Simultaneous Enhancement of Strength and Toughness of PLA Induced by Miscibility Variation with PVA.

Yanping Liu,Hanghang Wei,Nan Tian,Qian Li,Zhen Wang

doi:10.3390/polym10101178

Yanping Liu, Hanghang Wei + Show 3 more

Open Access

https://doi.org/10.3390/polym10101178

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Abstract

The mechanical properties of poly (lactic acid) (PLA) nanofibers with 0%, 5%, 10%, and 20% (w/w) poly (vinyl alcohol) (PVA) were investigated at the macro- and microscale. The macro-mechanical properties for the fiber membrane revealed that both the modulus and fracture strain could be improved by 100% and 70%, respectively, with a PVA content of 5%. The variation in modulus and fracture strain versus the diameter of a single electrospun fiber presented two opposite trends, while simultaneous enhancement was observed when the content of PVA was 5% and 10%. With a diameter of 1 μm, the strength and toughness of the L95V5 and L90V10 fibers were enhanced to over 3 and 2 times that of pure PLA, respectively. The structural evolution of electrospun nanofiber was analyzed by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Although PLA and PVA were still miscible in the concentration range used, the latter could crystallize independently after electrospinning. According to the crystallization behavior of the nanofibers, a double network formed by PLA and PVA—one microcrystal/ordered structure and one amorphous structure—is proposed to contribute to the simultaneous enhancement of strength and toughness, which provides a promising method for preparing biodegradable material with high performance.

Highlights

Over the past several decades, poly (PLA) has attracted increasing attention because of its biological properties and renewability [1,2]
Results and Discussions morphology and dimension are influenced by many factors, such as the distance between tip and Considering the fiber quality, four weight ratios between PLA and PVA were chosen as 100:0, collector, solvent viscosity, dielectric constant, and so on
PLA/PVA with in this between PVA and PLA was first checked by differential scanning calorimetry (DSC), and it is this work

Summary

Introduction

Over the past several decades, poly (lactic acid) (PLA) has attracted increasing attention because of its biological properties and renewability [1,2]. PLA products with good mechanical strength are widely used, especially as fixation devices in the biomedical field, such as sutures, pins, scaffolds, and drug delivery devices [3]. The applications of PLA-based products are often restricted due to the lack of suitable mechanical properties, such as flexibility and plasticity. Many studies have been conducted to improve the mechanical properties, and the most common way is by adding plasticizers or other polymeric materials to PLA, such as kenaf fibers, wood pulp, cassava, poly(ε-caprolactone), polyethylene glycol, and so on [4,5,6,7,8,9,10]. Two additional key issues that need to be considered further when choosing reinforcing material for use in biomedical

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