Issue 04/2018

From Science & Research
Bioplastic made of cactus
(Photo: EFE)
With the juice of nopal, a plant of the cactus family and
basic ingredient in Mexican cuisine, a Mexican researcher
has created a natural biodegradable plastic
that can reduce pollution.
Sandra Pascoe, from the Universidad del Valle de Atemajac
(Univa) in Guadalajara, western Mexico, developed this plastic
after several experiments with this cactus often used in salads
and traditional Mexican stews.
At first, she experimented with dried pieces of nopal, which
she mixed with additives, but the process was slow and the
physical and chemical characteristics changed a lot. “The
material oxidized quickly”, she told the Mexican news agency
EFE.
Sandra then began to use the juice of the species’opuntia
ficus indica’, the most common among the nopal trees and
widely used as a vegetable. Later she took the so-called
opuntia megacantha, which is famous for its fruit called tuna,
very juicy but covered all over with thorns.
“Basically, the plastic is made from the sugars in the nopal
juice, the monosaccharides and polysaccharides it contains,”
the researcher explained.
Sandra pointed out that the cactus has a very viscous
consistency that comes from these sugars, pectin and organic
acids and “that viscosity is what we are taking advantage of so
that a solid material can be produced”, she said.
In her lab at the Department of Exact Sciences and
Engineering, Pascoe glycerol, natural waxes, proteins and
colorants with the juice after it has been strained to remove its
fibers, creating a formula that is then dried on a hot plate to
produce thin sheets of plastic.
This process was registered with the Mexican Institute
of Intellectual Property (IMPI) in 2014 and the development
became possible with funding from the National Council of
Science and Technology (Conacyt) of Mexico.
The researcher told EFE that with the support of the
campus of Biological and Agricultural Sciences of the
University of Guadalajara, she is in the process of investigating
the degradation characteristics of this plastic, i.e. in what
conditions and how long it takes to decompose in a natural
environment.
“We have done very simple degradation tests in the
laboratory. We have put it for example in water and we found
that it does disintegrate. However, we still need to do a
chemical test to see if the material has really been completely
disintegrated. We have also done tests on moistened compost
soil and the material is also disintegrated”, she added.
Sandra said that in addition to shopping bags, the nopal
juice plastic could be used for applications such as cosmetic
containers, imitation jewelry and toys.
Tests are currently being conducted to establish how much
weight the plastic can bear which will help determine what
other products it could be used for.
She explained that projects have already been done at
student level to generate prototypes “very simple and it is clear
that there is potential to do a lot more with this material”.
At the moment thermal properties and the density of the
plastic are being determined to learn how much weight it
can resist in case of being transformed into bags and other
products.
The next step on the path towards commercialization will be
to make or buy a machine that can produce prototypes of the
plastic bags in order to market them to businesses.
The innovation is in the process of being patented. Once this is
granted by the IMPI, it will be possible to generate agreements
to transfer the technology to interested companies, Sandra
Pascoe concluded. MT Source: EFE tinyurl.com/cactusplastic
(Photo: Kerstin Neumeister)
bioplastics MAGAZINE [04/18] Vol. 13 43