Nov-2023

CO2-derived bio-based polycarbonate: A route towards sustainability (RI 2023)

The continuous depletion of fossil-based feedstock and excessive emission of carbon dioxide (CO₂) has affected the ecological environment and become a significant concern.

Monikangkana Talukdar, Ujjal Haldar, Yogesh P Patil AND Bennet C
HP Green R&D Centre, Hindustan Petroleum Corporation Limited

Article Summary

One way to overcome these problems is to adopt and develop novel green chemical processes based on renewable resources (biomass, CO₂), replace the conventional chemical processes with high energy consumption and pollution, and realise the transformation and upgradation of the chemical industry.

Polycarbonates (PCs) are high-performance tough, amorphous, and transparent engineering plastics that have combined benefits of transparency and optical clarity with exceptional impact resistance, tensile strength and dimensional stability. These characteristics widen its application in the production of protective shields, lenses, food and containers and automotive parts.

Traditionally, PC is synthesised from phosgene and bisphenol A (BPA), a petrochemical feedstock that is an endocrine disrupter likely to cause reproductive, developmental, and other health issues. BPA-free PCs are, therefore, highly desirable, and the use of BPA has been forbidden in food packaging and medical equipment, especially in children’s milk bottles, owing to its chronic toxicity.

The end-use applications such as automotive and aircraft components, optics, and medical equipment of bio-based PC make it a suitable drop-in substitute for synthetic PC. Bio-based PC is possibly expected to take over some market share of PMMA and acrylics because of its high impact resistance and high durability in key end-use industries such as medical, building, and construction.

However, the market growth of bio-based PC is anticipated to be negatively affected due its high manufacturing cost and complex synthesis process. Increasing bio-based PC application scope in glass and automotive components owing to protection from UV light is anticipated to bolster market growth in the foreseeable future.

Asia Pacific was the largest bio-based PC market in 2013 and is expected to witness significant growth in bio-based PC demand owing to increasing bio-based thermoplastics demand in electronics and automotive applications. Another major bio-based PC regional market is Europe, on account of stringent regulations related to the use and disposal of petrochemicals. The market growth of bio-based PC in forthcoming years is expected to be driven by the rapid industrialisation and adoption of bio-polymers in emerging economies such as Brazil, China, India, and Malaysia.

As consumer awareness of environmental issues continues to rise, CO₂-derived bio-based PC is likely to gain traction as a viable solution for reducing plastic pollution and mitigating climate change. Collaborations between academia, industry, and government agencies will play a crucial role in advancing research, scaling up production, and expanding market reach, positioning CO₂-derived bio-based PC as a key player in the sustainable materials market.

The application insights of CO₂-derived bio-based PC represent a remarkable advancement in sustainable materials science. This innovative material, synthesised by incorporating CO₂ as a feedstock into the production process, holds immense potential across various industries. One of its most prominent applications lies in the realm of packaging materials. It offers exceptional durability and barrier properties, making it an ideal choice for creating eco-friendly packaging solutions. It not only reduces reliance on fossil fuels but also minimises the carbon footprint associated with packaging waste. Moreover, this innovative material finds utility in the automotive sector, where it can be employed for manufacturing lightweight and robust components. The ability to reduce vehicle weight contributes to improved fuel efficiency and reduced greenhouse gas emissions, aligning with the global push for greener transportation.

In the field of electronics, CO₂-derived bio-based PC serves as an excellent insulating material due to its high thermal stability. It can be used in the production of electrical components and circuit boards, enhancing the overall performance and longevity of electronic devices while reducing their environmental impact. Furthermore, this sustainable PC has shown promise in medical applications, such as the development of bio-compatible implants and drug delivery systems. Its biodegradable properties make it an attractive choice for creating implants that can safely degrade within the body over time. Its ability to combine environmental sustainability with versatile performance makes it a key player in the transition towards a more eco-conscious and technologically advanced future.

We have developed isosorbide-based PCs using a CO₂-derived carbonate molecule, such as dimethyl carbonate and diphenyl carbonate having high molecular weight. These have been developed via a non-phosgene route using newly found economically viable metal-containing homo- and heterogeneous catalyst systems. Notably, designed catalyst systems showed better performance compared to other well-known metal catalyst, even at mild reaction conditions. In addition, the synthesised PC shows better optical clarity reflected by its low haze value. Overall, an effort has been made to develop a bio-renewable PC, with an approximate reduction of 60% of fossil fuel resources compared to conventional PC and a carbon footprint reduction of approximately 20% based on carbonate source. Thus, the development of CO₂-derived bio-based PC aligns with the growing demand for sustainable materials and the need to reduce the environmental impact of plastic production. As the world seeks innovative solutions to combat climate change and reduce plastic pollution, this technology offers a compelling pathway to greener and more sustainable plastics production.

This short article originally appeared in the 2023Refining India Newspaper, which you can VIEW HERE