Modification of Rigid Polyurethane Foams with Straw Additive: Influence of Chemical Treatment and Content on...

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Materials

Background:

• Rigid polyurethane foams (PUFs) are widely used but often rely on petroleum-based components.
• Developing sustainable and cost-effective fillers is crucial for eco-friendly PUF production.
• Cellulose-based materials offer potential as renewable fillers, but their compatibility with polymer matrices needs optimization.

Purpose of the Study:

• To synthesize rigid polyurethane foams modified with cellulose from straw.
• To investigate the effects of unmodified, silanized, and silica-enhanced silanized straw on foam properties.
• To determine the optimal loading of straw-based modifiers for improved functional characteristics.

Main Methods:

• Synthesis of rigid polyurethane foams with varying weight percentages (0.5, 1, 3 wt.%) of straw modifiers.
• Characterization of reaction kinetics and functional properties of the modified foams.
• Analysis of thermal stability, mechanical strength, cell morphology, density, and water resistance.

Main Results:

• Silanization improved thermal stability and interfacial compatibility between straw and polyurethane.
• Silica addition further enhanced foam porosity and surface activity.
• Optimal properties were achieved at low loadings: 0.5 wt.% for mechanical strength and 1 wt.% for uniform cell morphology and density.
• Higher straw content led to increased porosity, reduced strength, and decreased water resistance.

Conclusions:

• Modified straw acts as an effective biofiller for enhancing rigid polyurethane foams.
• Low loadings of modified straw significantly improve mechanical, structural, and water-resistant properties.
• This approach presents a sustainable and cost-effective method for producing eco-friendly polyurethane foams.