All change for composites

A US start up has developed a material modifier which, at tiny concentrations, could increase composite toughness by 100%. Liz Nickels spoke to the founders of MITO Material Solutions about their product.

Last August, MITO Material Solutions, based in Stillwater, Oklahoma, USA, received a US$1.1 million grant to develop hybrid additive dispersions for resin and thermoplastic formulators for composites. The grant came from the US National Science Foundation Small Business Innovation Research grant program (SBIR) and the Oklahoma Center for Advanced Science and Technology (OCAST) program, the company said.

According to MITO Materials, this grant represented an important step in its aim to fully commercialize its technology and grow the company. The MITO GO-Series non-nanotube Hybrid additives, it said, could help create lighter and more durable composite products for automotive, wind energy, aerospace, and transportation, with an 100% increase in toughness and an 80% reduction in mechanical failure risk. The material also offers a thermal resistivity increase of 12-14⁰C.

MITO Materials says that the MITO GO-Series is being targeted initially toward uses that need increased flex and compressive properties such as automotive, sporting goods, and transportation, which have a poor history of stress cracking.

The company was founded and is now led by husband and wife team, Haley Marie Keith, CEO and Kevin Keith, Head of Product and Dr Bhishma Sedai as the head  of research and development and PI. (Figure 1.) The hybrid additive was developed in Oklahoma State University’s Helmerich Research Center in Tulsa by Dr Ranji Vaidyanathan, who is the co-PI.

Scaling up

Over the past year, MITO Materials has scaled up its operations to accommodate commercial sales of its patented technology. ‘Our goal this year is to increase the production of our current product to commercial capacity while developing and launching two new products,’ said Kevin Keith, director of product engineering. ‘Our team is currently seeking corporate partners to work alongside in developing these products for market ready applications.’

MITO Materials’ technology involves chemically processing a hybrid additive by hybridizing graphene oxide and polyoligosilsesquioxanes (POSS) molecules that then disperse reactively in polymer systems at a 0.1%/Wt concentration. (Figure 2.) MITO Materials’ products are non-toxic, safe to handle and are engineered to integrate into common industry manufacturing processes including vacuum infusion, prepregs, hand layup and spray, the company says.

In September 2019 the company was awarded another SBIR grant for US$224,988 to research a bybrid additive material that could double the interlaminar toughness of composite materials used in aerospace, recreation, and automotive industries.

I spoke to Haley and Kevin about the background to the company and their plans for the future.

REINFORCED PLASTICS (RP): What’s the history of the company?

HALEY: It’s quite an interesting story. Kevin and I were both in college at Oklahoma State University, and I had started my MBA and the technology had been discovered and patented there, but at that stage we actually had nothing to do with it. I was working with other science students to look into commercializing it, so I assembled a team. Nobody on my team stayed, but luckily Kevin and I were engaged at the time, and so when I came home and explained the technology to him, we both realised the potential. This was in 2016 and it was 2018 when we moved into this full time.

RP: What stage are you at now?

HALEY: We’ve built the technology, and it’s currently being tested by about 15 different customers in different industry segments, so we’re looking for partners to move it along further and grow the company.

RP: What are the issues with introducing modifiers into composite materials?

KEVIN: They can be expensive, and it can be hard to integrate them into manufacturing processes such as automotive due to a lack of handling capabilities. The GO-Series can improve lightweighting at a lower concentration, which helps mitigate the effects on other mechanical properties. As well as this, lower-end applications such as sporting goods and thermoplastics can use our additive.

RP: How do the modifiers they increase the toughness or the lightweight qualities of the resins?

KEVIN: The graphene is hybridized, so that it disperses more easily, with both chemical and physical bonding points within the polymer, which it increases the adherence between the polymer and the substrate. Because the toughness is increased, some of the part’s weight – up to 35% - can also be shed.

RP: What about the impact on recycling?

KEVIN: That’s something we’re testing at the moment. We’re finding a lot of studies that suggest that injecting graphene into polymers, especially thermoplastics, can extend the recyclability lifetime of thermoplastics. We’re also looking at using our modifiers in recycled materials to improve their quality, which could widen the range of applications. MITO Materials believes that, as the whole composite industry replaces more and more metal parts, especially with thermoplastics and composite materials, it’s important to find a way to reuse them too.

RP: What’s unique about the GO-Series?

HALEY: The product is a true hybrid, so that it has the characteristics of a physical additive such as carbon nanotubes and nanosilica as well as a chemical modifier such as bromide. It can also disperse effectively a very low concentration – instead of requiring 5-15% of loading by weight, MITO only requires a 0.1% concentration by weight, which means that one kilogram of our product will make one metric ton of resin or thermoplastic. (Figure 3.)

RP: What research or what tests still need to be done on using the modifiers with certain materials?

KEVIN:  There are so many different combinations of materials! So, what we’re working on right now is narrowing down what system works best for us, especially with regard to scaling up the process, which we’re planning to do imminently. We’re currently working with a chemical company in Kentucky that does contract manufacturing for a range of companies.

RP: I imagine that to some extent you will be led by the companies you work with.

HALEY: Yes, and we’re currently working with a range of companies, including raw material suppliers, manufacturers who are going to be making our product, chemical resin and thermoplastic producers, and even end-users. In one case, we’re working with a company that wants to replace all of the metal in its engine components with modified thermoplastics to enable the electrification of vehicles.

RP: As the modifiers are introduced during the composite processing stage, do they affect the fiber, or how the fiber and the resin are processed together?

KEVIN: As far as we’ve been able to tell, no. And this is the case with carbon fiber, glass fiber, nylon, and Kevlar. We don’t change the processing method in the formulator, compounder or part manufacturing line. We’ve tested the parameters of different fibers, and we’ve seen no difference between them. If it’s a step that the manufacturer wants us to go through, we’re more than happy to do that, but from what we’ve seen, we don’t see a difference.

RP: Can the modifiers be used in prepregs, and, if so, when are they introduced?

KEVIN: The additive can be introduced at any point. We can integrate it during the prepreg manufacture, in the epoxy as it is applied it to the fabric, or we can add it at the molding stage.

RP: Do you think that there will be an increase in the use of graphene in composites over the next few years?

KEVIN: We believe so. We’ve recently joined The Graphene Council, mainly because of the huge uptake in the consumption of graphene and graphene-based products in the composites industry. However, the research is still fairly new on graphene, so companies are still working out how to best use it. We haven’t had any major issues with integrating it into different polymers, substrates or different fibers. From our conversations with other companies, it seems to be much more promising than carbon nanotubes, and much less toxic.

RP: What do you think the main benefits of graphene will be?

HALEY: Many manufacturers focus on its conductive properties, but I think energy storage has the biggest potential. The main benefit for MITO Materials is its toughness, but its weatherability and corrosion resistance are also important.

RP: Do you know where your biggest market might be?

HALEY: We’re still trying to hone in on that exact answer. Right now, we believe it will be thermoplastics because the industry is moving a little faster than that of thermoset – but we’re working with both types of material.

RP: How do you think the composites industry will develop over the next few years?

HALEY: I think transportation and energy are going to be the two primary movers in the composite space. We’re moving away from the global metals industry and moving further into composites and the ability to reuse and recycle materials. However, ultimately, it will depend on how materials evolve and how we’re able, as a community, to work out how to make composite materials more sustainable.

RP: What’s next for the company?

HALEY: In the next ten years, we’d like to go from being a start-up company to what Gore-Tex became to outdoor weather gear, and what Teflon is to cooking! We want to make every composite material more durable and sustainable.

MITO Materials Solutions;