生体高分子研究

抽象的な

Biodegradable High-Density Polyethylene- Polyester Material

Taylor Stefan

High-density polyethylene (HDPE) is a highly robust and long-lasting substance. Its interior molecular chain arrangement, which is crystalline with additional attraction from van der Waals forces, is what gives it its thermoplastic qualities. The molecules’ chains are entirely made of hydrocarbons. Microorganisms that would be able to destroy the plastic are unable to reach the chains and break them up because of the combination of crystallinity and hydrocarbon content.

We present a new polyester material made from easily available bio-based 1, 18-octadecanedicarboxylic acid and ethylene glycol that have a polyethylene-like solid-state structure and tensile characteristics equivalent to high density polyethylene (HDPE). Despite its crystallinity, high melting point (Tm = 96 °C), and hydrophobic character, polyester-2, 18 is vulnerable to rapid and total hydrolytic destruction in in vitro experiments using isolated naturally occurring enzymes. Under industrial composting settings (ISO standard 14855-1) the material biodegrades with mineralization above 95% in two months. Reference experiments with polyester-18,18 (Tm =99 °C) show that the type of the diol repeating unit has a considerable impact on degradation rates, which may be connected to the density of ester groups in the amorphous phase. Methanolysis depolymerisation suggests that it is suitable for closed-loop recycling [1-5].