Isolation, characterization, and microwave assisted surface modification of Colocasia esculenta (L.) Schott mucilage by grafting polylactide

Abstract

Mucilage (represented as CEM) is abundantly present in Colocasia esculenta (L.) Schott or taro and is a water-soluble neutral polysaccharide that can act as a binder, thickening agent, and matrix agent in the pharmaceutical fields of research. Presence of hydroxyl groups on its surface structure allows chemical modification. This study describes in details the synthesis and characterization of its graft copolymer with polylactide (CEM-g-PLA). The polymerization has performed using both the microwave irradiation and conventional methods. Ring opening polymerization of lactide onto the mucilage carried out in presence of stannous octoate as catalyst in chloroform medium produced CEM-g-PLA copolymer under optimum condition. The structure of CEM-g-PLA copolymers obtained from both the methods were comprehensively characterized for their physicochemical and thermal properties by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD), differential scanning colorimetric (DSC), thermo-gravimetric analysis (TGA/DTG) and Dynamic light scattering (DLS) measurements. Grafting of lactide onto CEM backbone has changed its water absorption capacity, solubility and swelling power, morphology, crystalline structure, and thermal property of the mucilage. The newly synthesized CEM-g-PLA copolymer may find potential applications in wastewater treatment and for sustained and controlled drug delivery systems.