Open Access

ARTICLE

Cross-Linking of Sago Starch with Furan and Bismaleimide via the Diels-Alder Reaction

by Henky Muljana^*, Ivana Hasjem, Merianawati Sinatra, Dicky Joshua Pesireron, Michael Wilbert Puradisastra, Ryan Hartono, Kevin Yovan Hermanto, Tony Handoko

Department of Chemical Engineering, Parahyangan Catholic University, Bandung, 40141, Indonesia

* Corresponding Author: Henky Muljana. Email:

Journal of Renewable Materials 2023, 11(12), 4039-4060. https://doi.org/10.32604/jrm.2023.031261

Received 26 May 2023; Accepted 07 August 2023; Issue published 10 November 2023

Abstract

This research paper describes the synthesis of thermo-reversible cross-linking of sago starch by grafting a furan pendant group (methyl 2-furoate) onto the starch backbone, followed by a Diels-Alder (DA) reaction of the furan functional group with 1,1′-(methylenedi-4,1-phenylene) bismaleimide (BM). The proof of principles was provided by FTIR and ¹H-NMR analyses. The relevant FTIR peaks are the carbonyl peak (υ C=O sym) at 1721 cm⁻¹ ; the two peaks appeared after DA cross-linking, i.e., at 1510 cm⁻¹ (corresponding to υ CH=CH BM aromatic rings, stretching vibrations), and at 1173 cm⁻¹ (assigned to cycloadduct (C-O-C, δ DA ring)) while the ¹H-NMR result shows evidence for the presence of a furan ring in the starch matrices (in the range of δ 6.3–7.5 ppm). The crosslinked starch product is indeed thermally reversible, as is evident from the appearance of exothermal (DA, temperature range of 50°C–70°C) and endothermal (retro DA, temperature range of 125°C–150°C) transitions in the DSC thermograms. This paper not only proves the thermal reversibility but also demonstrates that the final product properties (chemical, morphology, and thermal stability) can be tuned by varying the annealing temperature, BM intake, and reaction time.

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