of the materials only started to occur above 250°C.…”

Chitosan-Graft-Polyacrylamide Based Release Systems: Effect of pH and Crosslinking

“…chitin and chitosan portions of the 50% DDA biopolymer form an amorphous block copolymer while 99% DDA is a linear, random semicrystalline copolymer (3). Solubility also increases with increasing DDA; amine groups of the chitosan has a pK value of approximately 6.5 indicating that if the medium pH < 4 chitosan is soluble forming a polycationic structure (3)(4)(5).…”

“…The signal at ca. 899 cm -1 belonged to the anomeric (C1) region of the chitosan indicating β conformation (5).…”

Enzymatic Synthesis of Polyesters and Their Bioapplications: Recent Advances and Perspectives

“…These polymers were then, coupled to chitosan backbone using hexamethylene diisocyanate as grafting/coupling agent. [ 194 ] Another approach using unsaturated polyesters is their use as macromonomers for radical polymerization. This is the case of rigid poly(diisopropyl fumarate), which was reacted with ethyl acrylate, given branch flexibility.…”