Page 51 - Plastics News August 2021

TECHNoLoGY

Polymer Enables Tougher Recyclable cereal processing firm Nordgetreide to

Thermoplastics turn professor Kharazipour's idea into
a commercial reality .Stefan Schult,
Managing Director of Nordgetreide,
researchers built their polymer from a which holds an exclusive licence, adds:
cyclic acetal monomer called dioxolane, "Each and every day we pollute our
which is synthesized from potentially Earth with an ever increasing amount
biorenewable formaldehyde and of plastic waste that will be a burden
ethylene glycol feedstocks. Polyacetals on our eco-system for thousands of
are strong candidates for creating years. Our popcorn packaging is a great
recyclable thermoplastics because they sustainable alternative to polystyrene
are stable upward of 300 degrees Celsius, which is derived from petroleum.
but depolymerize at relatively low The plant-based packaging is made
temperatures -- usually below 150 from the inedible by-products of
esearchers from the Cornell degrees Celsius -- in the presence of Cornflakes production and can actually
be composted after use without any
RUniversity have created a tougher an acid catalyst. Using a process called residue." Driven in part by pressure
polymer that can form long chains . The reversible-deactivation cationic ring- from increasingly environmentally-
team of researchers took a middling opening polymerization, the researchers conscious consumers, many companies
monomer and, by using a special catalyst, were able to connect the monomers are changing the way their products
they created a tougher polymer that can into long chains of PDXL that have are packaged to be more sustainable.
form long chains. The polymer can then high molecular weight and high tensile Supermarkets like Tesco and ASDA
be easily depolymerized back to the strength. The resulting thermoplastic in the UK, have been phasing out the
monomer state with an acid catalyst, is strong and flexible enough to be use of unnecessary plastic films for
resulting in a chemically recyclable used for large-scale applications such products such as yogurt pots, greeting
thermoplastic that competes with the as packaging products. This makes it a cards and bed linen. In the US, Walmart
most popular plastics, polyethylene perfect candidate for a circular polymer has stopped using clear plastic in
and polypropylene. The team's paper, economy. doll packaging and is removing the
"Chemically Recyclable Thermoplastics wrapping from some vegetables like
from Reversible-Deactivation Scientists Develops individual peppers, WEF wrote in a
Polymerization of Cyclic Acetals," report.
published Aug. 13 in Science. The co- New Kind Of Packaging
lead authors are former postdoctoral
researcher Brooks Abel and Rachel From Popcorn
Snyder, Ph.D. '21. "Ideally, the perfect
polymer is one that has really high initial cientists have found an extraordinary
stresses and then it undergoes really Smaterial for packaging that can easily
good elongation," said Geoffrey Coates, be reused and is also eco-friendly.A
the Tisch University Professor in the scientist at Gottingen University in
College of Arts and Sciences, and the Germany, Alireza Kharazipour, has
paper's senior author. "The polymers created a new kind of packaging that
you've probably heard of, polyethylene has been developed from popcorn.
and polypropylene, they just have great According to the World Economic
properties. A lot of new polymers don't Forum video, the German professor
compare well with these tried-and- came up with this idea when he went
true ones. Our polymer is right in the to a movie theatre. He realised that
middle of the pack. It has been around popcorn was similar to polystyrene. The
for 60 or 70 years, but no one's been packaging is made by using by-products
able to make really long chains of it from a cornflake factory.The Gottingen
and get really good properties." The University has partnered with German

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