Calix[6]arene-Based Interlocked Inverse Vulcanizate Enabling Network-Interface Cooperative Reinforcement in Natural...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Conventional sulfur vulcanization of unsaturated rubbers has limitations in simultaneously enhancing mechanical properties, durability, and aging resistance.
• Developing scalable strategies for high-performance elastomer composites remains a significant challenge.

Purpose of the Study:

• To engineer mechanically interlocked polysulfide cross-linkers using a calixarene-mediated inverse vulcanization approach for natural rubber/carbon black composites.
• To investigate the role of interface integration and macrocyclic systems in improving composite performance.

Main Methods:

• Utilized calix[6]arene derivatives, including tert-butylcalix[6]arene (TBC6) and allyl-functionalized calix[6]arene (ATBC6), in an inverse vulcanization process.
• Designed macrocyclic systems to control rubber-filler interfacial interactions and cross-link network architecture.
• Fabricated natural rubber/carbon black (NR/CB) composites and evaluated their mechanical properties, fracture toughness, and aging resistance.

Main Results:

• The allyl-functionalized calix[6]arene (ATBC6) composite demonstrated a 140% increase in tear strength and a 340% enhancement in fracture toughness compared to conventional vulcanizates.
• The ATBC6-based strategy promoted efficient stress transfer, suppressed crack propagation, and exhibited strain-rate hardening and improved energy absorption.
• Stable polysulfide linkages and phenolic units within the ATBC6 system imparted enhanced thermo-oxidative aging resistance.

Conclusions:

• The calixarene-mediated inverse vulcanization approach offers a scalable strategy for creating high-performance elastomer composites.
• Interface engineering via macrocyclic cross-linkers significantly enhances mechanical properties and durability of natural rubber composites.
• This method provides a practical pathway toward advanced rubber materials with improved tear resistance, toughness, and aging performance.