A comparative study on the properties of Eucommia ulmoides gum and synthetic trans-1,4-polyisoprene

The macromolecular structure of EU gum is completely that of trans-1,4-polyisoprene, but STPI contains 0.52% cis-1,4-units and 0.34% 3,4-units, which destroy the regularity of the macromolecule and deteriorates its crystalline property. Thus, the stress-strain curve of STPI greatly differs from that of EU gum.