Study on The Higher-Order Structure and Hydrogen Bonding of Biodegradable Polymer by Low-Frequency Vibrational Spectroscopy
Dian Marlina (a, b)*, Harumi Sato (a)
a) Graduate School of Human Development and Environment, Kobe University
3-11, Tsurukabuto Nada-ku, Kobe 657-8501, Japan
b) Fakultas farmasi, Universitas Setia Budi
Jalan Letjend Sutoyo Mojosongo, Solo 57127, Indoneisa
*157d841d[at]stu.kobe-u.ac.jp
Abstract
Synthetic polymers, including plastic products, are known as one of the most important materials in modern life. They have been widely used in various fields such as energy, information technology, medical, living, and environment. However, most of them cannot be decomposed in the environment causing environmental problems and harmful for living organisms. More than that, the excessive use of synthetic polymer will result in the depletion of irreplaceable natural resources since most of them are made from petrochemical materials. Therefore, development of new biopolymers is expected as a material to replace fuel-based polymers. Among them, chitosan is abundant in nature. Development of polymers with chitosan contributed to solve the environmental and resource depletion problems. It is getting more attention as a new material that mitigate energy waste. Chitosan is a polysaccharide produced by deacetylation of chitin and is extensively used in drug delivery applications. Chitosan is difficult to use industrially because it has high glass transition temperature (Tg) and high crystallinity, and exhibits high elastic modulus and low strain fracture. Therefore, it is necessary to improve their physical properties by blending or copolymerizing with other polymers. Intermolecular hydrogen bonding between chitosan and other polymer molecules is expected to play an important role in stabilizing the higher-order structure. The information related to this interaction can be observed in the low-frequency region (3.3-330 cm-1) using terahertz (THz) and low-frequency Raman spectroscopy. Since low-frequency vibrational spectra are derived from intermolecular and intramolecular interactions, THz and low-frequency Raman spectroscopies can be powerful tools to reveal the formation of higher order structures of not only homopolymer but also polymer blends. In this study, by analysing this low-frequency vibrational spectra, we attempted to elucidate the change in higher-order structure and intermolecular hydrogen bonding formed by polymer blends of chitosan and other polymers.
Keywords: Chitosan, higher-order structure, hydrogen bonding, low-frequency vibrational spectroscopy
Topic: Polymer