Mechanical Properties of Biodegradable Fibers and Fibrous Mats: A Comprehensive Review

Abstract

The growing demand for sustainable materials has led to increased interest in biodegradable polymer fibers and nonwoven mats due to their eco-friendly characteristics and potential to reduce plastic pollution. This review highlights how mechanical properties influence the performance and suitability of biodegradable polymer fibers across diverse applications. This covers synthetic polymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), polycaprolactone (PCL), polyglycolic acid (PGA), and polyvinyl alcohol (PVA), as well as natural polymers including chitosan, collagen, cellulose, alginate, silk fibroin, and starch-based polymers. A range of fiber production methods is discussed, including electrospinning, centrifugal spinning, spunbonding, melt blowing, melt spinning, and wet spinning, with attention to how each technique influences tensile strength, elongation, and modulus. The review also addresses advances in composite fibers, nanoparticle incorporation, crosslinking methods, and post-processing strategies that improve mechanical behavior. In addition, mechanical testing techniques such as tensile test machine, atomic force microscopy, and dynamic mechanical analysis are examined to show how fabrication parameters influence fiber performance. This review examines the mechanical performance of biodegradable polymer fibers and fibrous mats, emphasizing their potential as sustainable alternatives to conventional materials in applications such as tissue engineering, drug delivery, medical implants, wound dressings, packaging, and filtration.

Keywords: biodegradable polymers; centrifugal spinning; electrospinning; fibrous mats; mechanical properties; micro/nanofibers; synthetic and natural polymers; tensile tests.

Figure 9

The chemical structures of silk fibroin [131] (reprinted with permission).

Figure 1

Types of biodegradable polymers and their applications.

Figure 2

Schematics of (a) electrospinning [19], (b) centrifugal spinning [22] (reprinted with permission), (c) melt spinning [23] (reprinted with permission), (d) wet spinning [24] (reprinted with permission), (e) spunbonding process, and (f) melt blowing [25] (reprinted with permission).

Figure 3

Stress–strain curves of hybrid nanofibers (PVA/chitosan) with different AgNP contents: (a–d) 0, 0.25, 0.5, and 1 wt.%, respectively. Images (1), (2), and (3) show the TEM morphology of nanofibers containing AgNPs at 0.25, 0.5, and 1 wt.%, respectively [51]. (reprinted with permission).

Figure 4

Electrospinning and tensile testing setup: (A) rotating mandrel for fiber collection with I-frames; (B) I-frame with fiber mat secured for tensile testing; and (C) a fiber mat in Test Resources universal testing system grips before testing [65] (reprinted with permission).

Figure 5

Mechanical properties of PCL, 50:50 PCL: PLLA blend, and PLLA electrospun fibers following hydrolytic degradation in phosphate-buffered saline solution at 37 °C; (A) Young’s modulus, (B) ultimate tensile strength, and (C) percentage strain [82]. Stars (*) represent statistical significance compared to non-degraded scaffold (time zero). (reprinted with permission).

Figure 6

SEM images of electrospun PCL nanofiber mats exposed to 25 μL of DCM vapor in a closed vial for durations of (A,B) 30 min and (C,D) 60 min; (E) cross section of nanofibers before treatment (arrows show no interfiber bonding); (F) cross section of nanofibers after 60 min (arrows indicate welding at cross points) [102] (reprinted with permission).

Figure 7

Effect of acetic acid concentration on the (A) diameter, (B) strength, (C) elasticity, and (D) stiffness of chitosan fibers [109] (reprinted with permission). “*” indicates p < 0.05 compared the 1 vol% AA.

Figure 8

Tensile results of the ternary sample (PLA-PCL)-BC: (A) ultimate tensile strength of the binary systems and (B) Young’s modulus of the binary systems [125] (reprinted with permission).

Figure 10

SEM micrograph of electrospun silk fibroin (SF) fibers: (a) random orientation; (b) SF 60 with knitted orientation (central angle 60°); (c) SF 60 with knitted orientation (central angle 60°), fixed by methanol immersion; (d) SF 90 with knitted orientation (central angle 90°) [134] (reprinted with permission).

Figure 11

Scanning electron micrograph showing the surface morphology of (A) electrospun nonwoven PHBV fibers and (B) solvent-cast PHBV 2D film [138] (reprinted with permission).

Figure 12

Structure–processing–property pyramid for biodegradable fibers.