Bio-based cyclized Eucommia ulmoides gum elastomer for promising damping applications

Area of Science:

• Polymer Science
• Materials Science
• Biomaterials

Background:

• Eucommia ulmoides gum (EUG) is a bio-based material structurally similar to natural rubber.
• EUG's high crystallization tendency at room temperature results in a hard plastic, limiting its applications.

Purpose of the Study:

• To prepare a bio-based cyclized Eucommia ulmoides gum (CEUG) elastomer.
• To investigate the effect of cyclization on EUG's properties, particularly its transformation into an elastomer and its damping characteristics.

Main Methods:

• Cyclization of EUG using TiCl4/CH3COOH catalysts.
• Structural analysis using 1H-NMR and FT-IR.
• Thermal and mechanical property evaluation using DSC, XRD, and DMA.

Main Results:

• Cyclization introduced di-, tri-, and tetra-substituted olefins, inhibiting crystallization.
• At 8.2% cyclization, EUG transformed into an elastomer with suppressed crystallization.
• Increased cyclization enhanced glass transition temperature and thermal stability but reduced molecular weight.
• CEUG exhibited tunable damping properties, with tan δmax reaching 1.2 at 20.0% cyclization.

Conclusions:

• CEUG is a promising bio-based elastomer derived from EUG.
• Controlling the degree of cyclization allows for tuning of mechanical and damping properties.
• CEUG is suitable for developing advanced damping materials.