Biodegradable Polymers

This is a world and an age of the highest-ever environmental consciousness, and correspondingly, a quest for sustainable alternatives to traditional materials cries out. One such class of materials is biodegradable polymers, which redefine the way one looks at waste management and conservation of the environment.

This Story also Contains

1. Understanding Biodegradable Polymers
2. Types and Applications of Biodegradable Polymers
3. Interest in the Academic Community and Applications in Real Life
4. Some Solved Examples
5. Conclusion

Understanding Biodegradable Polymers

Biodegradable polymers define a class of material degraded by the action of natural processes, Enzymatic or microbial degradation, into simpler substances to become innocuous to the environment. These polymers are largely derived from renewable resources, such as plant-based materials or microbial fermentation, and therefore ensure a more sustainable alternative to traditional plastics based on petroleum resources. While conventional plastics may take several hundred years before they can break down, biodegradable polymers can break down within a few months or years, depending, of course, on specific conditions.

Biodegradation consists of an initial fragmentation process of the polymer, followed by microbial colonization and subsequent enzymatic activity breaking down said fragments into end products such as water, carbon dioxide, and biomass. Thus, the process may be very variable in the presence of abiotic and biotic factors such as temperature, humidity, and microorganisms. This indicates that while designing biodegradable polymers, various factors need to be considered in order to ensure their complete degradation at a placed environment.

The large-scale utilization of synthetic polymers is based on their relatively greater inertness to the environmental processes. Given this characteristic, the degradation reactions that might lead to changes in the polymer's properties during the service life of its product do not occur. Advantages apart, due to this very property polymeric waste management has become very difficult. Overuse of such polymers has given birth to severe environmental problems and health hazards.
In biological systems, biopolymers break down chiefly by enzymatic hydrolysis and to a minor extent by oxidation. Keeping in view the polymer waste disposal issues and developing safe polymers for the use by humans, biodegradable synthetic polymers have been created. These synthetic polymers possess the functional groups found in biopolymers and lipids.
Aliphatic polyesters are an important class of biodegradable polymers because several of them are commercially potential biomaterials. Some examples include: Poly-?$\beta$-Hydroxybutyrate-Co-?$\beta$-Hydroxy-Valerate(PHBV), Nylon-2-Nylon-6, etc.

Types and Applications of Biodegradable Polymers

There are several types of biodegradable polymers with different characteristics and uses. One example could be polylactic acid, produced from renewable sources such as corn starch or sugarcane. Fields of application of PLA are very wide and vary from food packaging and disposable tableware to medical implants. Other examples include polyhydroxyalkanoates produced by bacteria, whose properties are very close to traditional plastics. PHA finds a broad application: from packaging materials to agricultural mulch films.

Others include starch-based polymers, largely used in packaging and disposables; and polycaprolactone, known for its elasticity and applied to varied fields such as controlled drug delivery systems or even biodegradable adhesives. Inherent in each class of biodegradable polymers are certain advantages coupled with their associated limitations, which finally make them useful or proper in a particular application. For example, while PLA is suitable for rigidity applications, PCL, being flexible, is very suitable for products that require bending or stretching.

Interest in the Academic Community and Applications in Real Life

The impact of biodegradable polymers extends to fields beyond waste management. They apply in tissue engineering and controlled drug delivery systems in medicine where intrinsic biocompatibility and biodegradability give advantages over other materials. For example, sutures made of biodegradable polymers are dissolved in the body after some time, obviating the need to be removed from the site surgically. Biodegradable mulch films applied in agriculture for suppression of weed growth and to ensure that the soil remains moist lower the requirements of chemical herbicides for weed control and ensure more and better yields. These naturally decompose and thus enrich the soil rather than add to plastic pollution.

Biodegradable polymers in the textile industry are used to obtain friendly fabrics at the end of their lifecycle through composting. More and more brands use these materials according to consumer demand, outlining the versatility of biodegradable polymers with huge potential across sectors. Other than this, new biodegradable materials with improved properties, strength, and durability are under development which further open up new fields for their application.

The interest in the research area of biodegradable polymers, as viewed from the academic circle, has received a warm reception from researchers and scientists around the world. Researchers continue to strive toward developing new routes for improving the properties and performance of such materials, coupled with the assessment of environmental impact and studies for possible applications that can be harnessed from these materials. With the enhanced need for sustainable solutions, the role of biodegradable polymers in academia and industry alike can only rise in the near future.

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Some Solved Examples

Example 1
Question: Which ones of the following are true about PHBV?
a) Biodegradable
b) Obtained by copolymerization of 3-hydroxy pentanoic acid and 3-hydroxybutyric acid
c) Used in orthopedic devices

1) All are wrong

2) Statement 1 only

3) Statements 1 and 2 only

4) All statements are correct

Solution: All statements are true. PHBV is biodegradable, it is obtained by copolymerization of 3-hydroxybutanoic acid and 3-hydroxypentanoic acid, and it is used in orthopedic devices. Therefore, the correct option is (4) a, b, c.

Example 2
Question: Poly β-hydroxybutyrate-co-β-hydroxyvalerate (PHBV) is a copolymer of?
1) 3-hydroxybutanoic acid and 4-hydroxypentanoic acid
2) 3-hydroxybutanoic acid and 3-hydroxyvaleric acid
3) 2-hydroxybutanoic acid and 3-hydroxybutanoic acid
4) 3-hydroxybutanoic acid and 2-hydroxybutanoic acid

Solution: The correct answer is (2) 3-hydroxybutanoic acid and 3-hydroxyvaleric acid. PHBV is synthesized from these two monomers.

Example 3
Question: The following structure belongs to which polymer?
1) Polyhydroxy Butyrate
2) Buna-N
3) Nylon2-nylon-6
4) Thiokal

Solution: The correct answer is (3) Nylon2-nylon-6, which is an alternating polyamide copolymer of glycine and aminocaproic acid and is biodegradable.

Example 4
Question: Which polymer has 'chiral' monomer(s)?
1) Buna-N
2) Neoprene
3) PHBV
4) Nylon 6,6

Solution: The correct answer is (3) PHBV, as both monomers in PHBV have a chiral center.

Conclusion

Biodegradable polymers represent one of the most emerging ways through which a solution could be provided pertaining to plastic waste globally by providing a sustainable alternative to traditional materials and opening a wide array of applications within various industries. One of the many advantages of their being able to degrade naturally in an extremely short period is mitigated environmental impact due to plastic pollution. From medical applications to agriculture and green textiles