Lecture 17: Polymers

Question 1

Functions of polymers in pharma products

Answer 1

-controlled delivery
-scaffolds for tissue engineering
-transdermal patches

Question 2

polymer function in oral drug delivery

Answer 2

-coating
-binders
-taste maskers
-protective agents

Question 3

Polymer

Answer 3

-large molecule made of many small repeating units
-macromolecules and plastics

Question 4

macromolecules

Answer 4

-any large molecules
-polymers are a subset (repeating units)

Question 5

Plastics

Answer 5

-can be molded, cast, extruded, draen, thermoform, laminated into product

Question 6

Polymer basics

Answer 6

-natural vs synthetics
-name
-structure
-synthesis
-molecular weight
-crystalline vs amorphous
-glass transition temp
-mech properites
-applications

Question 7

Nitrocellulose (1845)

Answer 7

-guncotton
-first semi sythentic polymer
-accidentally made in a kitchen

Question 8

Bakelite

Answer 8

-first synthetic polymer based on phenol and formaldehyde
-strong and durable
-sub for auto/electric parts

Question 9

Natural polymers

Answer 9

-nucleic acids (DNA, RNA)
-proteins
-polysaccharides

Question 10

Synthetic polymers

Answer 10

-polyethylene, poly-n
-nylon, silicon rubber, rayon, teflon, kevlar

Question 11

Polymer name

Answer 11

-poly + (repeating unit)

Question 12

Polymer structure

Answer 12

-homo
-random co
-alternate co
-block co
-graft co (extends as branch off other polymer)

Question 13

Linear polymers

Question 14

Cross-linked polymers

Question 15

Polymer unit expression

Answer 15

-building block is 2 Carbons not one

Question 16

Polyacrylamide

Answer 16

-run large polymer across network
-surfactant
-run SCC
-electrophoresis? idk
-polymers movement on gel based on density

Question 17

Polymer synthesis methods

Answer 17

-condensation polymerization
-addition polymerization

Question 18

Condensation polymerization

Answer 18

-step polymerization
-2 or mote bifunctional monomers w dif functional groups react

Question 19

Addition polymerization

Answer 19

-free-rad polymerization
-chain polymerization
-initiation by adical
-propogation
-termination by inert molecule
-keep recruiting monomers

-polyacrylate and polysyrene

Question 20

Molecular weight of polymers

Answer 20

-Mn (number average)
-Mw (weight average
-monodispersed or polydispersed

Question 21

monodispersed

Answer 21

-Mn=Mw
-Mw/Mn =1 polydispersity

Question 22

polydispersed

Answer 22

-Mw&raquo_space; Mn
-Mw/Mn&raquo_space;1 polydispersity
-broad distribution in weight

Question 23

Crystalline

Answer 23

-linear
-can pack tightly
-T<Tm
-sharp Tm
-food barrier to diffusion
-durable

Question 24

Amorphous

Answer 24

-more common
-irreg structure
-forms glas at T<Tg
-softens over wide temp range

Question 25

Glass transition temperature (Tg)

Answer 25

-temp range where a polymer changes from a hard/rigid/glassy state to more compliant/rubbery state

Question 26

Polymers at T <

Answer 26

-hard, stiff, glassy

Question 27

polymers at T >> Tg

Answer 27

-rubbery and may flow

Question 28

Chewable dosage forms

Answer 28

-polymer with Tg close to 37 -gum is softened at mouth temp -chewing release nicotine release -parking slows release

Question 29

Factors inc Tg

Answer 29

-polymer long length -bulky side chains -crosslinking -plasticizers

Question 30

Plasticizers

Answer 30

-molecules that inc entropy and mobility of polymer chains -lower Tg when in polymer products -water example

Question 31

Mechanical properties of polymers

Answer 31

-stress vs strain (slope) (stiffness) -AUC = touughness

Question 32

elastic polymers

Answer 32

-linear stress vs stain curve up to a breaking point

Question 33

Rubbers or elastomers

Answer 33

-may deform 10-15 times original lengths

Question 34

Hydrogels

Answer 34

-crosslinked network of hydrophillic polymers -swell rapidly in water -retain large volume of water in structure

Question 35

Hydrogel types

Answer 35

-chemical gels (covalent) -physical gels (H bonds, interactions)

Question 36

Hydrogel swelling

Answer 36

-chain-water interaction -electostatic repulsion -osmotic forces

Question 37

Polymers in dosage forms

Answer 37

-cellulose-based -hydrocolloids -water-soluble -water-insolube

Question 38

Cellulose based polymers

Answer 38

-ethylcellulose -carboxymthyl cellulose -hydroxypropyl methy cellulose

Question 39

Hydrocolloids

Answer 39

-alginic acid (thickening agent) -chitosan (mucoadhesive)

Question 40

water-soluble polymers

Answer 40

-poly(ethylene glycol) -poly(vinyl alcohol)

Question 41

water-insoluble polymers

Answer 41

-poly(lactic-co-gycolic acid) -polylactic acid -controlled drug release