Preparation of Mechanically Anisotropic Polysaccharide Composite Films Using Roll-Press Techniques

Takuya Sagawa; Yuichi Nikaido; Kazutoshi Iijima; Masahiro Sakaguchi; Yusuke Yataka; Mineo Hashizume

doi:10.1021/acsomega.2c07077

Preparation of Mechanically Anisotropic Polysaccharide Composite Films Using Roll-Press Techniques

ACS Omega. 2023 Feb 1;8(6):5607-5616. doi: 10.1021/acsomega.2c07077. eCollection 2023 Feb 14.

Authors

Takuya Sagawa^{1

2}, Yuichi Nikaido³, Kazutoshi Iijima¹, Masahiro Sakaguchi², Yusuke Yataka¹, Mineo Hashizume^{1

2

3}

Affiliations

¹ Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
² Graduate School of Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
³ Graduate School of Chemical Sciences and Technology, Tokyo University of Science, 12-1 Ichigayafunagawara-machi, Shinjuku-ku, Tokyo 162-0826, Japan.

Abstract

Natural polysaccharides are biocompatible and biodegradable; therefore, they can be used as feedstock for biodegradable structural materials and biomaterials. In this study, anisotropic polysaccharide composite films consisting of chondroitin sulfate C (CS) and chitosan (CHI) were fabricated from their polyion complex (PIC) gels by roll-press techniques. The obtained films (CS/CHI films) were thin and transparent, similar to the composite films prepared by hot-press techniques. The roll-press conditions were optimized, and it was observed that the molecular weight of CHI did not significantly affect the formability of the films, whereas the roll temperature and rolling speed were important. The tensile tests of the roll-pressed films revealed that the mechanical strength of the films in the mechanical direction (MD) was approximately 5 times higher than that in the transverse direction (TD), indicating that the roll-press techniques imparted mechanical anisotropy to the films. Additionally, the films shrank in the MD and expanded in the TD after immersion in aqueous solutions, followed by drying. Such anisotropic shrinking and expanding properties indicate that these films can be used as shape-memory materials.