Basic polymer properties

Question 1

Macromolecules

Answer 1

Molecules made of a large number of atoms

Question 2

Polymers

Answer 2

Substances of a high molecular weight with repeating monomer units

Question 3

Pharmaceutical applications of polymers

Answer 3

Drugs
Adhesives 
Hydrogels
Suspending agents
Film coatings
Packaging
Giving sets
Tablet matrices

Question 4

If the polymer is polydisperse,

Answer 4

It contains a range of molecular weights

Question 5

Gel Electrophoresis

Answer 5

Separates polymers using charge + molecular weight

Question 6

What polymer structure is simeticone

Answer 6

Homopolymer

Question 7

Chemical reactivity of polymer depends on

Answer 7

Monomers

Question 8

Physical properties of polymer depends on

Answer 8

Arrangement of monomers

How the polymer chains interact with each other and/or the environment

Question 9

What polymers do not have an exact molecular weight + why

Answer 9

Synthetic + naturally occurring polymers

- because they are polydisperse.

Question 10

Mn

Answer 10

Number average molecular weight

Question 11

Mw

Answer 11

Weight average molecular weight

Question 12

Degree of polydispersity

Answer 12

Mw / Mn

Question 13

What can water-soluble polymers do

Answer 13

• increase viscosity of solvent
• swell / change shape
• adsorb at surfaces
  which makes them useful as suspending agents (carbomer, acacia)

Question 14

Use for insoluble polymers

Answer 14

Form thin films for use in tablet coating, wound dressings, membranes

Question 15

Rate of dissolution of a water-soluble polymer is dependent on…

Answer 15

molecular weight

• high molecular weight means stronger forces keeping chains together
• therefore more energy needed to break them

Question 16

Velocity of penetration

Answer 16

(of a solvent into the bulk polymer)

S = kM^-A

Question 17

What are constants in velocity of penetration

Answer 17

k + A

Question 18

What does M mean in velocity of penetration

Answer 18

Polymer molecular weight

Question 19

What does a negative A mean in velocity of penetration

Answer 19

S (velocity of penetration) is inversely proportional to the molecular weight

Question 20

Pharmaceutical uses of water-soluble polymer

Answer 20

Wound-dressings
Contact lenses
Bulk laxatives
Nappies
Vehicles for drug delivery

Question 21

Crosslinked water-soluble polymers can be come ____

Answer 21

Swollen

- large quantities of water can be retained leading to increase volume

Question 22

How can polymer gels form

Answer 22

Swelling of a highly cross-linked polymer

Making dissolved polymer less soluble

Question 23

Relation between viscosity and concentraion

Answer 23

Viscosity increases with polymer concentration

Question 24

Polymer gels will possess a…

Answer 24

critical gelation concentration

• gel cannot be formed below this polymer conc
• depends on molecular weight

Question 25

Classification of Gels

Answer 25

Type 1 = irreversible systems contact lenses) | Type 2 = heat-reversible (gelatin / agar)

Question 26

A greater solubility parameter...

Answer 26

A more polar substance

Question 27

Increasing cross-linking speeds of water-soluble polymer speeds up...

Answer 27

Dissolution

Question 28

What solvent has an expanded open structure

Answer 28

Good solvent

Question 29

What solvent has ideal conditions

Answer 29

Theta solvent

Question 30

Poor Solvent

Answer 30

High polymer-polymer interaction = compact cotacted structure

Question 31

Example of a good solvent

Answer 31

Water

Question 32

example of a poor solvent

Answer 32

THF = tetrahydrofuran

Question 33

How can charge of a polymer affect molecular shape

Answer 33

``` Neutral = polymer contracted, low viscosity Ionised = groups repel; expanded structure; increased viscosity ```

Question 34

What structure would the polymer sodium alginate be in a good solvent

Answer 34

Expanded open structure | e.g. water

Question 35

What would the polymer sodium alginate structure be in a poor solvent

Answer 35

Contracted, compact structure

Question 36

Solubility parameter

Answer 36

s = ( △Hv - RT / V ) ^1/2 Measure of cohesion between like molecules - Used to predict polymer swelling

Question 37

v in solubility parameter

Answer 37

Molar volume

Question 38

T in solubility parameter

Answer 38

Absolute temperature

Question 39

R in solubility parameter

Answer 39

Gas constant

Question 40

△Hv in solubility parameter

Answer 40

molar enthalpy (heat) of vaporisation

Question 41

The greater the solubility parameter...

Answer 41

more polar the substance

Question 42

What solvent has the highest solubility parameter

Answer 42

Water

Question 43

Polymer at Low concentration

Answer 43

Isolated polymer chains | Shape + volume determined by polymer-solvent + intra-polymer interactions

Question 44

Mark Houwick

Answer 44

n=KM^a n = intrinsic viscosity K + a = constants M = molecular weight

Question 45

a in the mark houwick equation a reflection of

Answer 45

Shape of the polymer

Question 46

Shape of polymer with an a value of 1.8

Answer 46

Rod

Question 47

Shape of polymer with an a value of 0.5-0.8

Answer 47

Random coils

Question 48

Shape of polymer with an a value of 0

Answer 48

Spheres

Question 49

Light scattering techniques

Answer 49

measure polymer molecular weight + hydrodynamic radius

Question 50

Viscosity Rheological Flow techniques

Answer 50

Examine flow properties + polymer shape

Question 51

Analytical ultracentrifugation

Answer 51

Separates polymers according to molecular weight

Question 52

Gel electrophoresis

Answer 52

Separates polymers according to charge + molecular weight

Question 53

Nuclear magnetic resonance

Answer 53

Conformation in solvent, structure

Question 54

Differential scanning calorimetry

Answer 54

Used to examine interactions between polymer chains

Question 55

Gel permeation chromatography

Answer 55

Separate polymers according to molecular weight