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Flashcards in Polymers Deck (27)
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1

denture base

acrylic resin

2

impression

elastomer

3

direct filling

complete resin

4

dental polymer

polyethylene

5

bonding in polymers

covalent and secondary bonding

6

control of polymer properties

Molecular weight, chemical composition, thermal properties, molecule structure

7

average molecular weight

number (n) of repeating unit (mer) x molecular weight of (mer)

8

number of repeating unit (mer)

degree of polymerization

9

degree of polymerization =

average Me/mer molecule weight

10

high degree of polymerization

longer polymer chains, more rigid, less soluble

11

low degree of polymerization

shorter polymer chains, less stiff, more soluble

12

covalent bonding as -- electric conductivity

low

13

linear polymer has weak --

secondary bonding

14

-- polymers have reversible transformation

thermoplastic

15

-- polymers are irreversible

thermoset

16

heat thermoplastic polymer -->

softens it

17

cool thermoplastic polymer -->

cools it

18

heat thermoset polymer -->

hardens it

19

thermoplastic polymers are --

linear with some branches

20

thermoset polymers are -- or --

crosslinked or networked

21

thermoset are -- than thermoplastics

harder, stronger and more brittle

22

resin 1 phenol rings -->

shift central backbone

23

resin 2 linear backbone -->

lower viscosity than resin 1

24

resin 3 low Me and linear backbone -->

diluent

25

the presence of -- used to increase the strength and abscission resistance

fillers

26

dental composite: polymer resin =

continuous phase

27

dental composite: ceramic filler =

dispersed phase