Monomer diffusion into static and evolving polymer networks during frontal photopolymerisation

Matthew G. Hennessy, Alessandra Vitale, Omar K. Matar, João T. Cabral*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

10 Citations (Scopus)

Abstract

Frontal photopolymerisation (FPP) is a directional solidification process that converts monomer-rich liquid into crosslinked polymer solid by light exposure and finds applications ranging from lithography to 3D printing. Inherent to this process is the creation of an evolving polymer network that is exposed to a monomer bath. A combined theoretical and experimental investigation is performed to determine the conditions under which monomer from this bath can diffuse into the propagating polymer network and cause it to swell. First, the growth and swelling processes are decoupled by immersing pre-made polymer networks into monomer baths held at various temperatures. The experimental measurements of the network thickness are found to be in good agreement with theoretical predictions obtained from a nonlinear poroelastic model. FPP propagation experiments are then carried out under conditions that lead to swelling. Unexpectedly, for a fixed exposure time, swelling is found to increase with incident light intensity. The experimental data is well described by a novel FPP model accounting for mass transport and the mechanical response of the polymer network, providing key insights into how monomer diffusion affects the conversion profile of the polymer solid and the stresses that are generated during its growth. The predictive capability of the model will enable the fabrication of gradient materials with tuned mechanical properties and controlled stress development.

Original languageEnglish
Pages (from-to)9199-9210
Number of pages12
JournalSoft Matter
Volume13
Issue number48
DOIs
Publication statusPublished - 2017

Bibliographical note

Funding Information:
This research was supported by the Engineering and Physical Sciences Research Council (EPSRC) Manufacturing with Light Grant EP/L022176/1. MH has been partially funded by the CERCA Programme of the Generalitat de Catalunya.

Publisher Copyright:
© 2017 The Royal Society of Chemistry.

Fingerprint

Dive into the research topics of 'Monomer diffusion into static and evolving polymer networks during frontal photopolymerisation'. Together they form a unique fingerprint.

Cite this