Synthesis and molecular characterization of chitosan/starch blends based polyurethanes

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Polyurethanes (PUs) are versatile polymers with broad applications.
• Developing sustainable and functional PUs using natural resources is of significant interest.
• Starch and chitosan offer biocompatibility and biodegradability, making them attractive for PU modification.

Purpose of the Study:

• To synthesize novel polyurethanes modified with starch and chitosan.
• To investigate the effect of starch and chitosan incorporation on PU properties.
• To evaluate the thermal stability and surface morphology of the synthesized PUs.

Main Methods:

• Step-growth polymerization reaction between -NCO terminated prepolymer and chain extenders (1,4-Butanediol/starch/chitosan).
• Synthesis of prepolymer via reaction of Isophorone Diisocyanate (IPDI) with Hydroxyl-terminated Polybutadiene (HTPB).
• Characterization using Fourier Transformed Infrared (FTIR) spectroscopy, Proton Nuclear Magnetic Resonance (¹H NMR) spectroscopy, Scanning Electron Microscope (SEM), and Thermogravimetric Analysis (TGA).

Main Results:

• Successful synthesis of five polyurethane samples with varying ratios of starch and chitosan.
• Surface morphology analysis using SEM revealed distinct surface characteristics.
• Thermogravimetric analysis indicated enhanced thermal stability in PUs containing an equal mixture of starch and chitosan.

Conclusions:

• Starch and chitosan are effective modifiers for polyurethane synthesis.
• The combination of starch and chitosan, particularly at equal amounts, improves the thermal stability of polyurethanes.
• These modified PUs show potential for applications requiring enhanced thermal properties and sustainable material composition.