Coalesced Poly(ε-caprolactone) Fibers Are Stronger

Abstract

Melt-spun fibers were made from poly(ε-caprolactone) (PCL) coalesced from stoichiometric inclusion complex crystals formed with host urea. Melting and crystallization behaviors, mechanical properties, and the birefringence of undrawn and cold-drawn fibers were investigated. Undrawn coalesced PCL fibers were observed to have 500-600% higher moduli than undrawn as-received (asr) PCL fibers and a modulus comparable to drawn asr PCL fibers. Drawn coalesced PCL fibers have the highest crystallinity, orientation, and 65% higher moduli than drawn asr PCL fibers. Drawn coalesced PCL fibers have only a 5% higher crystallinity than drawn asr PCL fibers, yet they have 65% higher moduli and lower elongation at break values. Clearly, the intrinsic alignment of the coalesced polymers is the reason for their higher moduli and lower elongation, as confirmed by the birefringence observed in drawn coalesced and asr-PCL fibers. The improved mechanical properties of coalesced PCL fibers make them a better candidate for use in tissue engineering as scaffolds.

Concurrent collection and post-drawing of individual electrospun polymer nanofibers to enhance macromolecular alignment and mechanical properties

“…This would indicate that the observed changes in bond activity are related to the absolute magnitude of the draw ratio and not the percentage draw ratio to failure, which occurred at 2.25 for collective mesh samples and 4.5 for automated track drawn fibers. [14,15]). Undrawn fibers collected across parallel plates were 3.6x stronger and 3.2x stiffer than random electrospun meshes collected on flat plates.…”

“…Thus, an important difference between traditional and electrospinning fabrication methods is the lack of an effective solid/semi-solid post-drawing step in electrospinning. This critical process is utilized to increase the strengths of wet and melt spun microfibers by 5-15x [4,[14][15][16]. The addition of a secondary post-drawing step at the collector stage is a logical approach to enhance the macromolecular alignment and mechanical properties of electrospun nanofibers.…”

Preparation and characterization of biodegradable poly(ϵ-caprolactone) self-reinforced composites and their crystallization behavior

“…However, to further extend the practical applications of PCL, i.e. for use for load‐bearing scaffolds, the material must be mechanically enhanced …”

Preparation and properties of poly(ε‐caprolactone) self‐reinforced composites based on fibers/matrix structure

“…1 These unique properties afford PCL high potential as a kind of appropriate substitute for tissue engineering scaffolds. 2 Despite its good biodegradability and biocompatibility, PCL suffers from weak mechanical strength, 3 so PCL has not made great headway as a load bearing implantable material. If PCL could be strengthened by some methods, it may gain new biomedical applications in particular for load-bearing tissue engineering scaffolds.…”

“…The Codes and Molecular Weight of Prepared Polymers APP peak area in DSC traces, and DH 0 is the heat of fusion of the 100% crystalline material, for PCL, which is 135.56 J/g 3. …”