Complex Effects of Hemp Fibers and Impact Modifiers in Multiphase Polypropylene Systems

Area of Science:

• Materials Science
• Polymer Science
• Composite Materials

Background:

• Polypropylene (PP) composites offer advantages but struggle to balance stiffness and toughness.
• Developing PP composites with both high stiffness and toughness is a manufacturing challenge.
• Natural fiber composites are increasingly explored for sustainable material applications.

Purpose of the Study:

• To investigate the effects of SEBS and SBS modifiers on PP/hemp fiber composites.
• To tailor mechanical properties of PP composites for electrical vehicle parts.
• To understand the role of maleated polypropylene (MAPP) in modifying composite interfaces.

Main Methods:

• Incorporation of poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) and poly(styrene-b-butadiene-b-styrene) (SBS) into PP/hemp fiber composites.
• Use of maleated polypropylene (MAPP) to control interfacial properties.
• Mechanical testing (Young's modulus, storage modulus, elongation at break, impact strength) and Scanning Electron Microscopy (SEM) analysis.

Main Results:

• SEBS and SBS modifiers exhibited distinct effects on mechanical properties.
• SEBS-containing composites showed greater elongation at break and impact strength.
• SBS-containing composites demonstrated higher Young's and storage moduli.
• SEM analysis revealed better dispersion and smaller particle size for SEBS compared to SBS.

Conclusions:

• SEBS and SBS act as effective impact modifiers, offering different property profiles for PP/hemp fiber composites.
• The choice of modifier (SEBS vs. SBS) allows for tailoring composite properties for specific automotive applications.
• These modified composites show potential as sustainable alternatives to traditional automotive materials.