Carbon-Material-Modified Polyester Nonwoven Composites with Enhanced Mechanical, Electrical, and Thermal Properties

Area of Science:

• Materials Science and Engineering
• Polymer Composites
• Nanotechnology

Background:

• Polyester (PET) nonwoven composites are explored for advanced applications.
• Incorporating conductive fillers like carbon nanotubes (CNTs) and graphene flakes (GFs) can impart multifunctional properties.
• Understanding the influence of filler geometry (1D CNTs vs. 2D GFs) on composite performance is crucial.

Purpose of the Study:

• To investigate how CNT and GF geometry and loading affect conductive network formation in polyurethane (PU)/PET nonwoven composites.
• To analyze the impact of these fillers on anisotropic mechanical behavior and thermal response.
• To directly compare the performance of CNTs and GFs within the same matrix for multifunctional applications.

Main Methods:

• One-sided impregnation of PET nonwovens with PU binder and subsequent addition of CNTs or GFs.
• Characterization using Scanning Electron Microscopy (SEM) to observe filler distribution and morphology.
• Mechanical testing (tensile strength), electrical conductivity measurements, and thermal conductivity analysis.
• Infrared thermal imaging to assess heating and heat dissipation characteristics.

Main Results:

• GFs formed sheet-like coatings and filled pores, while CNTs showed localized aggregation.
• Composites exhibited anisotropic tensile behavior, with higher strength in the longitudinal direction.
• Graphene flake composites (e.g., G4) showed higher tensile strength (13.01 MPa) compared to carbon nanotube composites (e.g., C5, 11.35 MPa).
• Both electrical and thermal conductivities increased with filler content; GFs generally yielded higher conductivity.
• Electrical conductivity reached 0.05893 S/cm for G6 and 0.02100 S/cm for C6.
• Thermal conductivity increased from 0.1793 to 0.2537 W/(m·K) for GF composites and 0.1163 to 0.1923 W/(m·K) for CNT composites.
• Infrared imaging confirmed faster heating and slower heat dissipation in modified composites.

Conclusions:

• Filler morphology significantly influences the properties of PU/PET nonwoven composites.
• Graphene flakes offer superior mechanical reinforcement and thermal/electrical conductivity compared to CNTs in this system.
• These findings support the development of multifunctional nonwoven composites for smart textiles and thermal management applications.