Polyolefin blends with co-continuous architectures enabled by dynamic covalent crosslinking
- Eliza K. Neidhart
- Stephanie M. Ribet
- Taehyun A. Lee
- Logan Kearney
- Karen. C. Bustillo
- Eric A. Dailing
- Mutian Hua
- Colin Ophus
- Sophia N. Fricke
- Ah-Young Song
- Jeffrey A. Reimer
- Erik J. Alexanian
- Joanna M. Atkin
- Brett A. Helms
- Frank A. Leibfarth
2026-05-15
Blending polymers produces brittle materials due to macrophase separation and poor interfacial adhesion, which is exemplified by mixtures of polyolefins. This presents a formidable challenge for the mechanical recycling of mixed plastic waste. Here, we demonstrate that dynamic covalent crosslinking of immiscible polyolefin blends creates macrophase separated co-continuous architectures, yet they display excellent mechanical properties, which challenges the conventional wisdom regarding morphology-property relationships in polymer blend compatibilization. We find that the position and orientation of dynamic crosslinks and their influence on crystallinity are key to understanding the structure-morphology-property relationships. In particular, high-resolution microscopy imaging reveals alignment of crystallite planes with strong orientational preference, particularly at polymer-polymer interfaces, which contribute to material performance. We further demonstrate that changes in crosslinker density and valency allow the properties of binary and ternary polyolefin blends to be tuned in a modular fashion.