New science behind algae-based flip-flops
Biodegradable shoes meet commercial standards for products needed to help eradicate tons of plastic waste

Date:
August 6, 2020
Source:
University of California - San Diego
Summary:
Sustainable flip-flops: A team of researchers has formulated
polyurethane foams made from algae oil to meet commercial
specifications for midsole shoes and the foot-bed of flip-flops.



FULL STORY ==========================================================================
As the world's most popular shoe, flip-flops account for a troubling
percentage of plastic waste that ends up in landfills, on seashores and
in our oceans.

Scientists at the University of California San Diego have spent years
working to resolve this problem, and now they have taken a step farther
toward accomplishing this mission.


========================================================================== Sticking with their chemistry, the team of researchers formulated
polyurethane foams, made from algae oil, to meet commercial specifications
for midsole shoes and the foot-bed of flip-flops. The results of their
study are published in Bioresource Technology Reports and describe the
team's successful development of these sustainable, consumer-ready and biodegradable materials.

The research was a collaboration between UC San Diego and startup company Algenesis Materials -- a materials science and technology company. The
project was co-led by graduate student Natasha Gunawan from the labs of professors Michael Burkart (Division of Physical Sciences) and Stephen
Mayfield (Division of Biological Sciences), and by Marissa Tessman from Algenesis. It is the latest in a series of recent research publications
that collectively, according to Burkart, offer a complete solution to
the plastics problem -- at least for polyurethanes.

"The paper shows that we have commercial-quality foams that biodegrade in
the natural environment," said Mayfield. "After hundreds of formulations,
we finally achieved one that met commercial specifications. These foams
are 52 percent biocontent -- eventually we'll get to 100 percent."
In addition to devising the right formulation for the commercial-quality
foams, the researchers worked with Algenesis to not only make the
shoes, but to degrade them as well. Mayfield noted that scientists have
shown that commercial products like polyesters, bioplastics (PLA) and fossil-fuel plastics (PET) can biodegrade, but only in the context of
lab tests or industrial composting.

"We redeveloped polyurethanes with bio-based monomers from scratch
to meet the high material specifications for shoes, while keeping the
chemistry suitable, in theory, so the shoes would be able to biodegrade," Mayfield explained.



========================================================================== Putting their customized foams to the test by immersing them in
traditional compost and soil, the team discovered the materials degraded
after just 16 weeks. During the decomposition period, to account for any toxicity, the scientists, led by UC San Diego's Skip Pomeroy, measured
every molecule shed from the biodegradable materials. They also identified
the organisms that degraded the foams.

"We took the enzymes from the organisms degrading the foams and showed
that we could use them to depolymerize these polyurethane products,
and then identified the intermediate steps that take place in the
process," said Mayfield, adding, "We then showed that we could isolate
the depolymerized products and use those to synthesize new polyurethane monomers, completing a 'bioloop.'" This full recyclability of commercial products is the next step in the scientist's ongoing mission to address
the current production and waste management problems we face with plastics
-- which if not addressed, will result in 96 billion tons of plastic
in landfills or the natural environment by 2050. According to Pomeroy,
this environmentally unfriendly practice began about 60 years ago with
the development of plastics.

"If you could turn back the clock and re-envision how you could make the petroleum polymer industry, would you do it the same today that we did
it years ago? There's a bunch of plastic floating in every ocean on this
planet that suggests we shouldn't have done it that way," noted Pomeroy.

While commercially on track for production, doing so economically
is a matter of scale that the scientists are working out with their manufacturing partners.

"People are coming around on plastic ocean pollution and starting
to demand products that can address what has become an environmental
disaster," said Tom Cooke, president of Algenesis. "We happen to be at the right place at the right time." The team's efforts are also manifested
in the establishment of the Center for Renewable Materials at UC San
Diego. Begun by Burkart, Mayfield, Pomeroy and their co-founders Brian
Palenik (Scripps Institution of Oceanography) and Larissa Podust (Skaggs
School of Pharmacy and Pharmaceutical Sciences), the center focuses on
three major goals: the development of renewable and sustainable monomers
made from algae and other biological sources; their formulation into
polymers for diverse applications, the creation of synthetic biology
platforms for the production of monomers and crosslinking components; and
the development and understanding of biodegradation of renewable polymers.

"The life of material should be proportional to the life of the product,"
said Mayfield. "We don't need material that sits around for 500 years
on a product that you will only use for a year or two."

========================================================================== Story Source: Materials provided by
University_of_California_-_San_Diego. Original written by Cynthia Dillon
and Mario Aguilera. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Natasha R. Gunawan, Marissa Tessman, Ariel C. Schreiman, Ryan
Simkovsky,
Anton A. Samoylov, Nitin K. Neelakantan, Troy A. Bemis, Michael D.

Burkart, Robert S. Pomeroy, Stephen P. Mayfield. Rapid
biodegradation of renewable polyurethane foams with
identification of associated microorganisms and decomposition
products. Bioresource Technology Reports, 2020; 11: 100513 DOI:
10.1016/j.biteb.2020.100513 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200806164657.htm

--- up 3 weeks, 1 day, 1 hour, 55 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)