Sarkar lab - Research

A) Upcycling of the polymer waste

Synthetic polymers (plastics) are ubiquitous in almost every aspect of our lives. However, the improper recycling of these plastic materials leads to pollution and economic loss. The situation is so dire that research indicates that by 2050, there will be more plastic in the ocean than fish. Therefore, the suitable end-of-life management of polymers is essential.

In an effort to minimize polymer pollution and conserve resources, our group is developing a strategy for upcycling polymer waste, which involves creating higher-value materials from waste polymers. To achieve this, the waste polymer was chemically degraded to derive monomers, which were then polymerized to obtain sustainable polymers.

Publications

3. "Upcycling of polymer waste to closed-loop recyclable polymers" authored by Sourabh Singh and Ramkrishna Sarkar*, Polymer Chemistry, 2025, 16, 4870-4880 https://doi.org/10.1039/D5PY00858A
2. "Upcycling of Waste PET via Reprocessable Thermoset-like Covalent Adaptable Networks (CANs)" Gupta, V.; Majumdar, S.; Das, D.; Ashish, P. K.; Sarkar, R.* Polymer 2025, 328, 128438. https://doi.org/10.1016/j.polymer.2025.128438

1. Vatsalya, Gupta, and Ramkrishna Sarkar*. Closed-loop Recycling of Covalent Adaptable Network (CAN) Derived from Dopamine and Waste PET, 1. J. Polym. Sci. 2025, 63, 2237–2247. https://doi.org/10.1002/pol.20250313

B) Design of robust yet recyclable crosslinked polymers

Covalently cross-linked (thermoset) polymers are widely utilized in applications such as composites, coatings, adhesives, and electronic encapsulation, due to their excellent mechanical strength, chemical resistance, thermal stability, and electrical insulation. However, their permanent cross-links make reprocessing, recycling, and degradation extremely difficult, resulting in inevitable environmental pollution.

To address this challenge, our group is working on designing of the robust and dynamic exchangeable chemistry that is incorporated into a cross-linked polymer, enabling its recycling, thus minimizing their pollution.

Publications
2. "Benzyl thioether: a dynamic covalent motif for covalent adaptable networks" authored by Vatsalya Gupta and Ramkrishna Sarkar*, Macromolecules, 2025, 58, 19, 10856–10867https://doi.org/10.1021/acs.macromol.5c01290

1. Kumar, P., Gupta, V., Majumdar, S., Patwal, R., Das, D., Ashish, P. K., & Sarkar, R.* Benzyl ether: a dynamic covalent motif for designing a trans-ether based covalent adaptable network (CAN). Chem. Commun. 2025, 61, 5621–5624. https://doi.org/10.1039/D5CC00788G

C) Closed loop recycling of the polymers

The current linear polymer consumption model, i.e., take–make–dispose, results not only in pollution, but also in the loss of the energy embedded in these macromolecules.

To address these issues, our group is currently developing a strategy to design a closed-loop chemical recycling process for the polymer, offering a solution to the challenges associated with the end-of-life management of these materials. The polymers were chemically degraded to recover the monomers, which were then used to synthesize the polymer again. This make-and-break cycle can be repeated indefinitely, enabling a true circular polymer economy.

Publications
2. Closed-loop Recycling of Covalent Adaptable Network (CAN) Derived from Dopamine and Waste PET, Vatsalya, Gupta, and Ramkrishna Sarkar*. J. Polym. Sci. 2025, 63, 2237–2247. https://doi.org/10.1002/pol.20250313

1. "Closed-loop recyclable cross-linked polymeric materials via dynamic transetherification" authored by Pawan KumarϮ, Yashi AgarwalϮ, Soumabrata Majumdar, and Ramkrishna Sarkar*.Chemcomm, 2025, 61,14641-14644. https://doi.org/10.1039/D5CC02506K

D) Research on hydrogel

Hydrogels are a distinctive class of soft, wet, and smart polymers with a three-dimensional crosslinked polymeric network that retains a significant amount of water without dissolving in it. These materials exhibit responsiveness to external stimuli, functioning as smart materials. Hydrogels have garnered widespread attention across multiple fields, including self-healing, smart textiles, actuators, sensors, drug delivery systems, wound healing, and tissue engineering applications. Hydrogels undergo substantial mechanical weakening upon water absorption.

We are currently working towards improving the mechanical properties and functionality of the hydrogels.

Publication: Designing Super Tough, Highly Stretchable, and Multi-Responsive Hydrogels with Self-Healing Properties" authored by Akansha Dixit and Ramkrishna Sarkar*, Polymer, 2025, 338, 129068. https://doi.org/10.1016/j.polymer.2025.129068