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Flashcards in polymers Deck (43)
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1

the extent to which all (entire) monomer is polymerized

degree of conversion

2

Two molecules react to form a larger molecules with
elimination of a small molecule

condensation polymerization

3

free radicals react with double bond of a monomer for

crosslinking

4

-- is activated with light

camphoroquinone (CQ)

5

added to polymer to modify the physical properties

plasticizer

6

Minimize or prevent spontaneous or accidental
polymerization of monomers

inhibitors

7

Polymers containing two or more chemically different
types of monomer units to create different polymer
properties

copolymer

8

low MW monomer =

diluent

9

condensation polymerization --> like water and alcohols

byproducts

10

condensation polymerization --> -- dimensional stability

low (shrinkage)

11

Two molecules react to form a larger molecule without
the elimination of a small molecule

additional polymerization (no byproduct)

12

additional polymerization --> -- in composition

no change

13

additional polymerization --> -- dimensional stability

better

14

examples of additional polymerization

free-radical and ring opening

15

most dental resins are formed from --

additional polymerization

16

silicone impression material

condensation polymerization

17

most common type of additional polymerization

free radical

18

CQ absorbs light and --

releases free radicals

19

activator of CQ

blue light

20

accelerator of CQ

DMAM

21

Do plasticizers participate in the polymerization rxn?

no

22

do plasticizers become part of polymer chain?

no

23

plasticizers -- attraction between polymer chains

reduce

24

plasticizers -- the polymer

softens (more flexible)

25

dibutyl phthalate makes denture polymer rubbery

plasticizer

26

free radical scavengers

oxygen, HQ, MEHQ, BHT

27

main inhibitor for most systems

oxygen

28

very efficient inhibitor but causes discoloration

HQ

29

MEHQ is an --

excellent inhibitor

30

BHT produces -- discoloration

less