Synthesis, antibacterial activity, and enzymatic decomposition of bio-polyurethane foams containing propolis

Polyurethane foam (PUF) is formed by reacting sugar, propolis, and polyisocyanate, and then blowing with CO2, formed by reacting polyisocyanate with water. An optimum foaming rate of 1440% was found for 15 wt.% of sugar and 20 wt.% of propolis, and the synthesis and cell structure of polyurethane were analyzed by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Under the optimized conditions, the apparent density and thermal conductivity of the PUF-containing propolis were 0.04 - 0.147 g/mL and 0.028 - 0.029 W/(mK), respectively. The bacterial reduction rate was 92.7% in the PUF containing 20 wt.% propolis. PUF can be broken down by enzymatic reactions in water using invertase. The degradation reaction of invertase was kinetically analyzed. This study showed that eco-friendly polymers can be synthesized using sugar and propolis and decomposed through antibacterial activity and enzymatic green recycling. CO 2022 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.