Glass fiber (GF)/polypropylene (PP) composite studied by Raman disrelation mapping

Area of Science:

• Materials Science
• Polymer Science
• Spectroscopy

Background:

• Investigating the interface between glass fiber (GF) and polypropylene (PP) is crucial for understanding composite material properties.
• Submolecular-level variations at the GF-PP interface influence the overall performance of the composite.
• Traditional analysis methods may not fully capture the complex interactions at this interface.

Purpose of the Study:

• To apply disrelation mapping to Raman imaging data for the first time.
• To investigate submolecular-level variations at the glass fiber-polypropylene interface.
• To elucidate the role of glass fiber and compatibilizers as nucleating agents in polypropylene.

Main Methods:

• Raman imaging spectroscopy was employed to acquire spectral data.
• Disrelation mapping was utilized to analyze the Raman spectra and generate spatial and spectral information.
• Analysis focused on identifying specific spectral bands associated with molecular structures (e.g., helix bands at 1002 cm⁻¹ and 974 cm⁻¹).

Main Results:

• Disrelation maps provided detailed spatial and spectral insights not accessible from hypercubic data.
• A predominant development of a long helix band (1002 cm⁻¹) was observed at the GF-PP interface, surpassing the short helix band (974 cm⁻¹).
• Increased disrelation intensity was detected both at the surface and within the bulk of the sample.

Conclusions:

• Glass fiber and compatibilizers act as intrinsic nucleating agents for polypropylene.
• This nucleation induces enhanced crystalline structure development in polypropylene.
• The enhanced crystallinity leads to a harder but more brittle polymer system.