Inorganic Polymers Quiz

Polymer Classification

• Polymers are broadly classified by their synthesis method, structure, and properties.
• Plastics, rubbers (elastomers), and fibers are common polymer types.
• Plastics (also known as thermoplastics) soften with heat and can be reshaped or recycled..
• Elastomers are polymers that exhibit rubber-like properties, high strength and stretching.
• Fibers have a high length-to-diameter ratio, and high tensile strength.
• Liquid resins dissolve or suspend in other liquids.

Polymer Types

• Addition polymers are formed by combining monomers without losing any small by-products.
• Condensation polymers are formed by combining monomers with the release of small by-products (e.g., water).
• Examples of addition polymers include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and polystyrene (PS).
• Examples of condensation polymers include Nylon (6,6), polyester (PET), and phenol-formaldehyde.

Polymer Properties

• High strength: ability to withstand high loads.
• Resilience: ability to return to its original shape after deformation.
• Transparency: ability to transmit light.
• Low cost: comparatively inexpensive to produce.

Polymer Structure and Arrangement

• Monomers are the building blocks of polymers.
• Polymers can vary in structure as linear, branched, cross-linked, or network.
• Linear polymers have long, continuous chains with no branches
• Branched polymers have side chains or branches attached to the main chain.
• Cross-linked polymers have strong chemical bonds between the main chains making rigid structures.
• Network polymers have a complex 3D network structure that are hard, rigid and brittle
• Tacticity: the arrangement of substituent groups along the polymer chain.
• Tacticity relates to physical properties.

Polymer Origin and Classification

• Polymers can be natural or synthetic
• Natural polymers are derived from natural sources (e.g., cellulose, proteins, natural rubber).
• Synthetic polymers are created by chemical reactions in laboratories from monomers (e.g., polyethylene, nylon).
• Semisynthetic polymers are chemically modified natural polymers.

Polymer Classification Based on Chain Configuration

• Monomer orientation and tacticity affect polymer properties.
• Head-to-tail and head-to-head monomer linkages affects bonding effects.
• Geometric isomerism (cis-trans) is involved in some polymer structures and affects properties.
• Tacticity (isotactic, syndiotactic, atactic) describes the arrangement of side groups on the polymer chain, affecting properties like crystallinity.

Polymerization Reaction Product

• Addition and Condensation reactions are fundamental processes in polymer synthesis.

Classification Based on Thermal Behavior

• Thermoplastics can be melted and reshaped repeatedly, and are typically amorphous or semicrystalline.
• Thermosets cannot be melted and reshaped after initial curing, and are usually crosslinked networks.

Some Important Polymers

• Polyethylene (PE): Low-density and High-density variations, used in packaging, films, bottles, etc.
• Polypropylene (PP): Used in packaging, fibers, and automotive parts.
• Polyvinyl Chloride (PVC): Used in pipes, flooring, and window frames.
• Polystyrene (PS): Used in packaging, insulation, and containers.
• Nylon: Used in fibers, fabrics, and engineering applications.
• Polyester (PET): Used in textiles, fibers, packaging, and bottles.

Copolymers

• Copolymers are polymers formed from two or more different monomers, with sequential distributions obeying known statistical laws (Random, Alternating or Block).
• Statistical copolymers: monomers arranged randomly.
• Alternating copolymers: monomers arranged in an alternating pattern
• Block copolymers: monomers arranged in long blocks.

Electroluminescent Polymers

• Electroluminescent polymers emit light when an electrical current is applied.
• These polymers are used in various applications requiring bright, high-performance light displays.
• Their construction and working involves layers of conductive and non-conductive materials.

Conducting Polymers

• Conducting polymers are those which conduct electricity due to delocalization of π electrons.
• Polyacetylene, Polythiophene, and Polyaniline are examples of conducting polymers and have various applications in electronics and other fields.

Additional Points

• Chain length significantly affects the properties of polymers (e.g., melting point, strength).
• Different types of polymers (e.g., commodity and engineering) are suited for different applications.