Exploring the constituents and thermal characteristics of miscanthus floridulus for biomass composites

Abstract

Miscanthus floridulus (MF) possesses notable attributes including high photosynthetic efficiency, rapid growth, robust adaptability, and substantial biomass yield. It is widely researched in fields such as genetics, special materials, bioenergy, and ecological protection. However, the research on the addition of MF for biomass composites remains limited due to the absence of comprehensive analysis concerning the composition, internal molecular structure, and properties of MF. A thorough exploration of the fundamental properties of MF has the potential to broaden their advantages and facilitate the advancement of biomass. This investigation delves into the structural characterization and properties of MF, focusing on its stems, leaves, and tassels. Firstly, the primary constituents of MF comprise cellulose, hemicellulose, and lignin. Cellulose predominates in the stem, exhibiting the highest crystallinity, while lignin content peaks in the tassel with the lowest crystallinity. The leaf falls between these extremes in terms of crystallinity. Secondly, carbon and oxygen elements constitute over 95 % of MF's primary components, alongside trace elements like phosphorus and sulfur. Additionally, chemical structure of MF features abundant characteristic functional groups such as hydroxyl, carbonyl, and benzene rings. Studies indicate that samples with low hemicellulose and high lignin content demonstrate superior thermal stability. Consequently, the stem of MF exhibits optimal low-temperature thermal stability, while the tassel excels in high-temperature conditions. Finally, the data highlights a significant influence in the mechanical properties of polylactic acid materials upon the addition of MF. With a 5 % addition of MF, the tensile modulus and flexural strength of the PLA composite reached their optimal values of 933.91 MPa and 55.28±8.77 MPa, respectively. This research establishes a theoretical groundwork for integrating MF into biomass composite materials.