Boydston Research Group
UW-Madison Department of Chemistry

Access to Functionalized Materials by Metal-Free Ring-Opening Metathesis Polymerization of Active Esters and Divergent Postpolymerization Modification

Posted on

ACS Macro Lett. 2024, 13, 2, 144–150

Metal-free ring-opening metathesis polymerization (MF-ROMP) is an emerging polymerization strategy that provides access to ROMP materials by using organic initiators and photoredox catalysts. Unlike metal-mediated ROMP, MF-ROMP is not highly tolerant toward functionalized monomers. Herein, we report that pentafluorophenyl esters are polymerizable under MF-ROMP conditions to produce homopolymers, statistical copolymers, and block copolymers. Amine coupling agents were then used to install a range of functional groups via acyl substitution including alkynes, amino acid derivatives, fluorophores, and redox active moieties. Overall, these findings provide a framework to prepare functionalized ROMP polymers without the risk of metal contamination.

Block copolymer additives for toughening 3D printable epoxy resin

Posted on

Giant, Volume 17, March 2024, 100204

We explore the potential for using a brush-coil triblock copolymer to enhance the mechanical properties of epoxy resin for 3D printing applications. Epoxy resins are widely used in structural material and adhesive and have great potential for 3D printing. However, the highly brittle nature of epoxy resins requires the use of large concentrations of toughening agents that pose significant challenges in meeting rheological requirements of 3D printing. We report a reactive brush-coil block copolymer with three distinct blocks that can phase separate and chemically crosslink with the base epoxy resin to form spherical aggregates. Detailed scanning electron microscopy imaging shows that these aggregates can arrest and deflect cracks during propagation and can synergistically strengthen (∼ 1.5×) and toughen (∼ 2×) the epoxy resin with even 1 wt% of the BCP additive to the base resin. Importantly, both the modulus and the glass transition temperatures are preserved. Direct ink writing (DIW) and digital light processing (DLP) 3D printing of the modified resins also shows the same strengthening and toughening effects seen in mold-cast samples, demonstrating its compatibility with 3D printing processes. These findings suggest that brush-coil triblock copolymers additives at very low concentrations can synergistically improve the mechanical properties of epoxy resin for 3D printed parts.

Flow Optimization of Photoredox-Mediated Metal-Free Ring-Opening Metathesis Polymerization

Posted on

ACS Macro Lett. 2023, 12, 11, 1479–1485

Photoredox-mediated metal-free ring-opening metathesis polymerization (MF-ROMP) is a convenient metal-free method to produce a variety of ROMP polymers. Transitioning MF-ROMP from a batch to a continuous flow process has yet to be demonstrated and could potentially benefit the production efficiency, safety, and modularity of reaction conditions. We designed and evaluated continuous flow and droplet flow setups and compared the results for MF-ROMP across a short series of common monomers. By using the droplet flow reactor setup, we achieved flow conversions comparable to that of batch and circumvented issues with diffusion-limited mixing and air exposure.

Congrats to Dr. Schilling on earning his PhD!

Posted on

Congrats to Dr. Cody Schilling on defending his PhD dissertation, “Towards Chemical Length-Scale Control in Additive Manufacturing: Innovations in Polymer Material Design and Technology!” Dr. Schilling will continue his scientific career at the Forest Products …

Join the Boydston Group!

Posted on

The Boydston group is recruiting from the Fall 2023 UW-Madison Chemistry Graduate Student cohort! Learn more about our lab’s work with polymer synthesis, photoredox ROMP, mechanochemistry, and 3D printing by joining us for:

Group meetings: 3:00-5:00pm on Mondays in 2401
Literature group meetings: 3:00-4:30pm, biweekly Thursdays starting 9/14 in 2401
You can also get to know everyone by joining us for social events such as:

Bowling at the Sett on Wednesday 9/20, 6pm at Union South
Pumpkin Carving on Wednesday 10/25, 6pm in Union South (room TBD, you’re welcome to wear a Halloween costume)
Game Night on Wednesday 11/15, 6pm in Union South (room TBD)
Please RSVP to social events or send questions to Sarah (sgfinnegan@wisc.edu).

Congrats to Dr. Tritt on earning her PhD!

Posted on

Congrats to Dr. Rachel Tritt on defending her PhD dissertation, “Improving Control and Functionality of Photoredox-Mediated Metal-Free Ring-Opening Metathesis Polymerization!” Dr. Tritt will continue her scientific career at Tolmar Pharmaceuticals, Inc in Colorado. We are …