Preparation and characterization of a bio-based rigid plastic based on gelatinized starch cross-linked with furfural and formaldehyde

Abstract

The extensive use and rapid consumption of energy especially with the shortage of oil-derived resources pushed researchers to focus on developing more biomass-based plastics. The current article presents the possibility to undergo polycondensation of gelatinized starch and corn-derived furfural in presence of formaldehyde under acidic conditions to produce a thermoplastic material, starch–furanic resin. The structure of resulting product was studied intensively using solid-state 13C nuclear magnetic resonance (NMR) and Raman spectroscopy. The glass transitions, molecular weight, and thermal stability of the developed material were investigated with techniques such as differential scanning calorimetry (DSC), gel permeation chromatograph (GPC) and thermogravimetric analysis (TGA). In addition, the morphological features of the material’s surface were studied with scanning electron microscopy (SEM). Moreover, the related properties of the plastic were characterized by the measurements of Brinell hardness and compression resistance. The plastic shows a smooth appearance without crack and bubbles, and exhibited a glass transition temperature as high as 129 °C and a 12% weight loss temperature of 200 ℃ in nitrogen. All these results support that the condensation reactions between the gelatinized starch and aldehydes were more appropriate under acidic conditions to yield more complicated network structure with better homogeneous microstructure, which revealed superior and comparable results to that of phenol-formaldehyde plastics.