Sustainability in the production of new elastomers

Sustainability in the production of new elastomers

Catenaccio: Elastomers are complex structures that have to meet conflicting requirements in addition to being subjected to sustainability goals. Here are some of the solutions on the market

 

What a difficult life for elastomers! They must, to a greater or lesser extent, resist wear and maintain their properties even when facing extreme temperatures as well as chemical and mechanical stress. And if this was not enough, these requirements are increasingly combined with the need to respect the environment in terms of both sustainable raw material sourcing and energy consumption. These conditions have been understood by the industry, which has produced innovative solutions both in the field of materials and technologies.

 

JSR Hydrogenated Polymers

JSR Elastomer Europe, for example, started from a well-known trade-off between wear resistance, which can be improved by increasing the molecular weight, and rolling resistance, which is worsened by this type of formulas. Increasing the number of fillers is another way to improve wear resistance but this comes again at the expense of rolling resistance. To reconcile these conflicting demands, JSR has developed a hydrogenated polymer in which a specific polymerization technology allows the bonds between polymer chains to be controlled and made uniform, which promises to increase wear resistance by 50%. Again, according to JSR, the presence of a single bond after hydrogenation allows for a "freer" rotation of the polymer chains, thus able to twist and create links between them increasing wear resistance. JSR has already started marketing its hydrogenated Styrene-Butadiene Rubber (HSBR) polymer and anticipates applications in a diverse range of tire types. According to the manufacturer, HSBRs contribute to sustainability since they can increase smoothness, reduce the amount of material used and extend life cycle by up to 1.5 times compared to conventional tires. JSR used an atomic force microscope (AFM) to evaluate the structure, which confirmed that the hydrogenated polymer is more uniform and more resistant to ozone degradation.

 

Techsyn technology platform for sustainability

Techsyn is a technological platform for tires born from a partnership between important names as it combines Arlanxeo's synthetic rubbers with Solvay's custom silica and innovative mixing processes proposed by Bridgestone. This platform was launched about a year ago and promises a wear reduction of up to 30% and rolling resistance of up to 6% while preserving the other characteristics of the tires. The development of Techsin involved several teams located globally. Among the activities performed we find the development, testing and industrialization of the new SBR (Styrene Butadiene Rubber), the study and production processes for Modified Silica and validation by Bridgestone for compound development and design, production ramp-up and marketing. Bridgestone is implementing mass production of Techsyn for various tire and vehicle categories taking into account the balance between rolling resistance, wear and wet grip to meet different requirements.

 

Versalis bets on styrenic copolymers synthesized from biodiesel

The project by the Italian company of the ENI group aims to increase the sustainability of styrenic block copolymers (SBCs), a class of elastomers that can be processed like plastics but behave like rubber. Improvements at sustainability level involves monomers, the "blocks" from which copolymers are made; the latter are characterized by having monomers of different types, unlike homopolymers. Versalis uses a biodiesel from which, with cracking processes, it obtains intermediate products and the styrene and butadiene monomers necessary for polymerization. The research team has applied a mass-balance approach certified according to the ISCC+ protocol: this is a widely used standard that certifies sustainability along the entire production chain, starting with the raw materials and biomass. Products can be certified as bio-attributed - BA - if the raw material is made from vegetable material, or as bio-circular attributed - BCA - if the raw material is obtained from vegetable waste. Versalis claims to be able to produce ISCC+ certified biodiesel from which it then obtains SBC and BA and BCA styrene butadiene polymers using conventional plants. These bio-attributed materials have the same composition and performance as polymers produced from fossil-derived raw materials.

 

ETB develops Bio butadiene for tire production

The project of the Russian company ETB, which specializes in catalytic technologies, aims to build plants for the transformation of bioethanol into butadiene, the C4H6 monomer at the base of many elastomers, such as polybutadiene and styrene-butadiene, and rubbers such as nitrile and butadiene-methylstyrene. The idea is to develop both stand-alone and integrated plants at the same sites where fossil-based butadiene is produced. To achieve this goal, ETB has developed a new catalytic system that increases the energy efficiency and bio-butadiene yield of the catalytic process developed by S. Lebedev back in the 1920s. This has resulted in significant improvements in the sustainability of the synthetic rubber production chain, along with benefits for the ethanol industry as well. Furthermore, ETB announced a collaboration with an American company, Trinseo (a global materials solution provider and manufacturer of plastics and latex binders) to explore the production feasibility of the technology, and as part of this, a pilot plant, employing both companies' technology, is planned to produce bio-butadiene from ethanol using ETB's catalyst and a single-stage process. ETB recently signed agreements to establish a facility at a European petrochemical site and has experienced strong demand, from the synthetic rubber industry, for its bio-based monomers.

 

UPM Biochemicals is developing fillers from wood

The German company, which already produces glycol and lignin-based resins, seeks to create fillers through the conversion of sustainably sourced wood. The end product is a Renewable Functional Filler (RFF) suitable for many elastomers, with UPM claiming these fillers can partially or completely replace traditional ones, including carbon black and silica, in various applications such as tires, automotive products, flooring and footwear. Among the advantages we find improved electrical insulation properties and absence of polycyclic aromatic hydrocarbons (PAHs). The density of the material is less than 1.35 g/cm³, which is at least 25% less than traditional fillers used by the rubber industry. UPM confirmed the implementation of programs "at a very advanced stage" with EOs and their Tier 1 and 2 suppliers to approve the product. In October 2020, UPM laid the foundation stone for its biorefinery intended to process wood in Leuna, Germany, and said RFFs will make up a "significant percentage" of the plant's output, which is scheduled to start up in late 2022. RFFs are currently being produced on pilot lines and are already undergoing material testing and product and application development. The company then established a rubber technical centre in Leuna, equipped with modern compounding and testing facilities, and invested in a pilot plant in Finland, larger than the one in Leuna. UPM's latest figures indicate that the company is in contact with more than 40 global rubber component manufacturers and more than 10 companies who are already conducting industrial-scale testing using RFFs.

 

Tyromer chemical free devulcanization

Vulcanizing is a two-sided coin: on the one hand, it gives materials the mechanical performance to create the products we know so well, but on the other hand, it prevents rubber from being easily recovered and reused in new products. Tyromer's devulcanization technology uses twin-screw extrusion to process, after mixing with carbon dioxide and exposing to heat, rubber granulate from ELTs (End-of-Life Tires) and other products into Tire-Derived Products to be blended with virgin rubber and elastomers to create new products. Tires for trucks, including off-road, and passenger vehicles with 15-20% TDP are currently being used in road tests in North America and Europe, and an automotive tire manufacturer is designing a tire compound with 30% TDP. Tyromer is complementing its first plant in the Netherlands with a second plant in Windsor, Canada, to supply a major American brand. With financial support from the Dutch government, a third TDP plant has also been built in the Netherlands to be close to a major European brand.