Crosslinking of Electrospun Fibres from Unsaturated Polyesters by Bis-Triazolinediones (TAD)

Abstract

Crosslinking of an unsaturated aliphatic polyester poly(globalide) (PGl) by bistriazolinediones (bisTADs) is reported. First, a monofunctional model compound, phenyl–TAD (PTAD), was tested for PGl functionalisation. 1H-NMR showed that PTAD–ene reaction was highly efficient with conversions up to 97%. Subsequently, hexamethylene bisTAD (HM–bisTAD) and methylene diphenyl bisTAD (MDP–bisTAD) were used to crosslink electrospun PGl fibres via one- and two-step approaches. In the one-step approach, PGl fibres were collected in a bisTAD solution for in situ crosslinking, which resulted in incomplete crosslinking. In the two-step approach, a light crosslinking of fibres was first achieved in a PGl non-solvent. Subsequent incubation in a fibre swelling bisTAD solution resulted in fully amorphous crosslinked fibres. SEM analysis revealed that the fibres’ morphology was uncompromised by the crosslinking. A significant increase of tensile strength from 0.3 ± 0.08 MPa to 2.7 ± 0.8 MPa and 3.9 ± 0.5 MPa was observed when PGI fibres were crosslinked by HM–bisTAD and MDP–bisTAD, respectively. The reported methodology allows the design of electrospun fibres from biocompatible polyesters and the modulation of their mechanical and thermal properties. It also opens future opportunities for drug delivery applications by selected drug loading.

Click chemistry strategies for the accelerated synthesis of functional macromolecules

“…This is an opportunity as main reaction partner of TAD are alkene and electron rich aromatic systems, which are abundant in both natural and synthetic polymers. TAD crosslinking applications can therefore involve (i) Alder-ene reaction with polymer containing isolated alkene 180,492,493 or indole, 177,178 (ii) DielsÀAlder reaction 494 with polymer containing conjugated diene, 174,180,181,494,495 and (iii) electrophilic aromatic substitution with phenol in polypeptide containing tyrosine derivatives. 172 The reversible bond between indole and TAD in Alder-ene reaction has inspired the "transclick" concept.…”

“…Similarly, a range of unsaturated polyesters, 174,492 poly(glycidyl ether)s 180 and polycarbonates 181 were synthesized by organocatalyzed ROP followed by quantitative and irreversible functionalization with TAD.…”

“…Diene‐rich polymers synthesized via ADMET 495 and ROMP 588 were also shown to be easily functionalized with substituted TAD compounds efficiently without additives. Similarly, a range of unsaturated polyesters, 174,492 poly(glycidyl ether)s 180 and polycarbonates 181 were synthesized by organocatalyzed ROP followed by quantitative and irreversible functionalization with TAD.…”

Fabrication and Photocatalytic Properties of Electrospun Fe-Doped TiO2 Nanofibers Using Polyvinyl Pyrrolidone Precursors

“…To use these various structures effectively, many studies have been conducted such as a biocompatible drug delivery system with antibacterial activity [ 55 , 56 , 57 , 58 , 59 ]. Additionally, various types of structures using nanofibers can be fabricated through after-treatment methods such as calcination [ 60 ] and cross-linking [ 61 , 62 , 63 ].…”

Effect of POSS-Modified Montmorillonite on Thermal, Mechanical, and Electrical Properties of Unsaturated Polyester Nanocomposites

“…Lots of research has been undertaken in inclining the blooming area of clay polymer technologies towards commercial applications [ 1 , 2 , 3 ]. Unsaturated polyester (UP) resins form the crux of thermosets capable to fabricate lightweight composites possessing admirable process ability, durability, and flexibility [ 4 , 5 ]. UP has a vital role in invigorating the tendency of clay polymer nanocomposites to be utilized as high-performance materials in an extensive range of products such as automobiles, construction and building materials, and electrical appliances [ 6 , 7 ].…”