SURFACE TENSION AND CHEMICAL CONSTITUTION PARACHOR

Surface tension to due to an inward force acting on the molecules at the surface of a liquid and is, therefore, considered to be dependent on the structure of molecules

The Parachor

In 1923, D.B. Macleod suggested an empirical relationship between the surface tension and density of a liquid, which may be stated as

                   

γgamm+a

𝛾

D-d=C

 where D and d are the densities and its vapour, respectively, y is the surface tension at the same temperature and C is a characteristic constant of the liquid                                               

S. Sugden (1924) obtained a relationship by multiplying Macleod equation with the molecular mam. M. of the liquid, and called the new constant as Parachor [P] 

 SURFACE TENSION AND CHEMICAL CONSTITUTION PARACHOR

Surface tension to due to an inward force acting on the molecules at the surface of a liquid and is, therefore, considered to be dependent on the structure of molecules

The Parachor

In 1923, D.B. Macleod suggested an empirical relationship between the surface tension and density of a liquid, which may be stated as                   

γgamm+a

𝛾

D-d=C

 where D and d are the densities and its vapour, respectively, y is the surface tension at the same temperature and C is a characteristic constant of the liquid

 . Sugden (1924) obtained a relationship by multiplying Macleod equation with the molecular mam. M. of the liquid, and called the new constant as Parachor [P] 

                 MY1-4/D-d=MC=[p]

At ordinary temperature, the density of vapour, d, is negligible as compared with D for the liquid, the equation (8) redues to

                 MY1-4/D=[p]

Or.            VmY1-4=[P]      (since M/D=Vm)

where Vm is the molar volume of the liquid. If surface tension y is unity (ie., gamma = 1 ) then equation (10) may be written as

                Vm=[p]

Thus, the Parachor [P] may be defined as the molar volume of a liquid at a temperature at which its surface tension is unity. It is approximately independent of temperature. It was shown by Sugden that Parachor is both additive and constitutive property and its value for any compound can be expressed as the sum of two sets of constants, one depending on the atoms present and the other upon the structural factor. The former is called atomic structural parachor and the latter is called structural parachor. 

For two liquids 1 and 2

             M1Y1 ¼ /D1.   = [p1]             (11)

             M2Y2  ¼ D2.  =[p2]               ( 12)

Divided equation(12)by Eq.(11),ifY1=Y2,we get

        [P1]/[P2]=M1Y1 ¼/D1÷M2Y2 ¼ /D2=M1/D1÷M2/D2=( Vm)1÷(Vm)2.                                      (13)

Thus, a comparison of parachor means, the comparison of molar veiumes under such conditions that the liquids have the same surface tensions.

Parachor and Chemical Constitution-Uses of Parachor in Elucidating Structures 

The comparison of experimental parachor values with the theoretically calculated calues of a compound helps us to decide about its chemical constitution as illustrated by the Following examples

Deciding constitution-Structure of Benzene If the Kekule formula for benzene be aneepted, the value of ita parachor can be calculated using Vogel's data

 

 6 carbon atoms.  6×8.6 = 51.6

 

 6 hydrogen atom.   6x15.7 = 94 2

 

 3 double bonds.   3x19.9 =59.7

 

 6 membered ring.              =1.4

 

Calculated parachor value for benzene =  206.9

 

 The experimental parachor value for benzene is 206.2. which is, therefore, in agreement with Kekule's formula.

 

Kekule formula:

           

        

Deciding the Nature of Valency Bonds.

 The parachor has also been found useful in providing information regarding the nature of bonds in certain groups. The nitre group (NO₂) for example, may be represented

      O                 O               0

_N \\            _N//             _N\

      \\                 \ O              \O

       O

1.                  II                  III

[P]= 98.9         [P]=74.1      [49.3]

The experimental value of parachor for - N * O_{2} group has been found to be 73.0. which is obviously in favour of the structure II.

 Existence of singlet linkage

Sugden suggested the existence of singlet linkage in compounds like PCI, and S*F_{0} A singlet linkage is a coordinate linkage formed by the donation of one electron onlythus in such a case we have the sharing of a single electron instead of the usual lone pair.

 

    (5 covalent linkage)        3 covalent and 2 single linkage

     [P]=316.9                      [P]=284

 

The experimental value for the parachor of PCls is 282.5, which is in agreement with the proposed structure (II) involving two singlet linkage and confirms the existence of two single-electron linkages in PCl, molecule. This prediction is supported by the observation that two of the chlorine atoms are easily eliminated on heating. 1

 

                    PCI→PCl3+ Cl₂

 

The Position of Substituent in an Aromatic Ring does not change the parachor value of the compound. The observed value of o-chlorotoluene is 280.8 and for p-chlorotoluene is 283.6. The theoretically calculated value for both the isomers is the same and is 283.3. Hence, the positional isomerism does not affect the parachor value.

 

 

 

                 MY1-4/D-d=MC=[p]

At ordinary temperature, the density of vapour, d, is negligible as compared with D for the liquid, the equation (8) redues to

                 MY1-4/D=[p]

 

Or.            VmY1-4=[P]      (since M/D=Vm)

 

where Vm is the molar volume of the liquid. If surface tension y is unity (ie., gamma = 1 ) then equation (10) may be written as

                Vm=[p]

 

Thus, the Parachor [P] may be defined as the molar volume of a liquid at a temperature at which its surface tension is unity. It is approximately independent of temperature. It was shown by Sugden that Parachor is both additive and constitutive property and its value for any compound can be expressed as the sum of two sets of constants, one depending on the atoms present and the other upon the structural factor. The former is called atomic structural parachor and the latter is called structural parachor.

 

For two liquids 1 and 2

             M1Y1 ¼ /D1.   = [p1]             (11)

             M2Y2  ¼ D2.  =[p2]               ( 12)

Divided equation(12)by Eq.(11),ifY1=Y2,we get

        [P1]/[P2]=M1Y1 ¼/D1÷M2Y2 ¼ /D2=M1/D1÷M2/D2=( Vm)1÷(Vm)2.                                      (13)

 

Thus, a comparison of parachor means, the comparison of molar veiumes under such conditions that the liquids have the same surface tensions.

 

 

 

 

 

Parachor and Chemical Constitution-Uses of Parachor in Elucidating Structures

 

The comparison of experimental parachor values with the theoretically calculated calues of a compound helps us to decide about its chemical constitution as illustrated by the Following examples

 

Deciding constitution-Structure of Benzene If the Kekule formula for benzene be aneepted, the value of ita parachor can be calculated using Vogel's data

 

 6 carbon atoms.  6×8.6 = 51.6

 

 6 hydrogen atom.   6x15.7 = 94 2

 

 3 double bonds.   3x19.9 =59.7

 

 6 membered ring.              =1.4

 

Calculated parachor value for benzene =  206.9

 

 The experimental parachor value for benzene is 206.2. which is, therefore, in agreement with Kekule's formula.

 

Kekule formula:

           

                 

 

Deciding the Nature of Valency Bonds.

 

 The parachor has also been found useful in providing information regarding the nature of bonds in certain groups. The nitre group (NO₂) for example, may be represented

      O                 O               0

_N \\            _N//             _N\

      \\                 \ O              \O

       O

1.                  II                  III

 

[P]= 98.9         [P]=74.1      [49.3]

 

The experimental value of parachor for - N * O_{2} group has been found to be 73.0. which is obviously in favour of the structure II.

 

Existence of singlet linkage

Sugden suggested the existence of singlet linkage in compounds like PCI, and S*F_{0} A singlet linkage is a coordinate linkage formed by the donation of one electron onlythus in such a case we have the sharing of a single electron instead of the usual lone pair.

 

    (5 covalent linkage)        3 covalent and 2 single linkage

     [P]=316.9                      [P]=284

 

s

 

The experimental value for the parachor of PCls is 282.5, which is in agreement with the proposed structure (II) involving two singlet linkage and confirms the existence of two single-electron linkages in PCl, molecule. This prediction is supported by the observation that two of the chlorine atoms are easily eliminated on heating. 1

 

                    PCI→PCl3+ Cl₂

 

The Position of Substituent in an Aromatic Ring does not change the parachor value of the compound. The observed value of o-chlorotoluene is 280.8 and for p-chlorotoluene is 283.6. The theoretically calculated value for both the isomers is the same and is 283.3. Hence, the positional isomerism does not affect the parachor value.

 

 

SURFACE TENSION

Molecules in the interior of a liquid are attracted equally in all directions by the Fig 3.2 O molecules around it, and are thus subjected to a balanced set of forces, whereas molecules at the surface are attracted only towards the interior as shown in Fig. The attractions pull the surface layer toward the centre, because of the difference in the strength of interactions of the surface molecule with the molecule in the vapour phase and one that is in the bulk below it. As a result of the inward attraction the surface of the liquid experiences an attractive force known as surface tension and surface behaves like a stretched membrane. That is why the surface of any liquid tends to minimize its surface area. A droplet assumes a spherical shape because a sphere has the minimum surface area for a given volume.

The Surface Tension is defined as the force in netwtons acting at right angle on a unit length (Im) along the surface of a liquid. It is denoted by (gamma). The SI unit of surface tension is newton per meter (Nm). Note that the units of Nim, are equivalent to joules per square meter,jm-2.

Surface tension is related to the attractive forces between molecules Liquids with large attractive forces have relatively large surface tensions. The large surface tension of Surface tension is related to the attractive forces between molecules Liquids with Effect of Temperature. The surface tension of a liquid decreases with increasing water is mainly due to more extensive hydrogen bonding in the water structure temperature and becomes zero near the critical temperature.

Capillary Action. The rise or fall of a liquid in a capillary tube is related to the surface depressed, like mercury, depends on the relative magnitude of the forces of cohesion tension of the liquid. Whether a liquid rises in a glass capillary, like water, or is depressed, like mercury, depends on the relative magnitude of the forces of cohesion tension of the liquid. Whether a liquid rises in a glass capillary, like water, or is between the liquid molecules themselves, and the forces of adhesion between the liquid and the walls of the tube These forces determine the contact angle 0, which the liquid makes with the walls of the tube. If a contact angle is less than 90, the liquid is said to wet the surface and a concave meniscus is formed. If the contact angle is greater that 90. the liquid does not wet the surface and a convex meniscus is formed.

The formation of a concave meniscus by a liquid that gets the glass leads to a capillary rise,the formation of a concave meniscus leads to the depression of the liquid (which does not wet the glass) in a capillary tube.

MEASUREMENT OF SURFACE TENSION

 The methods commonly employed for the measurement of surface tension are A fine capillary tube of radius is vertically

The Capillary Rise Method.

A fine capillary tube of radius r is vertically immersed in a test liquid that wets glass. The liquid rises to a certain height 'a' until the force of surface tension pulling the liquid upward is counterbalanced by the downward hydrostatic force.

The force of surface tension (i.e.. upward force) acting along the total circumference of the tube is 2tr y cos 0. The hydrostatic force fie., downward force) is equal to the product of pressure and area of cross-section of the tube (=ghdpir2)

 

But Upward force   = downward force

          2pirYcos0.   =   ghdpi r2

 

           Y = ghdr/2cos0

 

where y is the surface tension, d is the density of the liquid, g is the acceleration due to gravity and o is the contact angle. For most liquids, 0 is essentially zero, and ens 01 Therefore, Eq (1) reduces to

             Y ghdr/ 2

 In order to calculate the value of y, one needs to know the values of g.h.d and r.

DROP FORMATION METHOD

The size and hence the weight of a drop of a liquid falling from the end of a capillary tube depends upon the surface tension of the liquid and the sou the outer circumference of the tube. The weight of drop pulls it. When the two forces are of the capillary end. The drop is supported by the upward force of surface tension acting balanced, the drop breaks. Thus at the point of breaking

 γ. 2pir    =  W  = mg  =  Vdg

where,r  is the radius of the capillary tube. V is the volume of the drop and d is its  density.This equations being a basis of the drop Method is used for the comparison of the surface tensions of different liquids  

Drop Weight Method:

 In this method, the mass of a single drop of liquid, and that of reference liquid (say water) is determined. Then from Eq.(5), and

W1= m1g= 2pirY1

 W₂mg = 2pi r Y2

Therefore Y1/Y2 = m1/m2

 

Knowing the surface tension of reference liquid, that of the experimental liquid can be determined.

 

DROP-NUMBER METHOD:

Drop-Number Method Instead of finding the weights of single drops, it is easier to count the number of drops formed from an equal volume of two liquids If n. and nare the number of drops produced from the same volume V of the two liquids, then

 

.The volume of a single drop of liquid 1 = V/n1

.The mass of a single drop of liquid 1 V/n1 d1 .Similarly, the mass of a single drop of liquid 2 V/n2 d2

Y1/Y2= (V/n1)d1/(V/n2)d2 =n2d1/n1d2 or Y1 = n2d1/n1d2 Y2

The instrument used for determining surface tension is called stalagmometer, which consists of a bulb fused with a capillary tube as shown in Fig.3.7. The stalagmometer is thoroughly cleaned and water is sucked up to the upper mark A. The water is allowed to flow and the number of drops is counted until the lower mark B is reached. Next the experiment is repeated with the other (experimental) liquid and surface tension of the liquid can be determined by using the Eq.(7). For reference liquid water, Eq.(7) can be written as:

Y1= d1 /dw×nw/n1×Yw

 

 

Bioplastic

 

History:
1. Early Beginnings: The concept of bioplastics dates back to the early 20th century.
2. 1920s: The first bioplastic, cellulose acetate, was developed from wood pulp and cotton
linters.
3. 1950s-1980s: Starch-based bioplastics were developed from corn, wheat, and potato starch.
4. 1990s-Present: Modern bioplastics, such as PLA and PHA, were developed from renewable
resources.
Nowadays, companies and laboratories of all sizes keep researching the field. Many of them are
already producing biodegradable and compostable alternatives to petroleum-based plastics.
Consumers and even companies prefer to purchase safer and more environmentally friendly
products as the public environmental conscience is increasing.

introduction:
• Bioplastics are a type of plastic made from renewable biological sources, such as plants,
microorganisms, or agricultural waste. They are designed to replace traditional plastics,
which are derived from fossil fuels and contribute to greenhouse gas emissions. They
are alternative plastic source with similar physical properties to synthetic plastics.
• These biopolymers can be produced through various methods, including fermentation,
enzymatic conversion, or chemical synthesis.
4
• Bioplastics offer a sustainable alternative to traditional plastics, reducing dependence
on fossil fuels and promoting environmentally friendly practices.

Plastics have become an essential part of modern society. Many of the products we use
in our daily lives are made of plastics. Plastics are crucial in various industries like
transportation, food, healthcare, and energy.
• Bioplastics are alternatives to fossil-based conventional plastics that are made from
renewable sources like plant biomass. They are often 100% bio-based and are
considered sustainable as they reduce reliance on fossil resources, introduce ecofriendly disposal options, and use less toxic production methods.
Why Bioplastic?
• They providing energy savings in production. They do not involve the consumption of
non-renewable raw materials. Their production reduces non-biodegradable waste that
contaminates the environment. They do not contain additives that are harmful to
health, such as phthalates or bisphenol A.
• Due to lack of proper disposal of these plastics, these effect wild life and aquatic life.
• Bioplastics can be produced more efficiently than traditional plastics, reducing energy
consumption and greenhouse gas emission.
• Bioplastics can reduce carbon footprint by up to 80%.
• Plastic derived from crude oil such as petroleum rely more on scare fossil fuels.
• When plastics made from petroleum are burned they release the carbon dioxide
contained in the petroleum into the atmosphere, leading of global warming
Types of Bioplastic:
There are following types of bioplastic:
1. Starch -based bioplastic
2. Cellulose-based bioplastic
3. Protein-based bioplastic
4. Aliphatic polyesters bioplastic
• Polylactic acid bioplastic (PLA)
• Poly-3-hydroxybutyrate
• Polyhydroxyalkanoates (PHA)
5. Bio -derived polyethylene
Starch-based Bioplastic:
• Simple bioplastic derived from corn starch.
• Often mixed with biodegradable polyesters.
• Example: Green Dot Bioplastics has successfully developed cell phone cases from
compostable, starch-based plastics. Additional opportunities are expected in
compostable yard and kitchen bags, food service disposables and various types
of packaging.
• In the food industry starch is used as a thickener in the preparation of cornstarch
puddings, custards, sauces, cream soups, and gravies. Starch from tubers and
cereals provides the carbohydrate of the human diet. Large quantities of starch
and its derivatives are used in the paper and textile industries
Cellulose-based bioplastic:
• Cellulose plastics are bioplastics manufactured using cellulose or derivatives of cellulose.
Cellulose plastics are manufactured using softwood trees as the basic raw material.
• Produced using cellulose esters and cellulose derivatives
• Example: Major applications for cellulose plastics include thermoplastics, extruded films,
eyeglass frames, electronics, sheets, rods, etc.
• Molding materials is the most dominant application segment for cellulose plastics and
the trend is expected to continue. Plastic is produced mainly using nonrenewable
resources such as crude oil and its several derivatives owing to which, the carbon
footprint is high in the production of cellulose plastics.
•
Protein-based bioplastic:
• Protein-based bioplastics are made from natural proteins such as soy protein, whey
protein, and zein. There are so many raw materials suitable for the production of
protein plastics, which are of animal origin or plant origin.
• Produced using protein sources such as wheat gluten, casein and milk
• Example: Biopolymers that are protein-based have become a leading alternative for
food packaging. There have been major advances in protein-based films and coatings for
food packaging made from plant and animal proteins.
t is due to their biodegradability and natural origins, which help us deal with plastic
pollution. Besides, a key feature of these bioplastics is their antimicrobial activity, which
is beneficial to the food industry, pharmaceuticals, medicine, agriculture, etc.
Aliphatic polyesters bioplastic:
• A collection of bio-based polyesters including PLA, PHB, PGA, among others.
• They are all more or less sensitive to hydrolytic degradation, aka they are sensitive to
water, and can be mixed with other compounds.
• Example: Some bio-based polyesters that have gained commercial use or that are
currently being investigated are polylactic acid (PLA), polyglycolic acid (PGA), poly-ε-
caprolactone (PCL), polyhydroxybutyrate (PHB), and poly(3-hydroxy valerate). However,
only a small number of them are commercially available.
• Aliphatic polyesters are biodegradable polymers widely used in biomedical and
pharmaceutical engineering. Polymers are large molecules containing repeating
subunits, and polyesters consist of repeating ester groups. Aliphatic molecules exist in a
long straight chain rather than a ring.
• There are three other types of aliphatic polyesters bioplastic, include;
• Polylactic acid Bioplastic (PLA):
• Polylactic acid, also known as PLA, is a thermoplastic monomer derived from renewable,
organic sources such as corn starch or sugar cane.
PLA is used in a large variety of consumer products such as disposable tableware,
cutlery, housings for kitchen appliances and electronics such as laptops and handheld
devices, and microwavable trays. However, PLA is not suitable for microwavable
containers because of its low glass transition temperature.
8
• Poly-3-hydroxybutyrate:
• Poly(3-hydroxybutyrate) (P3HB) is a highly crystalline, linear polyester of 3-
hydroxybutyric acid, is generated as a carbon reserve in a wide variety of bacteria, and is
produced industrially through fermentation of glucose by the bacterium Alcaligenes
eutrophus.
• Poly-3-hydroxybutyrate is a biopolymer which has shown tremendous potential for
replacing conventional petroleum-based plastics for plummeting the plastic pollution
problem. However, the production cost of PHB is high which makes it less attractive for
commercial use
Polyhydroxyalanoates(PHA):
• Polyhydroxyalkanoates or PHAs are polyesters produced in nature by numerous
microorganisms, including through bacterial fermentation of sugars or lipids. When
produced by bacteria they serve as both a source of energy and as a carbon store.
• Polyhydroxyalkanoates (PHAs) are polyesters that contain a characteristic bond of
esters, which are accumulated as carbon and energy reserve along with limited nitrogen
source and assist in providing energy.
9
• Bio-derived polyethylene:
• Bioderived polyethylene is produced using the same process, the only difference being
that, rather than use ethane derived from crude oil distillation it uses ethanol which has
been produced by fermenting a biomass material such as corn starch or cane sugar.
• PE is non-biodegradable and contributes significantly to the world's plastic waste
products. 3R methodology and recycling approaches are proposed as a solution to
address PE pollution. The chemical modification and structure of PE could enhance the
degradation level.
• They are used in packaging, electronics, catering, gardening, medical products and
more. The production process and carbon cycle of bioplastics is also outlined.
Classification of bioplastic :
• Bioplastic can be classified based on their origin, composition and properties:
1. Origin-Based Classification:
1. Bioplastics from renewable resources: Made from plants, microorganisms, or agricultural
waste.
2. Bioplastics from fossil resources: Made from fossil fuels, but produced through biological
processes.
2. Composition-Based Classification:
1. Polylactic Acid (PLA): Made from corn starch, sugarcane, or potato starch.
10
2. Polyhydroxyalkanoates (PHA): Produced from bacterial fermentation of sugarcane or potato
starch.
3. Polybutylene Succinate (PBS): Made from corn starch, sugarcane, or potato starch.
4. Starch-based bioplastics: Derived from corn, wheat, potato, or tapioca starch.
3. Property-Based Classification:
1. Biodegradable bioplastics: Can break down naturally in the environment.
2. Compostable bioplastics: Can be composted at home or in industrial facilities.
3. Durable bioplastics: Have similar properties to traditional plastics.
4. Thermoplastic bioplastics: Can be melted and reformed multiple times.
4. Application-Based Classification:
1. Packaging bioplastics: Used in food containers, water bottles, and cutlery.
2. Textile bioplastics: Used in clothing, upholstery, and biomedical applications.
3. Automotive bioplastics: Used in car parts, dashboards, and interior components.
4. Medical bioplastics: Used in implants, surgical instruments, and diagnostic devices.
Properties of Bioplastic:
• Strong and ductile.
• Poor conductors of heat and electricity.
• Easily moulded into different shapes and size.
• Resist corrosion and are resistant to many chemicals.
• Along with the growth in variety of bioplastic materials, properties, such as flexibility,
durability, printability, transparency, barrier, heat resistance, gloss and many more have
been significantly enhanced.
• The physical properties of bioplastic were observed, including tensile strength,
elongation, color, moisture content, water vapor transmission rate (WVTR), FTIR, DSC
and SEM. This research aimed to study the physical properties of bioplastic
agar/chitosan produced through rheomix.
• Mostly, bioplastic materials are used because they have desirable mechanical properties
such as tensile strength and elongation at break. For this reason, the mechanical
properties may be considered as the most important of all the physical properties of
bioplastic for most applications.
• Applications-Specific Properties:
1. Packaging: Bioplastics offer excellent barrier properties for packaging applications.
2. Textiles: Bioplastics provide softness, breathability, and moisture-wicking properties for
textiles.
3. Automotive: Bioplastics exhibit high impact resistance and thermal stability for
automotive applications.
4. Medical: Bioplastics offer biocompatibility and biodegradability for medical applications.
• Environmental Properties:
1. Renewable Resource-Based: Bioplastics are made from renewable resources.
2. Carbon Footprint: Bioplastics have a lower carbon footprint than traditional plastics.
3. Non-Toxic: Bioplastics are non-toxic and environmentally friendly.
4. Biodegradable: Bioplastics break down naturally in the environment.
12
Biomaterial trend of Bioplastic:
• The development of bio-based materials with improved properties and applications is a
result of collaborations between material companies, researchers, and manufacturers.
As the market continues to expand, bioplastics play a crucial role in reducing the
environmental impact caused by the use of traditional plastics.
• Soil contains a wide diversity of microorganisms, making plastic biodegradation more
feasible than in other environments such as water and air. A number of microorganisms
isolated from soil media utilized bioplastic as a carbon source.
• The biodegradation of polymers depends on the chemical nature of the polymer as well
as on environmental factors, such as moisture, temperature, acidic nature, etc. Including
these factors, bioplastics biodegrade differently in different soil compositions.
• There is no doubt that the aquatic environment is the most susceptible to plastic
contamination. However, bioplastic degradation in both seawater and fresh water
generally appears to be slower than biodegradation in composting, anaerobic digestion,
and soil environments.
• Several bacteria species were capable of degrading bioplastics in aquatic environments,
such as river water and marine environments; Bacillus, Lepthotrix, Tenacibaculum,
Pseudomonas, Entrobacter, Variovorax Gracilibacillus, and Avanivorax were isolated
from these environments.
Figure: Interactions of microbes and environmental factors in microplastic-contaminated soils.
13
Applications of Bioplastic:
• Bioplastics can be used in a wide range of applications, such as packaging, agricultural
films, disposable utensils, and even automotive parts.
• Today, bioplastics can be found in the following market segments:
• Packaging
• Food-services
• Agriculture & horticulture
• Consumer electronics
• Automotive & transport
• Consumer goods and household appliances
• Building & construction
• Coating & adhesives
• Fibers
1. Packaging: Bioplastics are used in packaging materials, such as containers, bottles, and
wrapping films.
2. Textiles: Bioplastics are used in clothing, upholstery, and medical textiles.
3. Automotive: Bioplastics are used in car parts, such as dashboards and interior components.
4. Medical: Bioplastics are used in medical devices, implants, and pharmaceutical packaging.
5. Agriculture: Bioplastics are used in mulch films, plant pots, and seed coatings.
6. Consumer Products: Bioplastics are used in personal care products, such as shampoo bottles
and toothbrushes.
7. 3D Printing: Bioplastics are used as printing materials for 3D printing.
8. Compostable Bags: Bioplastics are used to make compostable bags for food waste and other
organic materials.
9. Cutlery: Bioplastics are used to make biodegradable cutlery, such as forks, knives, and spoons.
14
10. Disposable Products: Bioplastics are used to make disposable products, such as plates, cups,
and straws.
Environmental impacts of Bioplastic:
Bioplastics, made from renewable resources, offer a sustainable alternative to traditional
plastics. However, their environmental impacts are multifaceted:
Positive Impacts:
1. Renewable resources: Bioplastics are made from renewable resources, reducing dependence
on fossil fuels.
2. Biodegradable: Some bioplastics are biodegradable, reducing plastic waste.
3. Lower greenhouse gas emissions: Bioplastics can reduce greenhouse gas emissions during
production.
4. Compostable: Some bioplastics can be composted, reducing waste.
Negative Impacts:
15
1. Land use and competition with food crops: Large-scale bioplastic production may compete
with food crops for land.
2. Water consumption: Bioplastic production requires significant water resources.
3. Energy consumption: Bioplastic production requires energy, potentially contributing to
greenhouse gas emissions.
4. End-of-life management: Bioplastics may not biodegrade as expected, contributing to plastic
waste.
5. Lack of infrastructure: Bioplastic recycling infrastructure is limited.
6. Cost and scalability: Bioplastics are currently more expensive than traditional plastics.
Future Directions:
1. Advanced biotechnologies: Develop novel biotechnologies for efficient bioplastic production.
2. Bioplastic blends: Create bioplastic blends with improved performance and biodegradability.
3. Closed-loop systems: Design closed-loop systems for bioplastic production, use, and
recycling.
4. Life cycle assessments: Conduct thorough life cycle assessments to evaluate bioplastic
environmental impacts.
Benefits of Bioplastic:
1. Renewable Resources: Bioplastics are made from renewable resources such as corn starch,
sugarcane, or potato starch, reducing dependence on fossil fuels.
2. Biodegradable: Bioplastics can break down naturally in the environment, reducing plastic
waste and pollution.
3. Compostable: Some bioplastics can be composted at home or in industrial facilities, creating
nutrient-rich soil.
4. Reduced Greenhouse Gas Emissions: Bioplastics can reduce greenhouse gas emissions
during production and use.
5. Conservation of Fossil Fuels: Bioplastics conserve fossil fuels by using renewable resources.
16
Economic Benefits:
1. Job Creation: Bioplastic industry creates jobs in manufacturing, research, and development.
2. New Markets: Bioplastics open new markets for renewable resources and sustainable
products.
3. Cost Savings: Bioplastics can reduce costs associated with traditional plastic production.
Environmental Benefits:
1. Reduced Plastic Pollution: Bioplastics reduce plastic pollution in oceans and landfills.
2. Protected Biodiversity: Bioplastics help protect biodiversity by reducing plastic waste and
pollution.
3. Soil Conservation: Bioplastics promote soil conservation through composting.
Social Benefits:
1. Increased Awareness: Bioplastics raise awareness about sustainable living and
environmental conservation.
2. Improved Public Health: Bioplastics reduce exposure to toxic chemicals in traditional plastics.
3. Community Engagement: Bioplastic initiatives engage communities in sustainable practices.
Relation with Chemistry:
Bioplastics are closely related to chemistry, as their production, properties, and
applications involve various chemical principles and processes.
• Chemical Composition:
Bioplastics are made from renewable resources such as:
1. Polysaccharides (starch, cellulose)
2. Proteins (casein, zein)
3. Lipids (fatty acids)
4. Biopolymers (PLA, PHA)
• Chemical Reactions:
Bioplastic production involves various chemical reactions, including:
1. Polymerization (PLA, PHA)
2. Hydrolysis (starch breakdown)
3. Condensation (polymer formation)
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4. Fermentation (microbial production)
• Chemical Properties:
Bioplastics exhibit unique chemical properties, such as:
1. Biodegradability
2. Compostability
3. Thermal stability
4. Mechanical strength
• Green Chemistry:
Bioplastics align with green chemistry principles, promoting:
1. Renewable resources
2. Biodegradability
3. Non-toxicity
4. Sustainable development.
Challenges and future prospects:
• Challenges of Bioplastics:
1. Cost: Bioplastics are currently more expensive than traditional plastics.
2. Scalability: Bioplastic production needs to be scaled up to meet demand.
3. Performance: Bioplastics may not have the same strength or durability as traditional plastics.
4. Infrastructure: Bioplastic recycling and composting infrastructure is limited.
5. Feedstock availability: Bioplastic production relies on renewable resources, which can be
affected by climate change and agricultural practices.
6. Competition with food crops: Bioplastic production may compete with food crops for land
and resources.
7. Regulatory framework: Bioplastics need clear regulations and standards for production, use
and disposal.
8. Public awareness: Bioplastics need increased public awareness and education about their
benefits and limitations.
• Future Prospects of Bioplastics:
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1. Increased demand: Growing demand for sustainable packaging and products.
2. Technological advancements: Improvements in production processes and material
properties.
3. New feedstocks: Development of new renewable resources, such as agricultural waste.
4. Biodegradable plastics: Development of biodegradable plastics that can replace traditional
plastics.
5. Compostable plastics: Increased use of compostable plastics in packaging and disposable
products.
6. Sustainable agriculture: Bioplastics can promote sustainable agriculture practices and reduce
waste.
7. Closed-loop systems: Development of closed-loop systems for bioplastic production, use and
recycling.
8. International cooperation: Global collaboration to establish standards, regulations and best
practices.
Conclusion:
• Bioplastics offer a promising solution to reduce plastic waste and mitigate
environmental impacts. Made from renewable resources, bioplastics provide a
sustainable alternative to traditional plastics. With their biodegradable and
compostable properties, bioplastics can minimize plastic pollution and promote
a circular economy.
Bioplastics are biobased polymers that are produced from renewable resources
including carbohydrates, vegetable oils, etc. in the presence of microorganisms.
By addressing challenges and leveraging opportunities, bioplastics can play a
vital role in creating a more sustainable future, reducing plastic waste and
promoting eco-friendly practices.