Tunable thermoplastic elastomer gels derived from controlled-distribution triblock copolymers with crystallizable...

Area of Science:

• Polymer Science
• Materials Science

Background:

• Thermoplastic elastomers (TPEs) are crucial triblock copolymers used in various technologies.
• Conventional TPEs typically have glassy polystyrene endblocks and rubbery polydiene/polyolefin midblocks.
• TPE gels (TPEGs) are formed by modifying TPEs with oil, altering their properties.

Purpose of the Study:

• Investigate TPEGs derived from a novel controlled-distribution copolymer.
• Examine the impact of crystallizable polyolefin endblocks and random-copolymer midblocks on TPEG properties.
• Explore structure-property relationships in these unique TPEGs.

Main Methods:

• Fabrication of TPEGs using a novel controlled-distribution copolymer.
• Morphological analysis using electron microscopy and small-angle scattering.
• Thermal and mechanical property characterization, including differential scanning calorimetry and uniaxial strain testing.

Main Results:

• TPEG morphology remained stable up to 40 wt% oil, then transformed significantly at higher concentrations.
• Increasing oil content reduced endblock melting point and crystallinity.
• Mechanical properties, including strain at break and fracture toughness, improved by over 50% with 5-40 wt% oil, reaching 2500% strain at break.

Conclusions:

• The structure-property relationships of these TPEGs are highly tunable by composition.
• TPEGs stabilized by crystallizable endblocks offer a promising alternative for developing ultrasoft, stretchy, and recyclable materials.