Thermoplastic Elastomers (TPEs) represent a versatile group of polymers with virtually limitless applications, owing to their unique blend of properties that bridge the gap between traditional plastics and rubbers. They offer the flexibility and resilience of rubber, coupled with the processability and recyclability of plastics. TPEs find extensive use across various industries, including automotive, electronics, construction, household products, medical devices, and personal items.
TPEs can be broadly categorized into two types: blends and synthetic TPEs.
Blended TPEs: These are produced by combining a soft and flexible polymer, typically rubber, with a thermoplastic material. The processability of the TPE is derived from the thermoplastic component, while the softness and mechanical properties are influenced by the rubber component. The choice of rubber types, thermoplastics, and additives depends on the desired properties and intended application. Blended TPEs can be processed using standard plastic processing equipment and are produced in industrial extruders by compounding factories.
Thermoplastic Vulcanized (TPV) is a specific type of blended TPE where the rubber phase is cured to enhance mechanical properties like a lower compressive set. However, this curing process does not affect the processability of the TPE.
Synthetic TPEs: These are created by chemically bonding flexible monomers (soft block segments) with rigid monomers (hard block segments). The soft block segments determine the flexibility of the TPE, while the hard block segments influence the mechanical properties and processability. Synthetic TPEs are produced in chemical reactors by petrochemical units.
The primary groups of synthetic TPEs include:
TPS (Styrenic Block Copolymers): Examples include SBS (Styrene-Butadiene-Styrene), SEBS (Styrene-Ethylene-Butadiene-Styrene), and SIS (Styrene-Isoprene-Styrene).
TPU (Thermoplastic Polyurethane): TPU is renowned for its excellent abrasion resistance, toughness, and flexibility. It finds applications in footwear, hoses, tubing, and more.
TPEE (Thermoplastic Co-polyester): TPEE offers good chemical resistance, low-temperature flexibility, and high tensile strength. It is commonly used in automotive parts, electrical connectors, and industrial applications.
COPA (Thermoplastic Polyamides): COPA provides high-temperature resistance, mechanical strength, and excellent impact resistance. It is used in automotive components, electrical connectors, and consumer goods.
The advantages of TPEs over traditional rubbers and plastics include cost-effective and straightforward production, recyclability, colorability, suitability for contact with food and the human body, resistance to light, heat, and fire in special grades, and the ability to customize physical-mechanical properties over a wide range.
Due to their versatile properties, TPEs continue to gain popularity and have become indispensable in numerous industries, particularly in applications where both flexibility and processability are paramount.