Trinseo's SR unit entering 'new era of sustainability'

Berwyn, Pennsylvania – As Trinseo SA enters its second decade, sustainability has become the single most important focus at the global supplier of raw materials to the synthetic rubber, plastics and latex binder industries.

"Industry and society have reached a pivotal crossroads on the path toward a more sustainable future," Walter van het Hof, global industry affairs and sustainability leader at Trinseo, said in the company's recent 2020 Sustainability Report. 

"Intense consumer and regulatory pressure, rapid climate change, shifting societal norms, the threat of plastics in our oceans and, most recently, the global devastation of Covid-19, have coalesced and thrust us into a new era of sustainability."

Trinseo's synthetic rubber production plant in Schkopau, Germany, which produces both SSBR and ESBR, will be at the heart of these environmental efforts to "close the circle," according to Francesca Reverberi, newly named vice president of engineered materials and synthetic rubber at Trinseo.

The plant supplies about 250,000 tonnes of synthetic rubber per year, of which about 90% goes to the tire industry. As such, sustainability goals need to be established throughout the entire synthetic rubber-to-tire supply chain, and will require collaboration between mid- and downstream players as well as partnerships between raw material competitors at the top, Reverberi said in an email interview.

"The mission to achieve a sustainable future will never be achieved alone," she said. "We understand that the challenge ahead of us is great, and tackling it requires a unified approach from the entire value chain. Like Trinseo, our customers have long-term sustainability strategies and we are dedicated to contributing to the transformation of our industry."

Reverberi noted that many of Trinseo's customers have embraced the use of recycled feedstocks for tires. The work of major manufacturers is helping scale up the amount of rubber from worn tires that can be returned to the value chain rather than entering a landfill.

However, the industrialisation of recycled materials to make synthetic rubber will be a more significant threshold, she said, identifying several pillars toward closing some of the gaps in this circular model for sustainability.

"First and foremost is performance, especially as it relates to reducing greenhouse gas emissions in the tire-use phase due to our focus on rolling resistance reduction," she said. 

"The next challenge is the composition and the way we make our products. We are exploring various options especially in the area of future raw materials, ranging from bio-based to recycled materials ... such as bio-butadiene or recycled styrene monomer.

"We do not just consider the sustainability efforts of our customers and partners, but the overall sustainability impacts and eco-balance of the raw materials we use," she said.

Reverberi joined Trinseo in June 2010, when the company was carved out of Dow Chemical Co. 

She first served as business director of basic plastics and global business director for synthetic rubber, and most recently as global business director of performance plastics.

Her new appointment comes following a recent reorganisation of the executive team at Trinseo designed to "drive efficiency" and make the organisation "flatter."

"In a difficult economic environment, we continue to look for opportunities to drive greater focus on business process optimisation and efficiency," Frank Bozich, president and CEO of Trinseo, said of the restructuring.

The main manufacturing plant for SSBR and ESBR remains in Schkopau, as does Trinseo's SR pilot plant and main R&D centre. As a cost-cutting measure, Trinseo earlier this year decided to close a polybutadiene rubber (nickel and neodymium-PBR) unit in Schkopau by the end of 2020.

Reverberi also leads the company's Engineered Materials business, which has production facilities in Europe and Asia. In that capacity, she will continue to lead her business segments from Horgen, Switzerland, where she has lived with her family for the past 15 years.

Tires drive innovations

SSBR and ESBR find their highest demand in vehicle tires.

SSBR, produced through polymerisation, coagulation and drying/finishing, allows for "very high functionalisation levels" for all types of tires—meaning SSBR allows Trinseo to tailor its products according to the specific performance needs of customers.

Trinseo's SSBR portfolio covers eco tires for small city cars, all the way to ultra high-performance car and SUV tires for all weather conditions. The company's SSBR also is used in tires for light commercial vehicles such as vans and pickup trucks, and in performance motorcycle tires.

"Trinseo applies a batch process, which provides for excellent control over every step in the polymerisation process and allows for very high functionalisation levels," Reverberi said. "Our focus is on ... allowing for very strong interaction between the SSBR and the filler surfaces (such as carbon blacks, silicas) in a rubber compound."

Sustainability plays a major role in these specified demands for SSBR tires, such as low rolling resistance, which ultimately lowers fuel consumption and CO2 emissions, and improved tire safety.

"As more and more tires are being developed with fuel efficiency and sustainability in mind, global SSBR demand has been growing quickly during the past decade at around 8% combined annual growth rate," Reverberi said. "Partnering with our customers, we have been successful in establishing a strong position with our functionalised SSBR in passenger car tire treads, enabling low rolling resistance."

The executive said Trinseo has received increasing interest in SSBR tread applications for heavy commercial vehicles, trucks and buses, especially for regional and long-distance use.

"Low rolling resistance and increased abrasion resistance reduces cost of ownership for long haul/distance applications in the form of lower fuel costs, longer tire life and increased vehicle availability," she said.

ESBR predominantly is used in standard passenger car, agricultural, off-road and two-wheeler tires. The material's good processability and mechanical properties based on high molecular weight – all in combination with a more attractive price – also make it ideal for applications in technical rubber goods, such as sealings, conveyor belts, rubber sheets and hoses, Reverberi said.

"The ESBR production process, simply speaking, is a continuous cold-polymerisation emulsion process, initiated by radicals and carried out in water. The key variables in this process are styrene content and molecular weight whereas the vinyl content is fixed," Reverberi said.

Regardless of the type of synthetic rubber that is required, downstream shifts and manufacturer demands continue to drive sustainable ideas at Trinseo's synthetic rubber plant.

"As far as demands from the tire companies go, they are increasingly searching for solutions that provide greater fuel efficiency, better wet grip and lower noise, which is heavily driven by legislation, especially tire labelling," Reverberi said. 

"In addition, the tire industry is trying to close the loop on circularity and finding solutions to significantly improve the environmental footprint of tires not only during the use phase, which contributes to approximately 90% of greenhouse gases, but also at end-of-life or during tire manufacturing."

Accomplishing this, Reverberi said, will require a paradigm shift in the industry as upstream suppliers of raw materials—all of whom traditionally are competitors—will need to partner to meet these environmental goals.

"I personally believe that increased joint development, more technical collaboration between raw material suppliers and tire manufacturers, is key to technological leaps in the tire industry," she said. 

"Our collaborative approach allows us to adapt our product offerings in accordance with what will best serve the market."

One early example of this is Trinseo's participation in Styrenics Circular Solutions, a joint industry initiative formed by a group of leading styrenics manufacturers in Europe, incorporated in 2018. 

SCS members are united by the common goal: transforming the styrenics industry by maximising polystyrene's value as a fully recyclable material.

"We appreciate that in our industry's sustainability journey we cannot solely focus on passenger cars alone: if we are to truly realise our sustainability goals, we need to increase the use of synthetic rubber in truck and bus tires as well," Reverberi said. 

"To this end, we are educating the sector about the advantages of using functionalised SSBR and are marketing our low Tg polymer range toward customers that plan to have synthetic rubber in tires for heavy duty commercial vehicles."

Looking ahead, electrification remains a key theme in development of both industry technology and methods of sustainability. With countries such as Germany, France and Italy providing attractive financial Covid-19 stimulus packages to purchase new EVs, transformation toward sustainable mobility is accelerated, Reverberi said.

Tire performance requirements for EVs are not revolutionary, but there is a shift in focus, she said. 

"Generally speaking, tires for EVs need to provide enhanced durability, low rolling resistance, riding comfort and noise reduction, while not sacrificing safety performance.

"Especially durability is becoming increasingly important. Not only due to microplastics pollution, but also because of two key aspects that are distinctive to EV abrasion patterns – high torque upon starting the vehicle and higher vehicle weight by several hundred kilogrammes due to the battery packages," she noted.

In EVs, she said, rolling resistance ultimately translates into extended range at a much lower cost than adding battery packages.

"I would like to conclude by emphasising that at Trinseo, sustainability is at the heart of everything we do," Reverberi said. 

"It's worth saying that the term 'sustainability' doesn't mean just one thing: it encompasses a whole range of measures and goals. By partnering with like-minded customers, suppliers and other stakeholders, we are committed to creating innovative and sustainable technologies for this generation and the next."