Synthesis and characterization of biopolyurethane crosslinked with castor oil-based hyperbranched polyols as...

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Materials

Background:

• Developing efficient thermal energy storage (TES) materials is crucial for renewable energy integration.
• Polymeric solid-solid phase change materials (SSPCMs) offer advantages like stability and tunable properties.
• Bio-based materials are increasingly sought after to reduce environmental impact.

Purpose of the Study:

• To synthesize novel crosslinking bio-polyurethane based SSPCMs using castor oil (CO) based hyperbranched polyols.
• To investigate the influence of different crosslinkers and diisocyanates on the thermal properties and stability of the SSPCMs.
• To evaluate the potential of these novel SSPCMs for thermal energy storage applications.

Main Methods:

• Synthesis of CO-based hyperbranched polyols via thiol-ene click reaction (COM and COT).
• Fabrication of SSPCMs using a two-step prepolymer method with polyethylene glycol as the phase change material.
• Characterization using Fourier transform infrared spectroscopy, X-ray diffraction, polarized optical microscopy, and differential scanning calorimetry.
• Evaluation of thermal durability through thermal cycling tests and thermogravimetric analysis.

Main Results:

• Successful synthesis of novel SSPCMs confirmed by FTIR.
• Solid-solid phase transition confirmed by XRD and POM.
• SSPCM samples using hexamethylene diisocyanate (HDI) and COT exhibited the highest phase transition enthalpy (126.5 J/g).
• Outstanding thermal durability demonstrated through thermal cycling and TGA.

Conclusions:

• Novel bio-based SSPCMs were successfully synthesized using castor oil-based hyperbranched polyols.
• The choice of isocyanate and crosslinker significantly impacts phase transition properties.
• The developed SSPCMs show excellent thermal stability and high energy storage potential for TES applications.