Bioplastics and other alternatives of plastics
Helena Pokorná
Marie Ptáčková

Brief history of plastics
- Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main
ingredient
- Organic polymers
- Chemical modification of organic polymers
- Completely synthetic plastics

https://en.wikipedia.org/wiki/Plastic#History

- 1839 - discovery of vulcanization process (Charles Goodyear)
- 1907 - the world's first fully synthetic plastic Bakelite (Leo Baekeland)


Environmental effects of using plastics
- Plastics are resistant to many natural degradation processes
- Problematic of microplastics

https://en.wikipedia.org/wiki/Plastic#Environmental_effects

Solution of plastics pollution - Recycling

https://www.enespa.eu/en/what-is-the-difference-between-mechanical-and-chemical-recycling/
https://en.wikipedia.org/wiki/Plastic#Environmental_effects

Solution of plastics pollution - Decomposition of plastics
- Photo-oxidation process
- Decomposition of plastics by various types of bacteria, fungi or larvae

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165411/
https://www.mdpi.com/1422-0067/22/11/5610
https://www.sciencedirect.com/science/article/pii/S0160412020320614#s0085

Solution of plastics pollution – Alternative materials
- Using degradable materials
- Bioplastics

https://www.parekhplast.com/blog/bioplastics-classification-types-uses/

What is bioplastic?
- Biodegradable, biobased, or both


What is bioplastic?
- Biodegradable, biobased, or both
- Bioplastics represents 1% of
 world plastic production

Biobased and biodegradable bioplastics
- two ways of production
- Polymers are extracted
from biomass
- Polymers are produced
by microorganisms

Polymers extracted from biomass
- polymers
•starch, cellulose, lignin, chitin, carrageenan, agar, …
•casein, keratin
- biomass resources
•land crops (corn, potato, rice), seaweed, cotton
•wood industry byproducts (wood chips, sawdust)
•food waste (corn husks, fruit peels and seeds, spent coffee grounds)

From biomass to bioplastic
- polymer is extracted from biomass
- polymer is dissolved in water
- additional biopolymers, plasticizers, fillers are added
- melt-processing – gelatinization
- a film is made

Currently on the market
- Starch blends (TPS - thermoplastic starch)
•food packaging
•poor water resistance
- Polymers from algin and carrageenan
extracted from seaweeds
•edible food packaging
- Casein protein polymers
•adhesives, edible food packaging
•controlled release drug delivery systems

Currently on the market
- Cellulose acetate
•fibers, films
•hazardous substances
Obsah obrázku modrá, hračka Popis byl vytvořen automaticky
- Polylactic acid

Polylactic acid PLA
- Starch cleavage by heat or acids/enzymaticaly to glucose
- Fermentation of glucose to lactic acid
- Polymerization of lactic acid to PLA

Polylactic acid PLA
- Starch source: corn, cassava, …
- Properties:
•biodegradable?
•degradation rate between 3-5 years
•specific conditions (60 °C, moisture, soil or compost)

Polymers produced by microorganisms
- PHA (Polyhydroxyalkanoates) are the only biopolyesters completely synthesized by biological means

https://www.pbs.org/wgbh/nova/article/bacteria-plastic-biodegradable-pha-recycling/
https://www.researchgate.net/publication/321613995_Plastics_from_Bacteria_Natural_Functions_and_App
lications
https://sci-hub.se/https://doi.org/10.1016/j.rser.2021.111237

Polyhydroxyalkanoates PHA
image Fig. 2

https://sfamjournals.onlinelibrary.wiley.com/doi/10.1111/j.1365-2672.2007.03335.x

https://sci-hub.se/https://doi.org/10.1016/j.rser.2021.111237



Other alternatives

https://www.nature.com/articles/nchembio.580

Summary
Type of polymer
Production
Biodegradable
+
-
PLA
polylactic acid
microbial and chemical
Slowly and only under specific conditions (60 °C)
• suitable for wide variety of applications
• less energy for production
• problematic degradation
• occupation of land
• may decrease microbial diversity
Starch blends
chemical
Yes
• availabilty and low cost of starch
Poor gas barrier properties and water resistance
Seaweed polymers
chemical
Easily
• easy cultivation
• chemical-independent production
Low thermal stability
PHA
polyhydroxyalkanoates
microbial
Yes
• independence from the agricultural sector (cyanobacteria, microalgae)
• may increase microbial diversity in area of its degradation
High production price

Thank you
for your attention :)