Page 174 - CW E-Magazine (25-2-2025)

Free to Die

Why not consider cellulose derivatives for single use

applications?

his monthly column is all about there a possibility to derive them from polyolefi ns as a solution, while others
openly sharing expertise and a renewable raw material in near future, still consider it nonviable.
Tknowhow with our readers, re- though there is a remote possibility of
gardless of industry, product or service. converting glucose to adipic acid by a A new worry in the form of
The aim is to plant the seeds of inspi- sequence of reactions – oxidation, de- microplastics has come about, and
ration, strengthen the knowledge base, hydration and hydrogenation. The cost scientists have even found microplastics
and hopefully, lead to new opportuni- of adipic acid so produced will be af- in human blood. That has retarded the
ties and innovations. fordable only if it is produced on a very possible introduction of additives that
large scale. Other raw materials would promote catalytic degradation of poly-
While the column is being rolled continue to be petrochemical-derived. olefi ns on a large scale.
out with the ideas of Prof. V.C. Malshe,
an academician, researcher, innovator, Another much talked about polymer Biomass as a feedstock
consultant and businessman, it is open is PLA. It is derived from lactic acid, The primary sources of biomass in
to one all. Simply write to editorial@ which, in turn, is produced by fermenta- India are agri-wastes like sugarcane
chemicalweekly.com. tion from maize, converted to a lactide, bagasse, rice & wheat straw and husk,
and then polymerised. Even though it is banana leaves, cotton stalk, foliage from
Options for single use plastics derived from agri-based raw materials, forests, wood, twigs, etc. The cumula-
There is a big movement to remove PLA is not readily biodegraded, needs tive annual availability of these types
single use plastics. The job is diffi cult. a catalyst, and has a density higher of wastes is estimated at about 840-mt.
Several solutions are being proposed. than polyethylene (PE). Hence, its con- About 30% by weight of biomass is
Some of the most common are: sumption (by weight) is about 1.5 times cellulose. Thus, there is a potential to
 Use of biodegradable plastics like more than that of low density polyethy- gather and recover about 250-mt of
polylactic acid (PLA), poly (glycolic lene (LDPE) or high density polyethy- cellulose every year.
acid) (PGA), polyvinyl alcohol lene (HDPE). As its price is currently
(PVA), starch-fi lled polyethylene, and 3-4 times that of HDPE, LDPE and Cellulose as a biopolymer raw
polybutylene adipate terephthalate polypropylene (PP), PLA replacement material
(PBAT). would be 4-6 times more expensive. Derivatives of cellulose such as
 Addition of catalysts that would Despite several announcements over cellulose triacetate (CTA), cellulose
make the plastics readily degrad- last 30 years, the world is yet to see a propionate (CP), cellulose acetate
able to safer, non-toxic molecules large PLA manufacturing facility, and butyrate (CAB), and nitrocellulose (NC)
like carbon dioxide (CO ), water, world production was below 500-kilo- have been products of commerce for
2
hydrocarbons, carboxylic acids, tonnes till 2022. over 100 years. These are environment
alcohols, ketones, etc. friendly, fully biodegradable and
 Use of alternate reusable, recyclable At the same time, the requirement renewable.
materials like metals, glass or paper. of single use, disposable plastics is in-
creasing day-by-day, as the proposed Every tonne of cellulose can yield
Of these, some are practical, and substitutes are not able to take substan- about double the weight of cellulose
should be considered and implemented. tial share of non-biodegradable plastics acetates. This is 250 times more than
like PE, PP and HDPE. Use of a food what the country will ever need annu-
Biodegradable plastics material (such as maize) to produce ally as disposable plastic.
Polybutylene adipate-co-tere- plastics is also being opposed by some
phthalate (PBAT), for example, is a organisations on grounds of poor sus- CTA was introduced in cigarettes as
polyester that is readily prepared from tainability. a tar fi lter over 50 years ago in India.
well-known raw materials like puri- About 50-kt of the polymer is imported
fi ed terephthalic acid (PTA), butylene Catalytic degradation of polyolefi ns annually in India for this application.
glycol, and adipic acid. None of these Some countries and some regulators Not a single cigarette fi lter burns off
raw materials is an agri-product, nor is have accepted catalytic degradation of during smoking. Has anyone seen a

174 Chemical Weekly February 25, 2025

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