The carbon footprint of products – the total emission of greenhouse gases during their lifetime – is a topic of growing importance. “In Europe, we are striving to reduce the carbon footprint of all products. The challenge for the materials industry is to learn how to reduce a material’s carbon footprint while maintaining its physical, chemical and economic properties”, says Rastogi from his office at the Brightlands Chemelot Campus. “To achieve this goal at Chemelot and UM, we must bring different disciplines together under one roof. We don’t want to compete with other groups around the country, but to complement them in their research. This is the dream that gets me out of bed every morning.”
“Too often I see scientists first develop materials made of biological building blocks, and then start thinking about their possible applications. That is the wrong way around. You don't want a green bottle that leaks because the material it’s made of starts degrading. We must keep in mind that the qualities of the biobased materials we develop, such as their life expectancy, must be comparable with the synthetic material we use today.”
The carbon footprint can be reduced in different ways. Bioethanol, for example, which can be obtained from several natural resources, can produce traditional polyethylene, the polymer used to make plastic bags. Sometimes, redesigning a production process does the trick. With his research group in Loughborough, Rastogi helped to develop ultra-strong tape, Endumax, made of the same material as Dyneema, a polymer used to make bulletproof vests. But unlike Dyneema, the production process does not use solvents. “This environmentally friendly method retains the material’s properties, reduces the investments needed for production and makes the new material economically viable.” The Japanese chemical company Teijin Aramid, where Rastogi is a principal scientist, recently opened a factory in Emmen that commercially produces Endumax.
Also present at the interview is Yvonne van der Meer, Project Leader for Biobased Materials at UM. She explains why the university was keen to join forces with Rastogi: “He is an expert in materials science who has the knowledge and vision needed to replace synthetic with biobased materials without losing their chemical and physical properties. This makes him unique.”
Rastogi’s career started at the University of Bristol. “I was fortunate enough to work with Professor Andrew Keller. He discovered the physics behind polymer science. Eventually, I became his golden boy. He put me on an international stage that brought me to Eindhoven, where I worked with Piet Lemstra, one of the inventors of Dyneema. In Bristol I learned about fundamental science, and in Eindhoven I learned how to translate this fundamental science into technological applications.”
At present, he is trying to understand and manipulate the properties of biological polymers. “I want to unravel the forces that act between the long molecules in a polymer.” The Van der Waals force will be familiar to anyone with high school physics; more complex is the hydrogen bonding prevalent in biopolymers. “We’re now starting to understand how to switch hydrogen bonds on and off by shielding and unshielding them with salts. A spider does the same thing when spinning a web. Inside its body, the spider silk is mixed with salts that render the hydrogen bonds inactive. As soon as the spider excretes the silk, the salt is removed and the hydrogen bonds become active. Only then does the silk get its strong, sticky properties.”
His research has already led to five patent applications for UM, including one on nucleating agents for biopolymers. These are additives that help to control the polymerisation reaction, and thus the quality of polymers.
At Chemelot, Rastogi works with colleagues from institutes like AMIBM (the Aachen–Maastricht Institute for Biobased Materials, a partnership between the universities in Maastricht and Aachen) and InScite (the Chemelot Institute for Science and Technology, a collaboration between Maastricht and Eindhoven universities and DSM).
“Networking and cooperating are the keys to learning in multidisciplinary polymer science. We want to establish collaboration with industrial partners by offering the fundamental knowledge required for niche product development. This is difficult to foster in an industrial environment alone”, says Rastogi. “Therefore, organisations like the Brightlands Chemelot Campus and its partners AMIBM and InScite are important. If we develop strong fundamental knowledge, along with the vision on how to use it in industrial settings, we will even help new industries to make their base at Chemelot.”
Networking is something he seems to be good at: Rastogi currently holds three jobs, one in Maastricht, one in Arnhem and one in the UK. “Each month I work one week in the UK and three weeks in the Netherlands. Of those I spend two days a week in Maastricht and the other three in Arnhem.” Does he also have three homes, or does he just travel a lot? He laughs: “I only have one home and one wife, in Eindhoven actually.”
Sanjay Rastogi (1962) obtained his PhD in physics at Lucknow University in India, before turning his attention to polymer science. He has worked at the universities of Bristol, Eindhoven, Mainz, Loughborough and Maastricht.