polymer 1

• Monomer

  The individual small molecule from which a polymer is formed

  
• Polymer


  Made up of many small molecules (monomer) which have combined to form a single long or large molecule

  
• Polymerization


  The process by which the monomer molecules are linked to form a big polymer molecule

  
• Degree of Polymerization


  Number of repeat units that decides the size of the polymer molecule
• The word "Polymer" is derived from two Greek words, 'Poly' that means many (numerous) and 'Mer' which means units. In basic terms, a polymer is a long-chain molecule that is composed of a large number of repeating units of identical structure

  
• Those monomers can be simple — just an atom or two or three — or they might be complicated ring-shaped structures containing a dozen or more atoms

  
• Classification of Polymers


  • Based on the Origin
  • Based on backbone Chain
  • Based on the property on heating
  • Based on its form and usage

  
• Natural polymer


  Polymers which occur in nature and are existing in natural sources like plants and animals
• Natural polymers


  • Cotton
  • Silk
  • Wool
  • Rubber
• Synthetic polymer


  Polymers which humans can artificially create/synthesize in a lab
• Synthetic polymers


  • Polyethylene
  • Nylon
• Semi-Synthetic polymers


  Polymers obtained by making modification in natural polymers artificially in a lab
• Semi-Synthetic polymers


  • Vulcanized Rubber
  • Cellulose acetate (rayon)
• Linear polymers


  Polymers with a long straight chain of identical links connected to each other
• Branch chain polymers


  Polymers with a long straight chain with some branched chains of different lengths
• Crosslinked or Network polymers


  Polymers where monomers are linked together to form a three-dimensional network
• Crosslinked or Network polymers

  • Bakelite
  • Melamine
• Addition polymers


  Polymers formed by the repeated addition of monomer molecules
• Condensation polymers


  Polymers formed by the combination of monomers, with the elimination of small molecules like water, alcohol etc.
• Intramolecular forces


  Forces that hold atoms together within a molecule
• Intermolecular forces


  Forces that attract polymer molecules towards each other
• The properties exhibited by solid materials like polymers depend largely on the strength of the forces between these molecules
• Elastomers


  Rubber-like solid polymers, that are elastic in nature
• Thermoplastics


  Long-chain polymers where inter-molecules forces (Van der Waal's forces) hold the polymer chains together
• Thermoplastics


  • Polystyrene
  • PVC
• Thermosetting


  Polymers which are semi-fluid in nature with low molecular masses and form a three-dimensional structure on the application of heat
• Fibres


  Polymers which are thread like in nature, and can easily be woven
• Biopolymers


  Polymers which are obtained from living organisms and are biodegradable
• Biopolymers


  • Carbohydrates
  • Proteins
• Reaction of olefin polymer

  1. Ethylene to Polyethylene

  2. Propylene to Polypropylene

  3. Styrene to Polystyrene

  4. Vinyl Chloride to Poly(vinyl chloride)

  5. Tetrafluoroethylene to Poly(tetrafluoroethylene): Teflon

  
• Reaction of Natural Polymers


  1. Isoprene to Polyisoprene: Natural rubber

  2. β-D-glucose to Poly(β-D-glycoside): cellulose

  3. Amino Acid to Polyamino acid: protein

  4. Nucleotide to oligonucleic acid: DNA

  
• Reaction of Polyesters, Amides, and Urethanes

  1. Terephthalic acid and Ethylene glycol to Poly(ethylene terephthalate)

  2. Adipic Acid and 1,6-Diaminohexane to Nylon 6,6

  3. Terephthalic acid and 1,4-Diamino benzene to Kevlar

  4. Ethylene glycol and 4,4-diisocyantophenylmethane to Spandex

  
• Polymer are made up of many small molecules (monomer) which have combined to form a single long or large molecule

  
• Polymerization is a process by which the monomer molecules are linked to form a big polymer molecule

  
• Number of repeat units that decides the size of the polymer molecule is denoted as the degree of Polymerization

  
• Steps in chain polymerization

  • Initiation
  • Propagation
  • Termination
• Chain polymerization is characterized by a self-addition of the monomer molecules, to each other, very rapidly through a chain reaction
• The initiator is a source of any chemical species that reacts with a monomer to form an intermediate compound capable of linking successively with a large number of monomers into a polymeric compound

  
• The functionality of initiators depends on the presence of functional end groups such as hydroxyl and carbonyl, or azo and perester bonds which undergo dissociation to alkyl, alkoxy or acyloxy radicals under the influence of temperature or irradiation

  
• Monomers capable of undergoing chain polymerization reaction

  • Alkenes
  • Vinyl compounds
  • Acrylates
  • Methacrylates
  • Styrene
  • Vinyl chloride
  • Tetrafluoroethylene