Tae Lin Pak Choi - 1 Flashcards
Definition of Polymer and macromolecule
- Monomer linked by covalent bond to form polymer
- mer : basic repeat unit (from Greek ‘meros’)
- Polymer: high molecular weight molecule normally above mw: 10,000
Property of polymers
goods/bads
- Goods: light, tough, easy coloring, low price. Stable against air and moisture as well as acid and base. heat and electric insulator
- Bads: weak against heat and give toxic compounds when burnt, too stable??
Usage of polymers
just some of them
- Clothing: nylon, polyester
- Plastics: PET, Plexiglass
- Rubbers: tires, elastomers
From classical usage to modern/hi-tech materials –> broad usage
Classification of polymers
diagram
- Polymers
- Polymer Science
- Poly. Physics
- Theory, Statistical Mechanics
- Analytical tools
- Polymer Chem.
- Synthesis
- Chemical Property & Nanostructures
- Synthesis
- Poly. Physics
- Poly. Engineering
- Industrial application
- Process
- Blending
- Polymer composites
- Mechanical property
- Biomedical & Electronics
- Energy storage
- Process
- Industrial application
- Polymer Science
Monomers and Polymers
Change in property between monomer and polymer
polymerization, properties, bond formation
- Polymerization put togheter by catalyst or heat
- Property can be totally different from that of monomers
- Bond formation during polymerization (at least 10 kDa) –> organic chemistry
What is Chemistry?
The study of properties of matter (materials) and their changes
Then what is Organic compounds (matter)?
Compounds containing carbon, hydrogen and others
Organic compounds in our lives: clothes, food, medicine, new drugs (antibiotics and anti-cancer), fertilizers, pesticides, oil, soap, plastics, building blocks of life (fat, sugars, proteins, nucleic acids) and many others
hen what is chemical changes in Org. Chem?
Change in electrons
Basic organic chemistry
Types of bonds
Which looks more stronger or more stable?
sigma (σ) bonds = single bonds
pi (π) bonds = one extra bonds
In pi bonds there is less overlapping, quindi sono meno forti and also less stable –> more reactive
Movement of electrons
Types of bond cleavage and mechanism
Heterolytic bond cleavage: A-B –> A+ + B-
Homolytic bond cleavage. A-B –> A. + B.
Movement of electrons
- Electrons pushing
Flow of electrons pair from its point of origin to destination
Electrophiles (poor in e-) and Nucleophiles (rich in e-)
Fundamental factors that govern the reactions
Energetic factor:
* thermodynamics
* bond dissociation energy
* electronegativity,
* stability,
* pK a
Electronic effect
* Element effect
* Inductive effects
* Resonance effects
* Hybridization effects
Steric effect
Thermodynamics: driving force of rxns
What does exoergonic mean?
How to push the reactions?
Endothermic, exothermic
ΔG = ΔH - TΔS
(-) ΔG, the process is exergonic, be spontaneous and favor the products
Push the reaction using catalyst: gives higher driving force making reactant more stable
Acid-base reaction: pK a
Ka is the equilibrium constant for the reaction between an acid and WATER:
* HA + H₂O ⇌ A⁻ + H₃O⁺
* K_a = [H₃O⁺][A⁻] / [HA]
Ka values range from 10^-50 to 10^10
pK A is a measure of intrinsic stability of the anion, A : teaches us key concept of how organic chemistry works
How is the charge stabilized on volume?
positive or negative charge is stabilized when it is spread over a large volume (of the atom)
