Hexagonal-Boron-Nitride-Reinforced Butyl/Chloroprene Rubber Composites for Tire Curing Bladder Applications

Area of Science:

• Materials Science
• Polymer Chemistry
• Rubber Technology

Background:

• Butyl/chloroprene rubber (IIR/CR) compounds are used in tire curing bladders.
• Efficient heat transfer is crucial for optimizing the vulcanization process.
• Current materials may have limitations in thermal management.

Purpose of the Study:

• To investigate hexagonal boron nitride (h-BN) as a thermally conductive filler in IIR/CR compounds.
• To enhance heat transfer efficiency for improved tire curing bladder performance.
• To explore the impact of h-BN on material properties and vulcanization kinetics.

Main Methods:

• Solution mixing of IIR/CR compounds with varying h-BN content (0-33 wt%).
• Vulcanization using a hot press.
• Characterization via moving die rheometer (MDR), thermal conductivity measurements, mechanical testing, and dynamic mechanical analysis (DMA).

Main Results:

• Thermal conductivity nearly doubled at 33 wt% h-BN.
• Reduced scorch time due to accelerated vulcanization onset.
• Increased stiffness and elongation at break, with enhanced stress redistribution.
• Higher storage modulus and intensified Payne effect, indicating a robust filler network.

Conclusions:

• Hexagonal boron nitride (h-BN) incorporation significantly enhances thermal conductivity in IIR/CR compounds.
• This leads to faster, more energy-efficient tire curing processes.
• The addition of h-BN improves mechanical properties and dimensional stability of the bladders.