Mechanical properties and thermal stability of intermolecular-fitted poly(vinyl alcohol)/α-chitin nanofibrous mat

Seunghwan Choy; Hyunwoo Moon; Yeonju Park; Young Mee Jung; Jun Mo Koo; Dongyeop X Oh; Dong Soo Hwang

doi:10.1016/j.carbpol.2020.116476

Mechanical properties and thermal stability of intermolecular-fitted poly(vinyl alcohol)/α-chitin nanofibrous mat

Carbohydr Polym. 2020 Sep 15:244:116476. doi: 10.1016/j.carbpol.2020.116476. Epub 2020 May 30.

Authors

Seunghwan Choy¹, Hyunwoo Moon², Yeonju Park³, Young Mee Jung³, Jun Mo Koo⁴, Dongyeop X Oh⁵, Dong Soo Hwang⁶

Affiliations

¹ Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea.
² Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Chengam-ro, Nam-gu, Pohang 37673, South Korea.
³ Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, South Korea.
⁴ Research Center for Bio-based Chemistry, Korea Research Institute of Chemical Technology (KRICT), South Korea. Electronic address: jmkoo@krict.re.kr.
⁵ Research Center for Bio-based Chemistry, Korea Research Institute of Chemical Technology (KRICT), South Korea; University of Science and Technology (UST), Ulsan 44429, South Korea. Electronic address: dongyeop@krict.re.kr.
⁶ Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Chengam-ro, Nam-gu, Pohang 37673, South Korea; Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), 77 Chengam-ro, Nam-gu, Pohang 37673, South Korea; Institute for Convergence Research and Education in Advanced Technology, Yonsei University International Campus, 85, Songdogwahak-ro, 21983, Korea. Electronic address: dshwang@postech.ac.kr.

PMID: 32536401
DOI: 10.1016/j.carbpol.2020.116476

Abstract

The major disadvantage of electrospun nanofibrous mats is their poor mechanical properties, which result from interfibrillar slips, porous structures, and the isotropic conformation of functional groups in fibers. In this work, we develop a tough electrospun mat without cost of both the stiffness and extensibility by combining two mutually exclusive polymers, i.e., generally "ductile" poly(vinyl alcohol) (PVA) and "stiff" α-chitin. The toughness of PVA/α-chitin is considerably higher (∼20 times) compared to PVA via intermolecular-fitted design and stoichiometric balance between hydrogen bonding donors and acceptors. Moreover, consistently oriented functional groups that are perpendicular to nanofibers improve mechanical properties. As a result, stiffness and extensibility are simultaneously increased by ∼19.3 and ∼3.8 times, respectively compared to PVA. The thermal stability with a 2.80-fold larger melting enthalpy of 823.95 ± 7.05 J g^-1 than PVA. The great thermomechanical performance provides an insight for molecular design in electrospun nanofibers with chitin polymorphs.

Keywords: Chitin; Electrospinning; Nanofiber; Particulate matter; Polymorphs; Toughness.