# Additive Manufacturing of Thermoset Elastomer–Thermoplastic Composites Using Dual-Extrusion Printing

## TL;DR

This paper explores 3D printing of thermoset elastomer-thermoplastic composites, showing how material compatibility and process parameters affect adhesion and performance.

## Contribution

A custom printer and analysis of interfacial bonding mechanisms enable multi-material 3D printing with improved adhesion in demanding environments.

## Key findings

- Interfacial bonding is enhanced by matching solubility parameters and using amorphous thermoplastics.
- Curing at lower temperatures for longer durations improves adhesion between materials.
- Elemental analysis shows migration of rubber components to the thermoplastic surface.

## Abstract

This work investigated the 3D printing of fully compounded thermoset elastomers using a custom-designed printer capable of processing both thermoplastics and elastomers containing fillers and specific cure packages. The adhesion strength between selected thermoset elastomers and thermoplastic combinations was studied, and the influence of key process parameters on adhesion was evaluated. The results showed that interfacial bonding was favored by the proximity of solubility parameters, the amorphous morphology of the thermoplastic, and increased chain mobility at the processing temperature. Rubber processing parameters significantly influenced adhesion, showing that curing at a lower temperature for a longer duration yielded better results than shorter, higher-temperature cures. Elemental analysis revealed the presence of rubber-specific components on the thermoplastic surface, suggesting interfacial migration. These findings contribute to advancing multi-material 3D printing by enabling the integration of rubber-like materials with thermoplastics, expanding opportunities for applications in high-temperature and chemically demanding environments.