Connora Technologies makes epoxy truly recyclable

Recyclamine hardener turns thermoset to thermoplastic and offers ability to design composites to be recyclable from the start.

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Connora Technologies' Recyclamine hardener enables composites to be separated back into resin and fibers for reuse with the epoxy resin converted into a recyclable thermoplastic.

I first saw Recyclamine over a year ago in an Italian composites magazine and put it on my Blogs To-Do list. Then I saw Adesso and their Cleavamine product. Two producers of hardeners enabling epoxies to be recycled like thermoplastics? Well, yes and no. I interviewed Connora Technologies’ CEO, Rey Banatao. Here is the story.

Rey has a degree in Biochemistry from the University of California, Berkeley and a PhD in Computational Biology. He was also a postdoctoral fellow at the California Nanosystems Institute at UCLA. He co-founded Entropy Resins (Hayward, Calif.) with his brother Desi, who is also a Berkeley grad, with a Masters in Material Science and Engineering. Their goal was to develop renewable materials for performance composites. This is exactly what they have achieved over the past 6 to 7 years through Entropy’s Super Sap epoxy resins, which reduce greenhouse gas emissions by 50 percent vs. petroleum based epoxies and are made from plant-based co-products or waste from established industrial processes, so they don’t displace food crops.

Expanding on Entropy’s bio-based resins, Desi also co-founded Lingrove (San Francisco, Calif.) with Joe Luttwak of Blackbird Guitars (San Francisco, Calif.) which offers the unique expertise they have developed in prepregging and molding with biobased fabrics. Lingrove supplies natural flax fiber reinforcements and prepregs, as well as hybrids with glass and carbon fibers to achieve exceptional performance. A bicycle frame on display at CAMX 2014 (Oct. 13-16, Orlando, Fla.) has a certified 75 percent biobased content thanks to use of Lingrove's ‘Ekoa’ prepregs. As Luttwak played Blackbird’s Clara concert ukulele for me, he noted that sales of these instruments into Hawaii have picked up because they offer moisture stability for open-air performers vs. traditional tropical hardwoods, which are becoming increasingly rare and expensive. Ekoa is not just a sustainable alternative, it’s achieving a marketable advantage. Let me say that again, Lingrove can tailor a composite to look like wood and sound like wood but offer advantages in dynamic range of sound — i.e. vibration — and environmental durability not to mention lightweight. (Link to article on new El Capitan guitar.)

Back to Rey and Desi, their work with Lingrove and Entropy to certify biocontent and the carbon footprint of the composite materials and processes, including complete life cycle assessments, is now part of a growing trend in consumer goods worldwide.

It’s at this point where Connora’s founder and chief technical officer, Stefan Pastine, enters. While doing post-doctoral research at UC Berkeley under a professor who pioneered photoresist chemistry (now fundamental to micro chip patterning processes), Pastine thought to apply the concept of “designed in cleavage points” to epoxies. He then developed the chemistry to work in polyamine curing agents. Rey Banatao explains, “If you engineer it right, you can break apart the crosslinks and can get back thermoplastic molecules which allows the resin to be reclaimed…or anything bound by the resin as well.” In discussing the benefits vs. other recycling methods, such as pyrolysis (which burns away the plastic matrix), their chemical approach can maintain the reclaimed fiber’s virgin properties and length, and returns the matrix as an epoxy thermoplastic.

Pastine then traveled to China to work on nanotechnology for Adesso Advanced Materials (Wu Xi, Jiangsu Province, China). When the nanotechnology did not develop as planned, Pastine shared his recyclable epoxy technology and formed an agreement with CEO Bo Liang that Adesso would help with manufacturing and marketing of the new materials, but no exclusivity was established.

Pastine then returned to the U.S. and founded Connora Technologies. Although the original technology patents are shared by Connora and Adesso, they represent just the beggining of the journey to making the technology a commercial reality.  Since 2012, Pastine has developed and patented a second generation Recyclamine technology, exclusive to Connora.  Adesso is licensed to sell this and the two issued a joint press release in May, explaining their relationship and cooperation. “They are a good partner in a large market,” says Banatao, “and share our excitement about recyclable thermosets. As Connora’s technology becomes commercialized, we see Adesso as a good distribution partner to help provide access to Chinese markets, as well to provide an epicenter for recycling."  Banatao adds that Connora is also working with globally positioned chemical companies, with the goal of increasing both industrial-scale supply and applications for truly recyclable epoxy resins and composites.

When asked about applications, Banatao notes that his background via Entropy has been mostly in consumer facing products, especially sporting goods (e.g. surf, skate, and standup paddle boards, etc.). This year Burton (Burlington, Vt.) is introducing a line of snowboards using Super Sap resins. “But we’ve always had an eye out for industrial applications,” he observes. Connora’s focus is really targeting these large markets, where composites are made in high volumes and generate a lot of waste. “We definitely saw Recyclamine’s potential and served as both investor and incubator for Connora,” Banatao explains. “As the effort grew, it made sense for me to take on the role of CEO. While we are working on setting up manufacturing partnerships with large chemical companies, we are also expanding our own pilot manufacturing and R&D facilities here in Hayward.”

But can Connora really produce Recyclamine on an industrial scale? “All of the chemistry we developed was unprecedented, so at first, we had to determine what was even possible…what Recyclamines could be made from, and what properties they had.   Then, we had to go through several process iterations,” Banatao concedes. “But now we have made it more affordable and have also developed renewable feedstocks. We’ve also tried to get away from harmful or explosive chemistries, so our manufacturing process is safer and does not require highly specialized infrastructure. We’ve developed a whole new platform for how to make amines. This alone should be of value to the chemical industry as a whole.”

Banatao is very passionate about Connora’s ability to revolutionize composites, “Why don’t we start reengineering tomorrow’s composites so that it takes less energy to reuse them? It’s great to use recycled fibers, but what can we do to make that easier and design composites to be recyclable from the start? We (the industry) did this for thermoplastics. Why not thermosets? ” He also points out that a new process for handling composite waste, recycling, and then reusing the reclaimed materials will need development. While he and the Connora team know that reclaiming carbon fiber is currently the main economic driver of composite recycling, they are also looking for good applications of the recycled epoxy thermoplastic.

Okay, but are the original epoxies easy to work with? “Anything that uses an epoxy can use the technology," says Banatao. "We have a room temperature system that is easy to infuse with and we’ve also used it in compression molding. We also have a latent cure system for prepreg, filament winding, or pultrusion and are developing a version for high pressure resin transfer molding (HP-RTM) for the automotive industry.”

The future for this technology seems almost too large to grasp, really, if you think about Connora’s headway toward a two-minute cure cycle for the HP-RTM system and higher Tg systems which could be used in circuit boards. The Banataos have dedicated most of their careers to making composites more sustainable and environmentally friendly. With inventor Stefan Pastine and Connora Technologies, the potential now exists to change the industry on a massive scale. The question is, will the industry exploit this potential and increase composites’ competitive position vs. plastics, metal and wood?