Materials and Polymer Chemistry

Nanomaterials are chemical substances or materials in which at least one-dimension measures less than 100nm.These materials are of high importance nowadays in most fields such as Medicine, Chemotherapy, Drug delivery, Manufacturing processes, Paints, etc., because of their novel characteristics like increased strength, Chemical reactivity or conductivity. Nanomaterials can occur naturally and can also be artificially made. Ultrafine particles are those naturally occurring nanomaterials that results as by-products of combustion processes. Some of the ultrafine particles are,Volcanic ash,Soot from forest fires,Welding,Diesel engines.

Artificially made nanomaterials are those which are engineered for an intention with the physio-chemical properties for a specific purpose or function. The methods of preparing nanomaterials also differ based on the purpose. Nanotechnology is highly used in detecting devices as their nanostructure with greater surface area per weight allows the electrical properties of the detecting elements to be changed easily. Nanotechnology controls matter at the atomic and molecular scale. Several applications of nanomaterials are as follows.

• Bacteria sensors
• To trap oil spills
• Rapid disease diagnostics
• Nanotube polymer to speed up replacement of bones

Nanoparticles are used extensively in catalysis to boost up chemical reactions. Polymer based nanomaterials have high significance in Analytical Chemistry and research as they can amplify the sensitivity, and improve the stability of traditional materials and methods. Nanomaterials are one of the best cleaning agent for the environment. They are used in water purification processes, detect chemical and biological agents in the soil and air, desalination. Materials can be made to be stronger, lighter, more durable, more reactive, better electrical conductors using nanotechnology.

A domain of Chemistry which focuses on the chemical systems that are made up of molecules and deals with the weaker non-covalent bond between molecules. It is a sub-group of physical organic chemistry wherein the understanding of the physics behind non-covalent bonding is on focus. The study of non-covalent interactions is important to understand many biological processes like cell structure formation which depends upon these bonds. Biological systems are the basis of Supramolecular Chemistry. The forces which come under non-covalent interactions also known as secondary interactions between molecules are hydrogen bonding, metal co-ordination, hydrophobic forces, Van der Waals forces, Pi-Pi interactions and electrostatic forces. Host-Guest Chemistry and Self Assembly are the two broad categories of Supramolecular Chemistry. Supramolecular Chemistry demonstrates the following important concepts which are,

• Folding
• Molecular recognition
• Mechanically-interlocked molecular architectures
• Dynamic Covalent Chemistry

Supramolecular Chemistry is often referred as “The Chemistry beyond the molecule” as it revolves around the intermolecular attractions which covers the structure and functions of the entities formed by the association of two or more chemical species. Molecular recognition is achieved by the non-covalent bonds that exists between the molecules which aids in specific binding involved in several biological systems like Enzyme and Ligand binding, molecular transport, genetic information and processing, protein assembly. Host-guest chemistry works on the principle of lock and key mechanism wherein a larger molecule behaves as a host to which the smaller molecule binds to. Self-assembly is the interaction between molecules via hydrogen bonds when there is no difference in size. DNA is one of the best example of Supramolecular Chemistry. The molecules store information in the form of structural peculiarities. Not only the combined action of molecules, but also the combined action of the characteristic parts of the same molecule is called “Supramolecular”. Major applications of Supramolecular Chemistry include the analysis of chemical compounds which are medically, technically and environmentally important. Supramolecular Chemistry attracts not only the Chemists, but also the Environmental Scientists, Biologists, Physicians, Bio-Chemists, Crystallographers. The complex biological molecules which are difficult to study can be easily isolated and quantified with the help of Supramolecular Chemistry

Sustainable Chemistry is an area of Chemistry and Chemical Engineering which aims in improving the efficiency of products and processes that are friendly to the environment by minimizing the use and generation of hazardous substances. Sustainable Chemistry is also known as “Green Chemistry”. Environmental Chemistry and Sustainable Chemistry are related; however, they differ in the fact that the former explains the effects of polluting chemicals in nature whereas the latter explains the technological approaches to prevent pollution and to reduce the consumption of non-renewable resources. Sustainable Chemistry involves the design, manufacture and use of efficient, effective, safe and more environmentally amiable chemical products and processes. Several principles are adopted to reduce the environmental and health impacts of chemical production and for the development of green chemistry technologies. 

Sustainable Chemistry eliminates the risk of chemicals at the design stage itself. The elimination of risks in the beginning of chemical design process have a lot of advantages over our health and environment throughout the design, production, use and disposal processes. The use of alternative and renewable materials including the use of agricultural waste or biomass and non-food-related bioproducts is the major principle of Sustainable Chemistry. Other principles focus on prevention of waste, less hazardous chemical syntheses, and designing safer chemicals including safer solvents. The design of chemical products to safely degrade in the environment, efficiency and simplicity in chemical processes are the other areas of focus in Sustainable Chemistry. A transformation to green chemistry techniques would result in safer workplaces for industry workers, greatly reduced risks to fence line communities and safer products for consumers. The efficiency of Sustainable Chemistry allows companies to consume less raw materials and energy as well as save money on waste disposal. Consumers and business purchasing departments can promote green chemistry by demanding safer, non-toxic products from manufacturers. This will help give a competitive advantage to everyone thereby creating a sustainable environment.

Monomer is a single, smallest molecule of a chemical substance which binds chemically or supramolecularly with other molecules to form a polymer in a process called Polymerization. A multi protein complex is made up of a monomeric protein. Monomer is the basic element of the building block of an organic substance. The monomers are connected through covalent chemical bonding, which are formed by the sharing of electrons between atoms. The monomers amino acids, nucleotides, monosaccharides and fatty acids form the four macromolecules Carbohydrates, Proteins, Lipids, and nucleic acids that form up the biological system, each of which have a specific function in growth and development. The monomers of DNA are called "Nucleotides”. These nucleotides are made up of a 5-carbon sugar(deoxyribose), a phosphate group and a nitrogenous base bound to the sugar. 

The monomers according to their combination are known as dimer, trimer, tetramer, pentamer, hexamer, heptamer, octamer, nanomer, decamer, dodecamer, eicosamer. Monomers are the molecules which carry out the vital functions needed by the cells. It is essential to understand the monomer, the basic structure of polymer to create or modify or improve the already existing polymers performing various functions.

A dual functionality monomer, Glycidyl Methacrylate (GMA) is of high purity and it is suited for coating and resin applications. The key feature of a monomer is polyfunctionality, which is the capacity to form chemical bonds to at least to two other monomer molecules. The properties such as adhesion, chemical resistance, substrate wetting, improved weathering is responsible for the improved performance of monomers and oligomers which makes them most suitable for use in coatings.  There are some applications which require higher water and oxygen transmission rates without sacrificing basic mechanical or physical properties of the polymer backbone, hydrophilic properties are introduced to the polymer. The property of the monomer is changed and used in optical lenses, membranes, biomedical devices, breathable coatings and other high value-added applications.

A polymer is a large macromolecule made up of single small repeated subunits called monomers in a process called polymerization. Polymers can be natural polymers and synthetic polymers where the former one is the biological compounds like proteins in our body whereas the latter one is the plastics like polystyrenes. Polymers possess a broad range of properties like toughness, viscoelasticity, etc., they play a universal role in everyday life. Polymers are studied in variety of fields like Biophysics, Macromolecular science, Polymer Science which includes Polymer Chemistry and Polymer Physics. The products formed from the linkage of repeating units by covalent bonding is the primary focus of Polymer Science. 

The polymer molecules arranged linearly (unbranched) one after the other forms the “backbone” of a macromolecule. Polymers are usually composed of hydrocarbons, compounds of carbon and hydrogen. Linear polymers when not arranged in a specific order is known as amorphous polymer and those arranged according to a specific order is known as crystalline polymer. The polymers are classified based on many characteristics like their origin, structure, mode of polymerization, molecular forces. Polymerization is the process by which monomers get combined and transformed into polymers. Polymerization is a step by step process which begins with the chain initiation, followed by chain propagation and finally ends with the chain termination step. Copolymers are formed when two different monomers combine to form a polymeric molecule. Polymers are more beneficial as insulating material, materials for gears, etc., They enhance self-lubrication cost savings. Also, noise reduction and weight reduction are achieved by using polymer materials for gears. The disposal of polymers brings certain disadvantages like excess production of carbon dioxide which further adds to global warming, toxic gases are also released. Incineration, land fills and recycling are the best ways to dispose polymers by protecting the environment.  

Polymers also known as plastics are synthetic organic compounds which are malleable and can be molded in the desired form for different purposes. After the usage, disposal of plastics pollutes the environment in different ways. The traditional plastics are not degraded easily because of their long polymer molecules which are too large and too tightly bonded together to be broken apart and assimilated by decomposer organisms. However, biodegradable plastics have molecules that are readily attacked and broken down by microbial organisms. Biodegradable are the substances which are decomposed by bacteria or other biological organisms thereby not polluting the environment. Biodegradable plastics fits to be one of the best alternative of plastics. Biodegradable plastics are made from many natural plants like corn oil, orange peels, starch. These natural plants made into pulp, melted down and poured into molds of different shapes according to the needs and uses. Injection molded and solid are the two forms of biodegradable plastics in which solid form is used as food containers, leaf collection bags and water bottles.

The role of plastics in our daily life is omnipresent. The fact that biodegradable plastics are the products which meets the needs of manufacturers and consumers along with active dilution of environmental risks has attracted most Scientists and Researchers in the plastic industry to continue research on biodegradable plastics. Despite finding new technologies to cut down the environmental pollution caused by plastics, certain awareness on saying “NO” to the excess use of plastics has to be created to save the environment fully. The following four R’s to be borne in mind to curtail the use of plastics: Refuse, Reduce, Reuse, Recycle. Finding an alternative like biodegradable plastic can truncate the effects of plastic in the environment and not fully make the effect to be disappeared on the whole. Therefore, changes in the way we buy, consume and dispose of plastics are just as important as any scientific breakthrough.

The characterization of a polymer is important to improve the performance of the material. A polymer is characterised during synthesis, evaluation, and when the performance of the product has to be improved. The properties such as strength, permeability, thermal stability, and optical properties are considered before choosing a polymer. The characterization of a polymer includes the following,

• Molecular weight distribution
• Molecular structure
• Polymer Morphology
• Thermal properties of polymer
• Mechanical properties of polymer

Polymer characterization helps us to determine whether the polymer is a homo-polymer or copolymer, to know the melting point, chemical filler used, tensile strength and compressibility are also identified by characterizing the polymer.

The process by which monomers are covalently bonded to form a polymer chain or network is known as polymer synthesis or polymerization. The polymers are synthesized differently to influence the physical properties like density, crystallinity, melting point and strength. When a polymer is synthesized, water is released as a by product which is known as “Dehydration synthesis” meaning combined while losing water. Even the human DNA is a result of polymerisation of its monomer nucleotides. Polymers are produced by these two chemical reaction types.

• Condensation polymerization
• Chain growth polymerization

The former synthesis process in which monomers react and give a repeat unit and a smaller molecule water, whereas the latter forms a highly reactive free radical and a molecule with an unpaired electron. For every molecule, their synthesis has to be understood to analyse, make changes and improve them accordingly

The only material which act as matrices for the incorporation of the widest range of ceramics, nanotubes, nanoparticles, as well as a variety of short and continuous fibres, to create new building and structural materials is the “Polymer”. Polycarbonate, nylon, acrylic, polyester, PET are some of the polymeric materials commonly used. Thermosetting polymers, Thermoplastic polymers are some of the types of polymers.

Polymer Chemistry also known as Macromolecular Chemistry is a branch of Chemistry that deals with the properties, processing of macromolecules called polymers. Polymer chemistry also deals with problems related to Medicine, Biology, Biochemistry and Material Science; however, Polymer Chemists focus on synthetic organic polymers due to their commercial importance. Polymer Chemistry is all about analysing and understanding how the monomers combine to create useful materials with the desired specific characteristics by manipulating their molecular structure, the composition, and applying chemical and processing techniques that can affect the properties of the final product.

Polymer Science is an interdisciplinary area which can be considered as a sub-discipline of Material Science. It comprises of Chemical, Physical, Engineering, Processing and Theoretical aspects. As the importance of Polymer Science is increasing in our everyday life, it is important to understand the structure/property relationships of polymeric materials. The knowledge of Polymer Science is utilized to save energy by improving renewable energy through various technologies.

Polymers are designed at the molecular level by the engineers to understand them better using computational methods. Apart from the natural polymers in the biological environment, most polymers are synthesized artificially with the knowledge of polymer design. The strength of the polymer material is imparted to it through a series of steps which are involved in the design of a polymer. Different patterns and tools are available to design a polymer.

Polymer Engineering is a sub-branch of Material Science where the engineering of new products is in foreground. Many challenges have to be faced by a Polymer Engineer like the maintenance of viscosity, temperature, pumpability, etc. Polymer Engineering has now engulfed the areas of research and made the contemporary scenario to be called as “Polymer Age”.

“Polymeric biomolecules” or the Biopolymers are polymers produced by living organisms. Polynucleotides, Nucleotides and Polypeptides are the three main classes of polymers. Biopolymers contain similar sequences, same number of monomers and similar molecular mass. The two broad classes of Polymers, namely Biopolymers and Synthetic Polymers differ in their structure wherein the Biopolymers have a well-defined structure and the Synthetic Polymers are arranged in a random order with a simple structure. 

Polymers are used in different day to day applications like domestic plastics, pipes, bags, wires, etc., based on their strength, withstanding pressure and various other properties. The real understanding of the polymers, their properties and the process is much more important so as to choose the most suitable material for its purpose. The proper choice of material according to the purpose predicts the potential, performance and behavior in the real world.

Smart polymers are high performance polymers which are sensitive to many factors like temperature, humidity, pH, light intensity, magnetic fields, etc. They respond to the stimuli and they change colors, shape, become conductive or permeable to water. Therefore, these polymers are called “Stimuli-Responsive Polymers”. These highly responsive smart polymers are used in drug delivery, self-adaptive wound dressing, and many other medical and general applications.  

The fundamental impact of Material Chemistry in Regenerative Medicines provides many upcoming platforms in tissue engineering. Different methodologies are adopted to replicate morphologies and architecture, of mineralized tissues like dentine, enamel and bone that require regeneration. Plastics and polymers are now developed with vascular network which are filled with regenerative agents acts similar to biological healing whenever damage occurs.

The advancements and innovations using the polymers is achieved in the field of medicine to a greater extent. Polymer scaffolds that help in healing damaged tissues, artificial polymer skin, tumor killer, polymer lotion, artificial cornea, antibacterial hydrogels, elastic medical devices are the important recent innovations of polymer technology in the field of medicine. Flexible robots which helps the Scientists and Doctors are designed used polymers. With the self-repairing mechanism, polymers are now employed in repairing scratches in cars that require less materials to repair instead of replacing the entire part or resurfacing the entire area.

The future of Polymer Chemistry shines bright as there is a welcoming demand for polymers. To be specific, biopolymers will be of high interest because of its ability to be one of the best alternative for conventional plastics that too with the goal of protecting the environment. The Chemical Industries are capable of producing high quality polymers with distinct standards by utilizing the technological developments made. The current innovations and the research that has been initiated in Polymer Chemistry and Material Science gives an assured future to the polymers in almost all aspects of our everyday life.