Research Highlight

Green polymers

doi:10.1038/nindia.2009.80 Published online 6 March 2009

An eco-friendly and cost-effective method to increase production of polymers consisting lactones has been devised. Lactones are used as building blocks to make alkaloids, antibiotics, pheromones and flavour components1.

Researchers used iron and ruthenium chloride catalysts to aid in the bulk production of lactone polymers. Given their permeability, biocompatibility and biodegradability, polymers of lactones have potential biomedical applications. The major obstacle to commercialise such polymerisation is the difficulty in removing catalyst residues and the toxicity associated with them. To find a way out, the researchers selected two metal salts (iron and ruthenium chloride) as catalysts to rev up the yields of lactone polymers.

Three lactones — caprolactone (CL), valerolactone (VL) and butyrolactone (BL) — were studied for polymer formation in the presence of alcohols and metal salts at varying temperatures. CL polymerisation revealed an increase in the molecular weight of the polymer of caprolactone. Under same conditions, VL has greater tendency to undergo ring opening polymerisation reaction.

Both catalysts are potent towards lactone polymer formation. "The overall system is green, eco friendly and environmentally benign since iron is a natural human constituent and these polymers are biodegradable," says lead researcher Debashis Chakraborty from the department of chemistry, Indian Institute of Technology, Madras.


  1. Gowda, R. R. et al. Environmentally benign process for bulk ring opening polymerization of lactones using iron and ruthenium chloride catalysts. J. Mol. Catal. Chem. 301, 84-92 (2009) | Article |