Tensile testing and fracture mechanism analysis of polyvinyl alcohol nanofibrous webs

Abstract

A tensile properties testing study was conducted to understand the influence of thickness, cross-head speed (speed of testing), gauge length (GL; specimen test length), and sample shape on important tensile properties of polyvinyl alcohol (PVA) nanofiber webs. The effects of each testing parameter on load at break, extension at break, Young's modulus, and tensile stress-strain curve of PVA nanofiber webs are analyzed. The Welch two sample t-tests show the significant difference among tested data. Using interaction plots, two-way analysis of variance, and margin mean plots, the interaction effects among testing parameters have been analyzed. Of all the factors, cross-head speed, the interaction among GL, and sample thickness (GL: Thickness) and the interaction among GL, testing speed and sample thickness (GL: Speed: Thickness) have significant influence on the tensile properties of PVA nanofiber webs. Moreover, the hypothesized model of mechanism of tensile strain-stress curve of PVA nanofiber webs has been proposed. Based on the model, the tensile strain-stress curve can be split into three stages: linear elastic, partial break up, and complete breakage. This study will provide a better understanding of tensile testing parameters' effects and their interaction effects on the tensile properties of nanowebs.

Effect of Test Parameters on Sensitivity of Tensile Test Results for Greige Cotton Hydroentangled Nonwoven Fabric

“…This because of the increased bonding structure and fiber nodes. These testing results matched the mechanism with our previous results about nanofiber webs [18]. This study's mechanisms of testing speed, angle to machine direction, and specimen width are not clear due to the multifactor experiment.…”

“…As is shown in Table 4, the R 2 of most regression equations is around 0.8 ( L : 0.83, Ex : 0.85, Sa : 0.77, M : 0.88, En : 0.85), which means that there is a strong positive relationship between testing parameters or sample characteristics and tensile results; therefore, the parameters have obvious influence on these five tensile properties. Comparatively, the R 2 of tensile stress is 0.70, which is much lower than the other R 2 ; a study by Lou et al 17, 18 showed that an R 2 of 0.70 possibly indicates the influence of interactive effects or inherent fiber factors (e.g. molecular weight or viscosity).…”

Novel polycaprolactone (PCL)‐type I collagen core‐shell electrospun nanofibers for wound healing applications

“…This is attributed to its elastomeric behavior at room temperature due to its low glass transition temperature ( T g = −60°C) 43 . This mechanical behavior allows electrospun films to have an elastic modulus compared to the skin 44–46 . In previous studies developed in our group, 47 the preservation of the main structure of type I collagen (triple helix) was observed in Col_1/poly(vinyl alcohol) (PVA) electrospun monolithic nanofibers when an acid solvent system composed of acetic acid/ultrapure water was used.…”

“…43 This mechanical behavior allows electrospun films to have an elastic modulus compared to the skin. [44][45][46] In previous studies developed in our group, 47 the preservation of the main structure of type I collagen (triple helix) was observed in Col_1/poly(vinyl alcohol) (PVA) electrospun monolithic nanofibers when an acid solvent system composed of acetic acid/ultrapure water was used. However, it was seen that monolithic fibers were solubilized after a few hours in contact with saline solution.…”

Preparation of surface-functionalized electrospun PVA nanowebs for potential remedy for SARS-CoV-2

“…Methods described by Turaga et al (2016) and Lou et al (2020) were used in the present study with slight modifications. Briefly, multiple 10% PVA solutions (w/v) were prepared by dissolving 5 g of PVA in 45 mL deionized water at 80°C for 3 h with intermittent stirring.…”