# Effect of Carbon-Based Modifications of Polydicyclopentadiene Resin on Tribological and Mechanical Properties

## TL;DR

This paper studies how adding different carbon materials to a polymer resin affects its strength and friction properties.

## Contribution

The study introduces a comparison of various carbon-based fillers in PDCPD resin for self-lubricating composites.

## Key findings

- Carbon fibers and graphite-filled PDCPD achieved ~50 MPa tensile strength.
- Graphite variants reduced friction three-fold in tribological tests.
- Carbon nanotubes decreased tensile strength by half compared to pure resin.

## Abstract

Self-lubricating polymer composites based on polydicyclopentadiene (PDCPD) were reinforced with carbon nanomaterials to evaluate the effect of filler type and loading on their mechanical and tribological performance. Four carbon forms were introduced: carbon nanotubes (0.3 and 0.5 wt.%), carbon fibers (5 and 10 wt.%), flake graphite (5 and 10 wt.%) and dusty graphite (5 and 10 wt.%). Tensile tests showed that carbon fibers—and graphite-filled matrices reached ~50 MPa tensile strength, while the addition of carbon nanotubes resulted in a reduction in strength by half compared to the pure resin, indicating poor compatibility of carbon nanotubes with the matrix. The highest compressive strength, ~90 MPa, was obtained for PDCPD containing 5 wt.% carbon fibers. Tribological behavior was evaluated in a pin-on-disk configuration under dry sliding. All fillers lowered the coefficient of friction; the most pronounced, three-fold reduction was achieved with both graphite variants. The combined high load-bearing capacity and greatly reduced friction of the graphite and carbon fibers modified systems highlight their potential as self-lubricating bearing materials capable of replacing conventional metal or oil-lubricated components.