Preparation of Polyimide/MWCNT Nanocomposites via Solid State Shearing Pulverization (S3P) Processing

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Polyimide (PI) nanocomposites offer advanced material properties.
• Achieving homogeneous dispersion of multiwall carbon nanotubes (MWCNTs) in PI matrices is challenging.
• Existing methods often result in agglomeration, limiting property enhancements.

Purpose of the Study:

• To develop an effective method for preparing well-dispersed PI/MWCNT nanocomposite films.
• To investigate the impact of homogeneous MWCNT dispersion on the mechanical and thermal properties of PI.
• To introduce a novel solid state shearing pulverization (S3P) approach for polymer composite fabrication.

Main Methods:

• Synthesis of poly(amic acid) (PAA) precursor from ODA and PMDA.
• Mixing PAA powder with BTDA and acid-functionalized MWCNTs (acid-MWCNTs) using the S3P technique.
• Thermal imidization of the mixture to form PI/MWCNT nanocomposite films.

Main Results:

• Homogeneous dispersion of acid-MWCNTs within the PI matrix was achieved.
• Tensile strength of PI was enhanced by 74% with 5.0 wt% acid-MWCNT loading.
• Glass transition temperature (Tg) of PI increased from 303°C to 341°C due to strong interfacial bonding.

Conclusions:

• The S3P approach is a viable and novel method for creating polymer composites with controlled particle dispersion.
• Enhanced mechanical and thermal properties of PI/MWCNT nanocomposites were demonstrated.
• The strong interfacial interaction between PI and acid-MWCNTs is crucial for property improvements.