New Coating Mimics Polymer from Mussels

MONDAY, OCTOBER 3, 2022


A coating from specialty materials company Mussel Polymers, Inc., has recently been used to strengthen carbon and aramid fibers, allowing for stronger, more lightweight materials.

Using poly catechol styrene (PCS), which is a polymer that mimics the adhesive used by mussels to adhere to underwater substrates, the company reports that the latest application can increase the strength and impact energy of fiber reinforced materials.

About PCS Coatings

Launched in 2019, MPI develops adhesive solutions building from its base technology, licensed from Purdue University, at the Ben Franklin Technology Facility in Bethlehem, Pennsylvania. The company commercializes products based on its biomimetic PCS, ranging from dental adhesives to defense ships and vehicles.

While mussel peptides cure quickly underwater, they are complex and prohibitively expensive. To resolve this, MPI developed the synthetic version through biomimetics to ensure commercial viability.

John Wilker, inventor of the PCS system and Professor of Chemistry at Purdue University with the backing of the Office of Naval Research, figured out a way to copy the function of the mussel glue in a simpler highly effective molecule.

According to the company’s website, PCS is nontoxic, binds underwater and is environmentally friendly. The polymer is reportedly 300% stronger when compared to other commercial underwater adhesives.

It can attach to a wide range of materials including, but not limited to wood, steel, aluminum, styrene, acrylic, urethane, epoxy, polyester, TPU and TPO.

PCS priming reportedly makes other adhesives stronger and can bond to wet surfaces. It also can be combined with any chemistry with a long shelf life.

Latest Achievement

At the end of last month, MPI announced that it has successfully coated carbon and aramid fibers with PCS, marking a step forward in producing lighter, stronger fiber reinforced composites.

According to the press release, the application is likely to significantly increase the strength and impact energy of fiber reinforced materials. Additionally, it is anticipated to improve the use of coatings and adhesives with carbon fiber parts and materials.

“The MPI team successfully coated carbon and aramid fibers with PCS using a simple one-step, room temperature process. These coated fibers were examined under the scanning electron microscope at Lehigh University,” said Jason Stieg, Chief Commercial Officer of MPI.

“The resulting images were striking and showed complete coverage of the fibers. The ability of our polymer to bond to these surfaces has applicability in both advanced composite materials and the assembly and coating of carbon fiber parts.”

Carbon and aramid fibers are difficult to bond with because they are smooth and chemically inert. MPI explains that previous coating work with polydopamine (PDA), a catechol containing research agent like PCS, showed that the shear strength of a single coated fiber pulled from its matrix increased over 200% compared to that of a raw fiber. 

The flexible strength and impact energy of reinforced composites also made with the coated fibers reportedly increased over 200%.

“We are excited to have expanded the uses of our Poly(catechol-styrene). With this development allowing for stronger, lightweight materials, we will expand our partnerships with new materials and products companies,” said George Boyajian, CEO of MPI.

“The simplicity of this coating process may accelerate its adoption and allow for safer and more environmentally sound materials.”

PCS is reportedly the first commercially available catechol compound used to coat carbon fibers, among other uses. The company reports that it is currently in discussions to jointly develop new composite materials with its PCS.

Other Mussel Research

At the beginning of this year, researchers at the University of Toronto looked at the adhesion of mussels on surfaces to potentially create new antifouling coatings for infrastructure and medical adhesives. The study, led by professor Eli Sone, was published in Scientific Reports.

The research team has reportedly been studying zebra and quagga mussels for years at the university’s material science and engineering research lab. These species are native to lakes and rivers in southern Russia and Ukraine, and likely made their way to the Great Lakes in North America in the 80s on ships from Europe.

“One of the challenges is how small these mussels are compared to other species,” said Bryan James, who worked on the project as part of his undergraduate thesis, and is now a postdoctoral scholar at the Woods Hole Oceanographic Institution in Woods Hole, Massachusetts.

“The threads they use to attach themselves to surfaces are only a few millimeters long, and as thin as a human hair. You can’t put them in a traditional apparatus for testing tensile strength.”

To solve this problem, the team utilized a pair of fine-tipped, self-closing tweezers, a digital camera and a force gauge to measure how much force was required to break the protein-based glue secreted by the mussels. The mussels were collected from the wild and placed on glass, PVC and PDMS substrates to reattach.

Quagga mussels reportedly showed a significantly lower attachment rate on PDMS compared to glass and PVC, while the zebra mussels showed a consistent attachment rate across all three substrates.

Research found that overall the mussels adhered more strongly to glass than they did to plastics. According to the University of Toronto, researchers expected this since glass is inorganic and hydrophilic, similar to the rocks that the mussels use as substrates in nature, while PDMS repels water and is often coated on boat hulls to prevent biofouling.

Using electron microscopy, researchers scanned the glue left behind on the surfaces after the threads were detached. The adhesive residue is known as a footprint, so the newly identified failure was named a “footprint failure” in the study. The occurrence of this failure indicates an incomplete detachment, demonstrating a strong adhesion from the mussels.

Their research is ongoing, testing on new types of surfaces to prevent fouling of critical infrastructure, as well as investigating the differences in adhesion between freshwater and marine mussels.

In addition to creating surfaces that would be harder for mussels to stick to, the research team is analyzing the glues produced by the two mussel species, with a goal of potentially mimicking them in biomedical adhesives.

   

Tagged categories: Adhesion; Adhesive; Asia Pacific; Biomimicry; Coating chemistry; Coating Materials; Coatings; Coatings Technology; Coatings technology; EMEA (Europe, Middle East and Africa); Latin America; Marine Coatings; North America; Polymers; Program/Project Management; Research and development; Z-Continents

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