Page 55 - Plastics News January 2022

TECHNoLoGY

Bio-Based Polymers Can Be Transformed Into Scientists Develop

Fertilizer Bacteria-Killing Food

Packaging Material

esearchers from Singapore
Rand the US have developed a
biodegradable packaging material that
can kill microbes harmful to humans.
The sustainable material is created by
scientists from Nanyang Technological
University (NTU) Singapore and
Harvard T.H. Chan School of Public
Health, US. This packaging material
is made from a kind of corn protein
known as zein, starch and other
biopolymers that are then infused

ioplastics can be chemically recycled poly (isosorbide carbonate), or "PIC," with natural antimicrobial compounds
Binto nitrogen-rich fertilizers in a type of bio-based polycarbonate such as oil from thyme, and citric
a facile and environmentally friendly that has garnered much attention as acid. During lab experiments, the
way, says a report. However, the rise of an alternative to petroleum-based fibres, on being exposed to increased
these synthetic polymers, which form polycarbonates. PIC is produced using a humidity or enzymes from harmful
the basis of plastics, has contributed non-toxic material derived from glucose bacteria, released small amount of the
to many serious environmental issues. called isosorbide (ISB) as a monomer. antimicrobial compounds that in turn
The worst of these is the excessive The interesting part is that the carbonate kill bacteria such as coli and Listeria,
use of petrochemical compounds and links that join the ISB units can be as well as fungi. The material has the
the disposal of non-biodegradable severed using ammonia (NH3) in a
materials without recycling; only 14% process known as 'ammonolysis'. The
of all plastic waste is recycled, which process produces urea, a nitrogen-
hardly puts a dent in the problem. rich molecule that is widely used as a
To solve the plastic conundrum, we fertilizer. While this chemical reaction
need to develop "circular" systems, was no secret to science, few studies on
in which the source materials used to polymer degradation have focused on
produce the plastics come full circle the potential uses of all the degradation
after disposal and recycling. At Tokyo products instead of only the monomers.
Institute of Technology, a team of First, the scientists investigated how
scientists led by Assistant Professor well the complete ammonolysis of
Daisuke Aoki and Professor Hideyuki PIC could be conducted in water at
Otsuka is pioneering a novel concept. mild conditions (30°C and atmospheric potential to be used for storing food
In their new environmentally friendly pressure). The rationale behind this items such as raw meat, fish, fruit,
process, plastics produced using decision was to avoid the use of organic vegetables and ready-to-eat meals
biomass (bioplastics) are chemically solvents and excessive amounts of because the compounds can fight
recycled back into fertilizers. This study energy. The team carefully analyzed all bacteria growing on the surface of the
will be published in Green Chemistry, the reaction products through various packaging as well as on the food itself.
a journal of the Royal Society of means, including nuclear magnetic The scientists believe the advanced
Chemistry focusing on innovative resonance spectroscopy, the Fourier packaging material is expected to
research on sustainable and eco-friendly transform infrared spectroscopy, and extend the shelf-life of fresh fruit by
technologies. The team focused on gel permeation chromatography. two to three days.

54 PLASTICS NEWS JANUARY 2022 55 PLASTICS NEWS JANUARY 2022