PHD
  1. Inorganic chemistry  1.1. Coordination chemistry  1.1.1. Ligand field theory  1.1.2. Crystal field theory  1.1.3. Molecular Orbital Theory for Coordination Compounds  1.1.4. Stability of Coordination Compounds  1.1.5. Electronic spectra of coordination compounds  1.1.6. Isomerism in Coordination Compounds  1.1.7. Kinetics and mechanism of coordination reactions  1.2. Organometallic Chemistry  1.2.1. Metal Carbonyls  1.2.2. Metal alkyl and aryl  1.2.3. Fischer and Schrock carbonaceans  1.2.4. Oxidative Addition and Reductive Elimination  1.2.5. Metal Hydrides  1.2.6. Catalysis by organometallic compounds  1.2.7. Metallocenes and Sandwich Complexes  1.2.8. CH activation  1.3. Solid state chemistry  1.3.1. Crystal structures and lattices  1.3.2. Band theory and electrical properties  1.3.3. Defects in the crystal  1.3.4. Synthesis of solid state materials  1.3.5. Magnetic and optical properties of solids  1.3.6. Superconductivity  1.3.7. Solid state ionics  1.4. Bio-inorganic chemistry  1.4.1. Metalloproteins and enzymes  1.4.2. Metal ion transport and storage  1.4.3. The role of metals in medicine  1.4.4. Bioinspired catalysis  1.4.5. Metal–DNA interactions  1.4.6. Metal Complexes in Medical Science  1.5. Lanthanides and Actinides  1.5.1. Electronic configuration and oxidation states in lanthanides and actinides  1.5.2. Spectral and Magnetic Properties in Lanthanides and Actinides  1.5.3. Separation and Extraction of Lanthanides and Actinides  1.5.4. Coordination chemistry of f-block elements  1.6. Main Group Chemistry  1.6.1. Chemistry of boron compounds  1.6.2. Chemistry of Silicon and Germanium Compounds  1.6.3. Chemistry of Phosphorus and Sulfur Compounds  1.6.4. Organosilicon chemistry  1.6.5. Noble Gas Chemistry
  2. Organic chemistry  2.1. Reaction mechanism  2.1.1. Nucleophilic substitution reactions  2.1.2. Electrophilic addition and substitution reactions  2.1.3. Elimination reactions  2.1.4. Rearrangement reactions  2.1.5. Radical reactions  2.1.6. Pericyclic Reactions  2.1.7. Photochemical reactions  2.2. Stereoscopic  2.2.1. Chirality and optical activity  2.2.2. Structural analysis  2.2.3. Stereoelectronic effects  2.2.4. Asymmetric synthesis  2.2.5. Dynamic Stereochemistry  2.3. Organometallic Chemistry in Organic Synthesis  2.3.1. Organolithium and organomagnesium reagents  2.3.2. Transition metal catalyzed coupling reactions  2.3.3. Palladium-catalyzed reactions  2.3.4. Olefin Metathesis  2.3.5. Gold and silver catalysis  2.4. Natural products chemistry  2.4.1. Alkaloids and terpenoids  2.4.2. Steroids and Flavonoids  2.4.3. Total synthesis of natural products  2.4.4. Biosynthesis of natural products  2.5. Supramolecular Chemistry  2.5.1. Host-Guest Chemistry  2.5.2. Self-assembly and molecular recognition  2.5.3. Supramolecular Catalysis  2.5.4. Molecular Machines
  3. Physical Chemistry  3.1. Thermodynamics  3.1.1. Laws of Thermodynamics  3.1.2. Chemical Potential and Equilibrium  3.1.3. Statistical thermodynamics  3.1.4. Non-equilibrium thermodynamics  3.2. Quantum Chemistry  3.2.1. Schrödinger equation and its applications  3.2.2. Molecular orbital theory  3.2.3. Density functional theory  3.2.4. Post-Hartree–Fock methods  3.3. Chemical kinetics  3.3.1. Reaction rate theory  3.3.2. Mechanism and rate laws  3.3.3. Catalysis and enzyme kinetics  3.3.4. Reaction dynamics  3.4. Spectroscopy and molecular structure  3.4.1. Infrared Spectroscopy  3.4.2. UV-visible spectroscopy  3.4.3. Nuclear Magnetic Resonance Spectroscopy  3.4.4. Mass Spectrometry  3.4.5. Raman Spectroscopy  3.5. Surface and Colloid Chemistry  3.5.1. Absorption and Catalysis  3.5.2. Surfactants and micelles  3.5.3. Colloidal Stability  3.5.4. Nanomaterials and Interfaces
  4. Analytical chemistry  4.1. Chromatography  4.1.1. Gas Chromatography  4.1.2. High Performance Liquid Chromatography  4.1.3. Thin Layer Chromatography  4.1.4. Ion Chromatography  4.2. Electroanalytical techniques  4.2.1. Voltammetry and Polarography  4.2.2. Conductometry and potentiometry  4.2.3. Colometry  4.3. Spectroscopic Methods  4.3.1. Atomic absorption spectroscopy  4.3.2. Fluorescence Spectroscopy  4.3.3. X-ray diffraction  4.3.4. Electron paramagnetic resonance spectroscopy  4.4. Chemometrics  4.4.1. Data processing and statistical methods  4.4.2. Multidisciplinary analysis  4.4.3. Machine Learning in Analytical Chemistry
  5. Theoretical and Computational Chemistry  5.1. Molecular dynamics simulation  5.2. Quantum chemistry methods  5.3. Computational drug design  5.4. Machine Learning in Chemistry  5.5. Ab initio molecular dynamics
  6. Biophysics and Medicinal Chemistry  6.1. Drug discovery and design  6.2. Enzyme kinetics and inhibition  6.3. Chemical biology approach  6.4. Protein-ligand interactions  6.5. Bioorthogonal chemistry
  7. Materials chemistry  7.1. Polymer chemistry  7.1.1. Polymerization mechanism  7.1.2. Functional Polymers  7.1.3. Biodegradable Polymer  7.1.4. Conducting and semiconducting polymers  7.2. Nano Chemistry  7.2.1. Nanoparticles and nanostructures  7.2.2. Carbon-based nanomaterials  7.2.3. Quantum dots  7.3. Energy and Environmental Chemistry  7.3.1. Battery and Fuel Cell Chemistry  7.3.2. Green chemistry and sustainable materials  7.3.3. Photocatalysis

PHD → Materials chemistry ↓


Polymer chemistry


Polymer chemistry is an important field within materials chemistry that focuses on the chemical synthesis and properties of polymers or macromolecules. A polymer is a large molecule composed of repeating structural units, usually linked by covalent chemical bonds. This fascinating field of chemistry has a profound influence in diverse industries, including plastics, rubber, textiles, and even biotechnology. In this comprehensive guide, we will explore the main concepts of polymer chemistry, its processes, and its applications in simple and understandable terms.

What are polymers?

Polymers are made up of long, repeating chains of molecules. These chains are made up of individual units known as monomers. A basic understanding of polymers begins with understanding these two components:

  • Monomers: The building blocks of polymers. They are small molecules that can join together to form a larger structure.
  • Polymers: Large molecules made by linking many monomers together. These can be naturally occurring or synthetic.
H2C=CH2 + H2C=CH2 + ... → -CH2-CH2-CH2-CH2-CH2-...

The above equation shows the formation of the polymer from ethylene (C2H4) monomers.

Types of polymers

Polymers can be classified based on various criteria, such as their origin, structure, and type of polymerization. Here are the main classifications:

Based on origin

  • Natural polymers: These occur naturally and include proteins, DNA, cellulose, and natural rubber.
  • Synthetic polymers: These are man-made polymers, such as polyethylene, polystyrene, and nylon.

Based on structure

  • Linear polymers: Made up of a straight chain of monomers. 
    -AAAA-
  • Branched polymers: Have branches different from the main chain. 
    -AAA- | A
  • Cross-linked polymers: The chains are connected through links. This often forms a three-dimensional network. 
    -AAA- | | | -AAA-

Based on the method of polymerization

  • Addition polymer: Formed by the addition of monomer units without any by-products. An example of this is the manufacture of polyethylene.
  • Condensation polymers: Formed by the combination of monomers and the elimination of small molecules such as water, e.g., polyester.

Polymerization processes

Polymerization is the chemical process in which monomers are linked together to form a polymer. There are two main types of polymerization:

Addition polymerization

Also known as chain-growth polymerization, this process involves the addition of unsaturated monomers, which contain double or triple bonds. The polymerization begins with an initiator that helps open the bonds, allowing the monomers to bind together.

Initiator + H2C=CH2 → I-CH2-CH2* I-CH2-CH2* + H2C=CH2 → I-CH2-CH2-CH2-CH2* ...

Condensation polymerization

This process, also known as step-growth polymerization, involves the coupling of monomers and the release of a small molecule such as water or methanol. An example of condensation polymerization is the formation of nylon from a diamine and a diacid.

HOOC-R-COOH + H2N-R'-NH2 → -OC-R-CO-NH-R'-NH- + H2O

Properties of polymers

The properties of polymers depend on the chemical composition and structure of the polymer chains. Some of the important properties of polymers are as follows:

Mechanical properties

These include tensile strength, elasticity, and toughness. Polymers such as rubber exhibit excellent elasticity, while materials such as epoxy are known for their strength and durability.

Thermal properties

Polymers can exhibit different behaviors when heated. For example, thermoplastics become flexible or moldable after heating while thermosetting polymers become permanently rigid after heating.

Chemical resistance

Many polymers are highly resistant to chemical attack. This property allows them to be used as protective coatings or packaging materials.

Optical properties

Polymer materials can vary in clarity, opacity, and color depending on their structure and composition. For example, poly(methyl methacrylate) (PMMA) is used as a substitute for glass due to its clarity.

Applications of polymers

Polymers play important roles in everyday life, and their applications are vast and varied:

Plastic

The most widespread use of polymers is in the plastics industry. Polymers such as polyethylene, polypropylene, and polyvinyl chloride (PVC) are used in the manufacture of countless plastic products.

Rubbers

Elastomers or rubbers are polymers with elasticity. Natural rubber and synthetic rubbers such as styrene-butadiene rubber (SBR) are essential in automotive tires, footwear, and seals.

Fibers

Polyester and nylon fibers are widely used in clothing. These polymers help in making wrinkle-free, durable and comfortable clothes.

Biodegradable polymer

Research is focused on developing biodegradable polymers from renewable sources to reduce environmental impact. These include polylactic acid (PLA) and polycaprolactone (PCL) derived from cornstarch.

Biomedical applications

Polymers make significant contributions to the medical field, from biocompatible materials for implants and prosthetics to drug delivery systems using polymer-based carriers.

Environmental impact

The environmental impact of polymers, especially plastics, has attracted serious attention. Although polymers have revolutionized many industries, the challenge lies in their disposal and recycling. Much research is directed towards developing sustainable polymers and increasing the recyclability of existing polymers.

Conclusion

Polymer chemistry is a dynamic and essential part of modern chemistry and materials science. It involves the study of complex macromolecules that are fundamental to countless applications in everyday life and advanced technologies. From plastics to biotechnology, the study of polymers covers a vast and diverse field that includes ongoing research to enhance their properties and reduce their environmental footprint.


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Polymer chemistry

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