Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Introduction to Polymer Chemistry

11,141 views

Published on

Discussing about the fundamental principles of polymer chemistry emphasising on the type of reactions for making polymers.

Published in: Science, Technology, Business
  • Hello! Get Your Professional Job-Winning Resume Here - Check our website! https://vk.cc/818RFv
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

Introduction to Polymer Chemistry

  1. 1. Organic Chemistry V Introduction to Polymer Chemistry Indra Yudhipratama
  2. 2. Outline  Defining the terms in polymer  Type of polymers  Polymer synthesis (Polymerisation) and the properties of its product  Addition polymerisation  Polyalkenes  Condensation polymerisation  Polyesters  Polyamides  Enhancing the polymers
  3. 3. Introduction  Polymers in daily life  All of those are synthetic polymers.  Mother nature also produces polymers.
  4. 4. Defining Polymer  Polymers  Poly (many) + mer (unit)  Hence polymer is a macromolecule that is built from smaller unit (monomer)  Proteins are built from many amino acids. Proteins are polymers, amino acids are the monomers  A polymer can be built from the same monomer Homopolymer e.g. Poly(tetrafluoroethene)  Also can be built from different monomers Copolymer e.g. ABS (Acrylonitrile-Butadiene-Styrene)
  5. 5. Type of Polymers Poly(tetrafluoroethene) ABS
  6. 6. Polymerisation  Addition polymerisation  Involving radicals chemistry  Three main steps:  Initiation  An initiator is required to start reaction  Propagation  The chain is propagated to form a long chain  Termination  Reacts with another radical species to stop the reaction
  7. 7. Addition Polymerisation  E.g. Synthesis of Poly(chloroethene) or PVC  Initiation step  Propagation step  Termination step
  8. 8. Addition Polymerisation  The product of addition polymerisation  From alkene alkane, hence stronger in structure.  More rigid/solid structure  The products could have different arrangement:  Regular structure provides rigid, tough, heat resistant polymers. Known as Isotactic  Commonly used for food containers, hospital equipments.
  9. 9. Addition Polymerisation  The product could have different arrangement:  Irregular structure provides more flexible and softer polymers. Known as atactic.  Used as sealants and coatings.  Third type, the functional group alternates between one side and others, known as syndiotactic. This also has regular structure.
  10. 10. Condensation Polymerisation  Producing small molecules as side products.  Commonly water is the small molecules, hence the process known as condensation.  Polyester formation  Difunctional groups are required to form condensation polymers.  Dicarboxylic acids with diols to form polyesters
  11. 11. Polyesters Polyesters in daily life  Poly(ethylene terephtalate) or known as PET.  The monomers are phtalic acid and ethane-1,2-diol.  A rigid structure due to benzene rings.  Used as plastic bottle
  12. 12. Polyamides  Has amide linkage, occur in nature e.g. proteins.  Formed from amino acids  Synthesised in laboratory from diacyl chlorides and diamines  Problem in synthesis with dicarboxylic acids and diamines
  13. 13. Polyamides  Polyamides in daily life  Nylon  Two types of nylon:  Nylon-6  Synthesised from caprolactam
  14. 14. Polyamides  Two types of nylon:  Nylon-6,6  Synthesised from hexane-1,6-dioic acid and 1,6-diaminohexane  Long alkyl chain gives the flexibility of nylon.  Strong structure of polyamides due to hydrogen bonding and amide bonds  No strong hydrogen bonding in polyesters
  15. 15. Enhancing the Polymers’ Properties  Some polymers are synthesised to meet the market requirements.  Properties of polymers determine its function on the market  Example: Hardness, hydrophilicity  Changing the monomers would change the properties of polymers  Some methods to change the hardness of the polymers:  Using cross-linker  Shortening the monomer chain  Using the aromatic functional group
  16. 16. Enhancing the Polymers’ Properties  Forming crosslink  Natural rubber (rubber band) vs Tyres  Both of them are poly(isoprene)  Tyres manufacturing using sulphur as cross-linker  Vulcanisation process  Bind different polymer chains covalently
  17. 17. Enhancing the Polymers  Vulcanisation process  Sulphur as cross-linker  The covalent bonds of sulphur keeps the shape
  18. 18. Enhancing the Polymers  Forming crosslink  Manipulating the monomers  Difunctional monomers are used  Case of contact lenses  Can be polymerised at both ends  Forming polymer networks  hydrogels
  19. 19. Enhancing the Polymers  Shortening the monomers  Case of pacemaker (polyurethanes)  Polyurethanes are copolymer  Consists of different monomers  Shorter chain (blue) gives the rigidity while the longer chain (red) gives the flexibility over the pacemaker  The flexibility over sp3 carbon chain (free rotation)
  20. 20. Enhancing the Polymers  Using aromatic functional group  Case of Nylon vs Kevlar  The planar structure of benzene ring causes the polymer can be packed more closely.  Increase rigidity of the polymer
  21. 21. Inorganic Polymers  Non-carbon based polymers can also be synthesised  Silicone  Si-based polymers  PDMS Poly(dimethylsiloxane)  Hydrophobic liquid polymer with highly flexible chains  Widely used in shampoo formulation  Known as dimethicone
  22. 22. Inorganic Polymers  Silicone hybrid  Used in contact lenses  Combined with carbon-based polymers

×