Polymer Primer

Question 1

Define polymer

Answer 1

Large molecule constructed from many smaller structural units called monomers covalently bonded together

Question 2

monomer

Answer 2

simple molecule from which polymer is synthesized

Question 3

repeat unit

Answer 3

structural unit that is repeated in the chain

Question 4

homopolymer

Answer 4

polymer in which all the repeat units are identical; only one monomer involved in synthesis

Question 5

copolymer

Answer 5

polymers composed of more than one type of repeat unit; 2 or more monomers are involved in synthesis

Question 6

polydisperse

Answer 6

polymers commonly made up of a molecules having a distribution of molecular sizes

Question 7

amorphous

Answer 7

polymer chains making up the solid mass are completely randomly arranged

Question 8

semicrystalline

Answer 8

solid mass is composed of randomly arranged chains in some areas and chains arranged in orderly, but short-range fashion in other areas

Question 9

free volume

Answer 9

= space between polymer chains = drug and water molecules can diffuse through

Question 10

amorphous polymers have _____ free volume which means ____ solubility

Answer 10

high; high

Question 11

T or F: amorphous polymer possess both glass transition temperature (Tg) and melting point (Tm)

Answer 11

False, amorphous polymers only have Tg

Question 12

semicrystalline polymers have a melting point because

Answer 12

they possess crystalline regions

Question 13

Below Tg, polymer is

Answer 13

brittle

Question 14

Above Tg, polymer is

Answer 14

softer and more rubbery due to thermal energy allowing chains to move

Question 15

Crystalline regions in a semicrystalline polymer have very ___ free volume

Answer 15

low free volume because of close and regular packing of the chains

Question 16

PLA polymers are more _____ than PGA polymers because of the additional methyl group

Answer 16

hydrophobic

Question 17

Which polymer is made from renewable resources like corn?

Answer 17

PLA

Question 18

Which polymer is semicrystalline?

Answer 18

PGA

Question 19

Viscosity measurements are proportional to MW. Why?

Answer 19

The higher the MW, the longer the polymer chains, the more viscous

Question 20

example of non-degradable polymeric biomaterial for drug delivery

Answer 20

EVA - ethylene-vinyl acetate copolymer

Question 21

EVA is amorphous or semicrystalline?

Answer 21

Amorphous

Question 22

Examples of use of EVA

Answer 22

as polymer membranes in transdermal patches or structural support material for contraceptive devices