# Novel Low-Crystallinity Polyetheretherketone Copolymers for 3D Printing

## TL;DR

This paper introduces new PEEK copolymers with adjusted crystallinity for better 3D printing performance and material stability.

## Contribution

The study presents novel PEEK copolymers with tailored DCDPS content for improved FDM 3D printing.

## Key findings

- Increasing DCDPS content lowers melting and crystallization temperatures while raising the glass transition temperature.
- Copolymers with 5–20% DCDPS enable stable FDM printing without deformation or delamination.
- At 15% DCDPS, polymer chain rigidity compensates for reduced mechanical properties.

## Abstract

To improve the quality of additive manufacturing of PEEK parts, copolymers with varying 4,4′-dichlorodiphenylsulfone (DCDPS) contents were synthesized. A study of the thermophysical properties of the resulting copolymers revealed that increasing the DCDPS content leads to lower melting temperatures, crystallization temperatures, and degree of crystallinity, while simultaneously increasing the glass transition temperature. It was found that structural amorphization leads to a predictable decrease in the strength and elastic modulus of both cast and printed samples. However, at a DCDPS concentration of 15%, the decrease in mechanical properties is offset by an increase in polymer chain rigidity. The practical result of this study was the successful adaptation of the material to FDM printing: copolymers with DCDPS contents in the range of 5–20% ensured stable molding without deformation or delamination, demonstrating an optimal balance between processability and performance.