Fermentative production of 2-(4-aminophenyl)ethylamine to synthesize a novel heat-resistant biopolyurea

Abstract

The aromatic diamine 2-(4-aminophenyl)ethylamine (4APEA) is a potential monomer for polymers and advanced materials. Here, 4APEA was produced by fermentation using genetically engineered Escherichia coli (Masuo et al.2016). Optimizing fed-batch cultures of this strain produced the highest reported yield to date of 4APEA (7.2%; 3.5 g/L versus glucose) within 72 h. Appropriate aeration was important to maximize production and avoid unfavorable 4APEA degradation. Fermented 4APEA was purified from culture medium and polymerized with methylene diphenyldiisocyanate and hexamethylene diisocyanate to produce polyureas PU-1 and PU-2, respectively. The decomposition temperatures for 10% weight loss (Td10) of PU-1 and PU-2 were 276 °C and 302 °C, respectively, and were comparable with that of other thermostable aromatic polyureas. This study is the first to synthesize polyureas from the microbial aromatic diamine. Their excellent thermostability will be useful for the industrial production of heat-resistant polymer materials.

Keywords: aromatic diamine; biopolymer; fermentation; polyurea.