Interfacial modification on polyhydroxyalkanoates/starch blend by grafting ​in-situ

Area of Science:

• Polymer Science
• Materials Science
• Biomaterials

Background:

• Poor interfacial adhesion between polyhydroxyalkanoates (PHAs) and native starch limits their blend applications.
• Developing effective methods to enhance compatibility in biopolymer blends is crucial for material innovation.

Purpose of the Study:

• To improve the interfacial adhesion between PHAs and native starch through in-situ grafting.
• To characterize the grafting process and evaluate the properties of the resulting PHA/starch blends.

Main Methods:

• In-situ grafting of PHAs onto starch using dicumyl peroxide (DCP) as a free radical initiator.
• Characterization via gel analysis and Fourier transform infrared spectroscopy (FT-IR).
• Evaluation of interfacial adhesion, mechanical properties, and thermal stability using dynamic mechanical analysis (DMA) and decomposition analysis.

Main Results:

• Successful grafting of PHAs onto starch, confirmed by gel analysis and FT-IR.
• Improved interfacial adhesion in PHA/starch/DCP blends, evidenced by plastic deformation and reduced adhesion factor.
• Enhanced thermal stability (higher decomposition active energy) in PHA/starch/DCP blends compared to neat PHAs and physical blends.
• A linear correlation was found between mechanical properties and gel yield.

Conclusions:

• In-situ grafting using DCP is an effective strategy to enhance interfacial adhesion between PHAs and starch.
• The modified PHA/starch blends demonstrate improved thermal stability, making them suitable for broader applications.
• This study presents a cost-effective method for utilizing starch in PHA biopolymer blends.