Guide to Thermoplastic Elastomers Materials and Uses Explained

Imagine a material that possesses the elasticity of rubber and the moldability of plastic, capable of being injection-molded like plastic while remaining recyclable. This remarkable material is thermoplastic elastomer (TPE), a unique class of copolymers or blends that combine thermoplastic and elastomeric properties.

When heated above its melting point, TPE exhibits thermoplastic characteristics, allowing it to be shaped into various forms. Within its designed temperature range, it displays elastomeric properties without requiring vulcanization like traditional rubber. Crucially, this process is reversible, enabling TPE products to be recycled, reprocessed, and remolded – significantly improving material efficiency and environmental sustainability.

Unlike thermoset elastomers, TPE utilizes a distinct crosslinking mechanism that enables it to stretch and recover close to its original shape. This unique molecular structure provides extended durability and a broader range of physical properties compared to more rigid materials.

Since the introduction of the first thermoplastic elastomer in 1959, TPE technology has evolved into six primary commercial categories:

Featuring polystyrene hard segments and butadiene/isoprene soft segments, these materials offer excellent elasticity and processability, though with limited heat and oil resistance. Common applications include footwear, adhesives, and seals.

Composed of polypropylene (PP) and uncrosslinked EPDM rubber, these blends are used in high-toughness applications like automotive bumpers and dashboards.

Through dynamic vulcanization, TPVs achieve superior heat resistance (up to 120°C) and compression set properties, making them ideal for automotive seals and pipe gaskets.

Notable for exceptional tear strength and abrasion resistance, TPUs are widely used in shoe soles, industrial belts, and cable insulation.

Withstanding temperatures up to 140°C, these materials combine chemical resistance with excellent fatigue properties for automotive and industrial hose applications.

Offering outstanding heat resistance and chemical stability, these elastomers are used in specialized applications like aerospace components.

TPEs are primarily produced through two copolymerization methods:

• Block Copolymerization: Creates molecular chains with alternating hard and soft segments
• Graft Copolymerization: Attaches polymer branches to a main polymer chain

TPEs are typically supplied in pellet form for conventional thermoplastic processing equipment, allowing for easy coloring and efficient production cycles as short as 20 seconds.

• Energy-efficient production without vulcanization
• Excellent colorability
• Wide temperature resistance (-30°C to +150°C)
• Full recyclability and potential for 3D printing filament
• Superior mechanical properties including tear resistance and flexibility
• Compatibility with co-injection and co-extrusion processes

While offering numerous advantages, TPEs have some constraints:

• Limited high-temperature performance
• Restricted availability in very soft grades
• Requirement for material drying before processing
• Higher cost compared to conventional plastics
• Potential for creep under sustained stress

TPEs have become ubiquitous across multiple industries, including:

• Automotive components (airbag covers, seals)
• Consumer goods (grips, handles)
• Electrical insulation (cables, wires)
• HVAC systems
• Medical devices (tubing, respiratory equipment)

TPEs are increasingly replacing traditional materials in healthcare applications due to their:

• Biocompatibility and chemical inertness
• Range from gel-like to semi-rigid hardness
• Ease of processing into films, sheets, or tubes
• Optical clarity options

All TPEs share three fundamental properties:

1. Reversible elastic deformation
2. Melt-processability at elevated temperatures
3. Minimal creep behavior

The recyclability of TPEs presents significant sustainability advantages over conventional rubbers, aligning with growing environmental concerns in material selection.