Hybrid composites made from recycled materials: moisture absorption and thickness swelling behavior

Area of Science:

• Materials Science
• Polymer Science
• Sustainable Materials

Background:

• Developing eco-friendly composite materials is crucial for reducing waste.
• Recycled materials like newspaper fiber and wood flour offer sustainable reinforcement options.
• Polypropylene composites are widely used but can suffer from poor interfacial adhesion and water sensitivity.

Purpose of the Study:

• To investigate the impact of recycled newspaper fiber (RNF) and poplar wood flour (PWF) content on the water absorption and thickness swelling of recycled polypropylene (RPP) composites.
• To evaluate the role of maleated polypropylene (MAPP) as a coupling agent in enhancing the properties of these hybrid composites.
• To understand the relationship between fiber composition, coupling agent concentration, and composite performance.

Main Methods:

• Hybrid composite materials were fabricated using injection molding.
• Recycled newspaper fiber (RNF) and poplar wood flour (PWF) were used as reinforcements.
• Recycled polypropylene (RPP) served as the polymer matrix, with maleated polypropylene (MAPP) as the coupling agent.

Main Results:

• Composites with higher fractions of RNF demonstrated increased water absorption due to the higher holocellulose content in RNF.
• The addition of MAPP significantly improved the interfacial adhesion between the RPP matrix and the natural fibers.
• MAPP effectively reduced both water absorption and thickness swelling of the hybrid composites.

Conclusions:

• The RNF content directly influences the water absorption characteristics of the RPP-based composites.
• MAPP is an effective coupling agent for enhancing the compatibility and performance of RNF/PWF reinforced RPP composites.
• These findings contribute to the development of sustainable composite materials with improved durability for various applications.