Against the backdrop of electronic devices rapidly evolving toward greater thinness and higher performance, material safety and functionality have become critical factors constraining industry development. Thermoplastic polyester elastomers (TPEE), with their distinctive dual rubber–plastic properties, are emerging as a core choice for material upgrades in the electronics sector, driven by breakthroughs in flame‑retardant technologies.

The molecular structure of TPEE endows it with inherent advantages.

TPEE is synthesized via ester exchange reactions among terephthalic acid, 1,4-butanediol (BDO), and poly(tetramethylene ether) glycol (PTMGE). Its molecular chain features a microphase-separated structure, with soft segments (polyether) and hard segments (polyester) that form physical crosslinking points. This architecture endows the material with both the high elasticity of rubber—exhibiting elongation at break as high as 500%–800%—and the processability of engineering plastics, with a melt index ranging from 5 to 30 g/10 min. Additionally, TPEE demonstrates excellent thermal stability, with a long-term service temperature range of −50°C to 130°C, and superior chemical resistance. In the electronics sector, these properties provide an essential material foundation for miniaturized device designs; for instance, mobile phone battery covers must withstand repeated bending at a thickness of just 0.3 mm, and TPEE’s elastic modulus (800–2000 MPa) ensures structural integrity.

A breakthrough in flame-retardant technology addresses key industry challenges.

Traditional flame-retardant materials face two major trade-offs: halogenated flame retardants release toxic gases when burned, while halogen-free systems often result in degraded mechanical properties. TPEE addresses these challenges through innovations in three key areas:

1. Molecular Design Level: DuPont’s 5555HS/5556 series employs aluminum diethylphosphinate modified with aerogel as the primary flame retardant. Its nanoscale porous structure forms a dense char layer upon combustion, enabling the material to achieve UL94 V‑0 rating (self‑extinguishing within 30 seconds at a thickness of 1.5 mm), while also raising the limiting oxygen index to 27%. According to Chongqing Kejufu’s patented technology, the addition of a high‑phosphorus polymer synergist allows the material to maintain structural integrity at elevated temperatures up to 800°C, improving thermal stability by 150°C compared with conventional flame retardants.

2. Process Optimization: The twin-screw extruder’s specialized screw configuration (L/D ratio of 24:1, compression ratio of 3:1) ensures uniform dispersion of the flame retardant. DuPont test data indicate that, at processing temperatures between 170 and 200°C, melt viscosity fluctuations are maintained within ±5%, thereby preventing degradation caused by localized overheating.

3. Composite modification technology: When blended with PBT, adding 0.5% chain extender can increase the impact strength by 40%; when blended with PVC, at a TPEE content of 75%, the brittle‑transition temperature of the blend drops from −25°C to −40°C, meeting the performance requirements of Arctic research equipment.

Application scenarios in the electronics sector continue to expand.

In the consumer electronics sector, TPEE has already achieved large-scale application:

• Mobile phone structural components: DuPont 5555HS is used to manufacture battery covers and, at a thickness of 0.3 mm, passes a 1.2-meter drop test while achieving a 30% weight reduction compared to PC/ABS materials.

• Wearable device: The HTR8441 BK316 model boasts excellent UV resistance, delivering five years of no yellowing in outdoor sports watch straps.

• Cable jacket: Halogen-free, flame-retardant TPEE is used in charging cables for new-energy vehicles and has passed the IEC 60332‑1 vertical flame‑spread test, with smoke density reduced by 80% compared to PVC.

In the industrial electronics sector, breakthroughs in material performance are opening up new opportunities:

• Server cabinets: The enhanced-grade TPEE 5556 boasts a tensile strength of 85 MPa, enabling it to replace metal brackets and achieve a 45% weight reduction.

• Medical devices: Models certified for biocompatibility under ISO 10993 have undergone one million fatigue cycles in surgical robot joint components with no visible cracks.

• Aerospace: The 72220 grade retains 80% of its initial strength at −55°C, meeting the requirements for satellite solar panel deployment mechanisms.

Sustainable development drives technological iteration.

The industry is evolving in three major directions:

1. Eco-friendliness: The recyclable flame-retardant system developed by Kejufu ensures that the material retains over 90% of its mechanical properties after five recycling cycles.

2. Functional Integration: By incorporating graphene modifications, the material maintains its flame-retardant properties while increasing its thermal conductivity to 5 W/(m·K).

3. Intelligent Manufacturing: DuPont has implemented a digital twin system that enables real-time monitoring of extrusion process parameters, reducing the product defect rate from 2% to 0.3%.

According to market research firms, the global flame‑retardant TPEE market is projected to grow from RMB 2.599 billion in 2023 to RMB 4.237 billion by 2029, with a compound annual growth rate of 8.6%. Driven by explosive growth in sectors such as 5G base stations and new‑energy vehicles, TPEE materials—boasting flame retardancy, weather resistance, and lightweight properties—are reshaping the electronics industry’s value chain. This materials revolution not only enhances product performance but also serves as a pivotal force in steering the industry toward greater safety, environmental sustainability, and long-term viability.