TPE Technology & Background Chart

Thermoplastic Elastomers (TPE) behave like a thermoset rubber but are processed like thermoplastics. TPEs are generally soft, compressible materials that exhibit some amount of recovery and elasticity. Most TPEs have combinations of hard and soft phases although some TPEs like POEs are single phase. TPEs are classified according to their chemical structure, performance and cost.

The hard phase in a TPE provides engineering properties such as tensile strength, tear strength, modulus, heat resistance, and chemical resistance. The soft phase provides elastomeric properties such as hardness, flexibility, compression set, permanent set and low temperature performance.

The major TPE classifications include:

• Olefinic
• Styrenic
• PVC
• Engineering Elastomers
• High Performance Elastomers

Olefinic elastomers are TPV, TPO and OBC. TPOs can be produced by compounding polypropylene and an elastomer, usually EPDM or POE, or they can be produced in a reactor with polypropylene and ethylene, propylene, or butene rubber. TPVs are based on polypropylene with EPDM rubber. The EPDM can be partially or fully crosslinked utilizing a phenolic or peroxide based crosslinking agent. OBC’s are olefin block copolymers that have a polyethylene hard segment and a POE soft segment. OBCs have better elastic recovery properties compared to TPOs and TPVs.

Styrenic elastomers are SBS, SIS, SEBS, SEPS. SBS and SIS are lower performance and contain double bonds in their chemical structure. SEBS and SEPS are the hydrogenated versions of SBS and SIS and offer improved performance since they have no double bonds in their chemical structure. There are also alloys of soft styrenic block copolymers that are specially formulated to bond to various substrate materials such as polycarbonate, ABS, acrylic, nylon and polyester.

PVC is not a true elastomer although flexible PVC does have some properties that are TPE like such as flexibility, low modulus and low hardness.

Engineering TPEs are based on thermoplastic urethanes (TPU), copolyesters (COPE), and polyamides (COPA). These products offer higher performance, especially in regards to temperature resistance, fatigue resistance, abrasion, and mechanical properties.

High performance TPEs are primarily fluoroelastomers which offer high temperature resistance and exceptional chemical resistance for very demanding applications.