Abstract

Pea starch and dextrin polymers were modified through the unequal reactivity of isocyanate groups in isophorone diisocyanate (IPDI) monomer. The presence of both urethane and isocyanate functionalities in starch and dextrin after modification were confirmed by Fourier transform infrared spectroscopy (FTIR) and 13C nuclear magnetic resonance (13C NMR). The degree of substitution (DS) was calculated using elemental analysis data and showed higher DS values in modified dextrin than modified starch. The onsets of thermal degradation and temperatures at maximum mass losses were improved after modification of both starch and dextrin polymers compared to unmodified ones. Glass transition temperatures (Tg) of modified starch and dextrin were lower than unmodified control ones, and this was more pronounced in modified dextrin at a high molar ratio. Dynamic water vapor sorption of starch and dextrin polymers indicated a slight reduction in moisture sorption of modified starch, but considerably lower moisture sorption in modified dextrin as compared to that of unmodified ones.

Highlights

  • Starch, as the main reserve source and energy storage of plants, is widely available in agricultural products

  • These results indicate a negligible nitrogen content of unmodified starch (S-control) and dextrin (D-control), but considerable amounts of nitrogen were found in modified samples

  • Pea starch and dextrin were successfully modified with isophorone diisocyanate (IPDI) in order

Read more

Summary

Introduction

As the main reserve source and energy storage of plants, is widely available in agricultural products. This biopolymer has excellent applications in many industrial sectors such as food, textile, pharmaceutical, paper, and biofuel. Most of these applications rely on the colloidal properties of two structurally distinct α-D-glucan components of starch granules, amylose, and amylopectin [1]. Amylose is an essentially linear macromolecule with mostly α(1–4)-linked D-glucopyranosyl units and less than 0.5% of the glucose residues in α(1–6) linkages. Amylopectin is larger than amylose with α(1–4) linked chains and up to about 5% of the glucose residues in α(1–6) branch units [2]. Starch from different sources has different amylose/amylopectin ratios, and this, in turn, has a great effect on thermal behavior, mechanical strength and accessibility of the starch granules to water molecule and other chemical reagents [3,4]

Objectives
Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call