Polymers 3

Question 1

what are the 3 stages of dissolution

Answer 1

diffusion of solvent molecules into polymer

swollen gel

dissolution of gel

Question 2

what happens if a polymer is crosslinked

Answer 2

there is no dissolution

Question 3

when does solubility occur

Answer 3

free energy of mixing is negative

Question 4

when do we know when free energy of mixing is negative

Answer 4

gibbs free energy is negative

Question 5

what is the equation gibbs free energy

Answer 5

enthalpy of mixing
entropy of mixing
temperature

Gibbs free energy = enthalpy of mixing - (Temperature X Entropy of mixing)

Question 6

what factors affect the solubility of polymers

Answer 6

polymer solvent interactions

presence of cross links or strong intramolecular interactions

molecular weight of macromolecules

temperature

Question 7

what do strong polymer solvent interactions favour

Answer 7

solubility and has good affinity

Question 8

what rule do most polymers follow

Answer 8

polar polymers are soluble in polar solvents

non polar polymer in non polar solvents

Question 9

do covalently cross linked polymers dissolve

Answer 9

no

Question 10

how does crystallinity affect solubility

Answer 10

crystallinity and strong intramolecular interaction act as physical cross links and are unfavourable for polymers solubility