Thermal shrinkage of electrospun PVP nanofibers

Abstract

This paper outlines the shrinkage of electrospun polyvinylpyrrolidone (PVP) fiber mats during thermal treatment. The thermal behavior and phase changes within the fibers were investigated by DSC and TGA/DTA. Five precursors with different PVP loading in ethanol were electrospun. The mats shrinkage as function of temperature was measured in the RT–200 °C range. Shrinkage rate drastically increased above the polymer glass transition point, Tg (150–180 °C), due to increase in polymer chain mobility. Mats shrinkage at 200 °C as function of PVP concentration showed a minimum at ∼10%wt. Below 10% PVP the mats morphology is non‐uniform, consisting of beads and fibers. Above 10% PVP, only flat and uniform fibers were observed. This paper outlines the dominant mechanism governing the mats shrinkage during heating. In addition, the effect of PVP concentration on the expansion of fibers diameter was investigated and found to be consistent with the linear shrinkage observing a minimum at ∼10% PVP. The effect of applied voltage on mat shrinkage was investigated, and showed a minimum at 12 kV. Understanding the interplay between fibers morphology and thermal shrinkage allows precursor composition and system optimization needed for minimizing shrinkage negative effects on the structure and properties of electrospun fiber mats. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 248–254

Electrospun poly(d,l‐lactide)/gelatin/glass‐ceramics tricomponent nanofibrous scaffold for bone tissue engineering

“…As observed for gelatin gels studied in ethanol concentrations >40% vol/vol, the volume shrinkage can reach values from 25 to 50% (Boral, Gupta, & Bohidar, ). In the case of microfiber shrinkage, a decrease in fibers length translates into an increase in fibers diameter (Elishav, Beilin, Rozent, Shter, & Grader, ).…”

Lamellar-like Electrospun Mesoporous Ti-Al-O Nanofibers

“…All the fiber components are uniformly distributed in the ES precursor solution (II-IV), as well as in the dried fibers prior to thermal treatment, as shown in Figure 1a. At a low PVP content (Solution I), few scattered beads are formed (Figure 1b) [14]. Further decrease of the PVP content resulted in an unspinnable precursor.…”

Synthesis and characterization of alumina fibers using solution blow spinning

“…The weight loss observed at around 500 °C and the exothermic peak at this temperature were associated with the combustion of PVP carbonaceous residue. PVP degraded basically in two stages: one between 220 and 430 °C related with the degradation of the side chain of PVP, and other between 450 and 550 °C resulted from the oxidation and decomposition of polymer residues [18][19][20][21][22][23]. Moreover, above 550 °C mass losses did not occur and only the polymorphic alumina transformations took place.…”