10/2 Polymer Synthesis and Characterization 9:46 - 9:50 4 minutes

Implanted polymers: water soluble / biodegradable

How to make polymers:

  • select monomer + purification: distillation

  • polymerization: monomers —> polymers

  • purification: separate everything into pure polymer

  • blending:

  • casting

  • post processing

Monomer Distillation:

  • add inhibitors to prevent polymerization (chemicals)

  • natural tendency to polymerize

  • have to remove inhibitor

  • cold area: condenses and collects

    • solution of pure monomer on left side

    • impurities are on other side

Polymerization:

Main classes of Polymerization:

  • Step Growth

    • co monomer system (2, A + B)

    • Add catalyst to cause A and B to bind (dimeryze)

    • Dimer —> Trimer = A + B + A or B + A + B

      • Solution full of monomers, dimers, trimers, …

      • More likely for monomer to bind bc there’s more and diffuses faster

      • when not a lot of monomer left, larger ligamer + ligamers = really big polymer

      • Step bc bigger and bigger polymers find

      • Viscous solution (no

      • nviscous to viscous)

      • Can add from both ends

    • Exponentially increases towards end

  • Chain Growth

    • Adding one link at a time and it has to be a monomer

    • (only on growing end)

    • Exponentially increases towards beginning, high molecular weight very quickly, slows down bc no more monomer

  • Living Chain Growth

    • care about cost

Describe the difference ***important

  • draw the kinetics

  • why does the change in kinetics work

Step Polymerization:

  • Acetic Acid + Ethyl Alcohol (ester bond + release water when catalyst add)

    • Not a polymer

    • condensation reaction bc water molecule is released

    • If you add another = symmetry

    • acid + alcohol on both ends = polymer produced

    • can bind with more

    • dimer can bind with more to form polymer chains

    • Polyethylene teraphaeleate (plastic soda bottles, polyester)

      • not biodegradable

PET not biodegradable

2 things for hydrolysis

  • Labile bond

  • water

Common Polymers formed through condensation reactions (slide 10)

  • remember nomenclature

  • write cheat sheet

  • Polyester:

    • Acid + alcohol —> ester

    • when generate new ester (polyester)

      • many different ways to draw it

    • bracket is chemistry,

  • show me untuitive way it’s drawn

  • Polyether:

    • ether generated

  • Polysulfide

    • sulfur instead of oxygen

  • Polycarbonate

  • Polyamide

    • literally any protein

  • Polyurethane

  • Polyurea

  • Polyanhydride

    • labile bonds, easily biodegradable bc hydrolysis

    • google all of these: look at all these examples

      • show derivation that looks similar that throws you off

      • give chemical structure, identify what it is

2 Polymers you have to remember always:

  • PEG (describe what type of polymer —> polyether)

  • Polycapralactone (polyester)

Polycondensation:

  • Liberate a molecule not necessarily water when polymerizing

  • Polyester synthesis

    • liberate HCl or HBr (Acid Halide)

    • Exothermic, gets really hot and releases gas so make sure you have fume hood

  • Polyamide syntehsis

    • Amid bond

    • Liberates water

Nylons:

  • nylon rope trick:

  • Alcohalide: bonds with anything hydrophilic

  • Monomers A and B are not miscible

  • Add together and they form an interface

    • Polyamide film at interface, step growth

    • Tweezers and pll it out, more polymers,

    • You can just wind it out and there is more interface, and more nylon

  • Gaseous hydrochloric acid, bad for your lungs =w=

Polyaddition Reaction:

  • polymer formed but NO elimination

  • glue/epoxy

Chain Growth Polymerization

  • Initiation

    • initiator starts reaction

    • Something like heat makes it so there’s free radicals

    • Unpaired electrons want to be paired

  • Propagation (grows)

    • Unpaired at end

    • Passing unpaired electron down polymer chain so it keeps on adding monomers

  • Chain Transfer (if living)

  • Chain termination

    • Never gonna be happy, unpaired electron find each other again

    • oxygen loves unpaired electrons so it’ll stop reaction

FRP (Free radical polymerization)

  • Prescence of vninyl group (alchine)

  • Pi orbital electrons, sharing with each other, electron rich

  • Slide 17 *** important

  • Styrene

  • Acrylate

  • Methacrylate (+CH3)

  • Acrylamides

  • Methacrylamides

  • Vinyl Ester

  • Vinyl Amides

Number 17 is ***important

Nitrogen?

Methyl group? CH3 or line

Common FRP Polymers

  • draw different structures,

  • polyester, acrolamide, whatever,, polystyrine

  • google bunch of examples of how it’s differently drawn

Living Radical Polymerization (chain growth, living)

  • reaches high molecular weight really quickly

  • Need to add referee (slows everything down)

    • Sits on end, only allows growth in a steady fashion (cap)

    • same rate, precisely define end weight (around same chain length)

    • RAFT polymerization