Olefinic Thermoplastic Elastomer Gels: Combining Polymer Crystallization and Microphase Separation in a Selective...

Area of Science:

• Polymer Science
• Materials Science
• Soft Matter Physics

Background:

• Thermoplastic elastomer gels (TPEGs) offer versatile properties for advanced elastomer technologies.
• Olefinic block copolymers (OBCs) present a unique multiblock structure distinct from styrenic counterparts.
• OBCs feature crystalline polyethylene hard blocks and poly(ethylene-co-α-octene) soft blocks, enabling microphase separation coupled with hard block crystallization.

Purpose of the Study:

• To investigate the structure-property relationships of olefinic TPEGs (OTPEGs).
• To explore the effects of selective soft block swelling via aliphatic oil incorporation on OTPEG morphology and properties.
• To elucidate the roles of crystallization and self-assembly in determining OTPEG characteristics.

Main Methods:

• Preparation of OTPEGs by incorporating a selective aliphatic swelling oil.
• Morphological analysis using polarized light microscopy and small-/wide-angle X-ray scattering (SAXS/WAXS).
• Thermal and mechanical characterization via differential scanning calorimetry (DSC), rheology, and extensiometry.

Main Results:

• The incorporation of aliphatic oil selectively swelled the soft blocks of OBC-based TPEGs.
• Distinct morphological features were observed and correlated with the degree of soft block swelling and hard block crystallization.
• Structure-property relationships were established, highlighting the influence of self-assembly and crystallization on gel properties.

Conclusions:

• Olefinic TPEGs exhibit unique gel characteristics driven by the interplay of block copolymer self-assembly and hard block crystallization.
• Selective swelling offers a pathway to tune the morphology and properties of these advanced elastomer materials.
• The findings provide valuable insights for designing novel elastomer-based technologies utilizing OBCs.