Review on extraction, characteristic, and engineering of the Eucommia ulmodies rubber for industrial application

Eucommia ulmoides rubber (EUR) is a high-molecular polymer of trans- 1,4-polyisoprene, conventionally synthesized by a sequential condensation of isopentenyl diphosphates to its isomer of dimethylallyl diphosphate in trans configuration. The extraction methods for EUR generally include mechanical method, alkali extraction, solvent extraction, and microbial method. Compared with others, microbial method can obtain higher purity EUR and retain its original appearance furthest with less environmental pollution as well as less production cost, implying that it might become the primary extraction technology. EUR has dual characteristics of rubber and plastic. The utilization of EUR is highly dependent on the crystallinity and crosslinking degree which can be modified by physical or chemical methods, to help producing the EUR industrial products that can have multi-functionalities. The objective of this review is to investigate the recent insights of the biosynthesis, extraction, the structure and properties, the modification as well as application of EUR to promote the research and utilization of EUR, to meet the requirements of various engineering applications. EUR is expected to partially substitute natural rubber with broad prospects for development and utilization. • Eucommia ulmoides rubber (EUR) is high molecular polymer of trans-1,4-Polyisoprene. • Various physicochemical methods for EUR extraction are reviewed in this work. • EUR possess the dual characteristics of rubber and plastic. • Industrial application of EUR is highly dependent on the crystallinity and crosslinking degree. • Various EUR based engineering materials are clarified.