D5: Basic polymer properties 1 Flashcards
Define a macromolecule
molecules composed of a large number of atoms
Define a polymer
substance of high molecular weight consisting of repeating monomer unit
What are the 5 polymer structures?
1) homopolymer
2) alternating copolymer
3) random copolymer
4) block copolymer
5) graft copolymer
What is the use of simeticone?
defoaming agent used to relieve trapped wind/ bloating
What is the IUPAC name of simeticone?
polydimethylsiloxane
What polymer structure does simeticone take?
homopolymer
What depends on chemical reactivity of a polymer?
largely depends on the monomeric unit
What is the physical properties of polymers dependent on?
arrangement of monomers
how the polymer chains react with each other and/or environment
What is meant by polydisperse?
most synthetic and naturally occurring polymers don’t have an exact molecular weight
How is degree of polydispersity measured?
=Mw/Mn
What are the 7 techniques to characterise polymers?
1) light scattering techniques
2) viscosity and rheological techniques
3) analytical ultracentrifugation
4) gel electrophoresis
5) Nuclear magnetic resonance
6) differential scanning calorimetry DSC
7) gel permeation chromatography
What does light scattering techniques measure?
polymer molecular weight and hydrodynamic radius
What does viscosity & rheological techniques examine?
flow properties & polymer shape
How does analytical ultracentrifugation work?
separates polymers according to molecular weights
How does gel electrophoresis work?
separates polymers according to charge and molecular weight