Why Can PTFE Tape Maintain Its Adhesion Without Failure in High-Temperature Environments?

The PTFE high-temperature tape produced by Jiangsu Aokai New Materials uses silicone pressure-sensitive adhesive, which can work stably at 250°C for a long time. The fundamental reasons lie in the following three points:

1. The Main Chain Consists of Si–O Bonds with High Thermal Decomposition Temperature

The molecular main chain of the silicone pressure-sensitive adhesive in PTFE high-temperature tape has a Si O Si O structure. The bond energy of the Si–O bond is approximately 445 kJ/mol, much higher than the C–C bond (about 348 kJ/mol) or C–H bond (about 413 kJ/mol) in common organic polymers such as acrylates and rubbers.

At high temperatures, C–C bonds easily break and trigger chain degradation, whereas Si–O bonds require much higher energy to rupture. Therefore, the molecular main chain of the silicone PSA remains intact at 250°C, avoiding adhesion loss caused by thermal-oxidative degradation.

2. Chemical Cross-Linking Network Prevents Softening and Flow at High Temperatures

Uncrosslinked silicone rubber turns into a viscous liquid at high temperatures and completely loses cohesive strength. However, the silicone PSA in PTFE high-temperature tape is crosslinked via peroxide crosslinking or platinum-catalyzed addition crosslinking, connecting linear molecular chains into a stable three-dimensional network.

This crosslinked structure allows the adhesive layer to maintain solid elastic behavior at 250°C without melting or flowing like thermoplastic materials. Even with a slight decrease in modulus, it still retains sufficient cohesive strength to resist peeling.

3. Low Glass Transition Temperature (Tg ~ −120°C)

The silicone PSA in PTFE high-temperature tape has a very low Tg (approximately −120°C), meaning its molecular chains remain in a highly elastic state across a wide temperature range from −70°C to 300°C, rather than a brittle glassy state.

Thus, at high temperatures, the adhesive layer neither hardens to lose wetting ability nor softens to excessive flow. It maintains a moderate modulus (storage modulus G’ ≈ 10⁴–10⁶ Pa), which is the optimal window for pressure-sensitive adhesion.

Silicone PSA itself has low surface energy (around 22 mN/m), enabling it to wet low-surface-energy substrates such as PTFE and silicone rubber well even at high temperatures — preventing debonding caused by poor surface energy matching.

The above information is provided by Jiangsu Aokai New Materials Technology Co., Ltd.

For detailed parameters, application scenarios and customized solutions of our full product range — including PTFE high-temperature cloth, PTFE high-temperature tape, PTFE high-temperature mesh belt, seamless belt for laminating machines, single-sided PTFE cloth, high-temperature resistant conveyor belts and high-temperature fiberglass cloth — please contact us via:

· Service Hotline:Mr. Guo 18944819998Mr. Liu 13705266308

Adhering to the service philosophy of professionalism and integrity, we are dedicated to providing you with one-stop solutions and attentive service!