TPE/TPV in hi-tech applications

Between thermoplastics, which are easy to process but have limited elastic properties, and elastomers, which have remarkable elastic properties but are more complex to process, TPE (ThermoPlastic Elastomer) thermoplastic elastomers (TPV if the elastomer phase is vulcanizable) are a relatively recent family of materials (the concept first appeared in the 1960s). Their heterogeneous structure, made up of flexible and rigid domains, places them midway between rubber or irreversibly cross-linked elastomers, for their elasticity, and thermoplastics, which are easier to process.

Initially confined to everyday applications, they are gradually diversifying into high-tech markets, either as replacements for conventional cross-linked rubbers, or by exploiting their specific properties.

New families, often referred to as super-TPE and super-TPV , retain the fundamental advantages of TPE and TPV, and enable manufacturing on conventional thermoplastics equipment at much higher throughputs than those achieved with conventional vulcanized rubbers. In addition, they offer the advantages of high-performance vulcanized elastomers (e.g. EVMs, acrylic rubbers, silicones, fluorinated rubbers) and those of engineering plastics (e.g. copolyesters, polyamides, fluoropolymers and other engineering plastics). Generally designed to withstand prolonged exposure to heat and aggressive environments, they fall between engineering plastics and specialty rubbers.

However, we must be aware that super-TPEs cannot yet replace all vulcanizable rubbers in all applications. Automotive tires, for example, are not within their field of application. There is no clear dividing line between TPEs and super-TPEs, as some copolyesters and polyether block amides can be classified as super-TPEs. Special grades of general-purpose and engineering TPEs are processed for particular applications, such as medical.

Markets are as diverse as the automotive, medical, electrical and electronics, oil and gas, construction and public works, water treatment and photovoltaics sectors, where thermomechanical properties, gas impermeability, purity, chemical resistance and ion-exchange capacities are key.

In this article, we take a look at a number of examples that illustrate the benefits, and sometimes the necessity, of turning to global concept/material/process solutions.

See also [AM3400] "Concept,...