Composition of alginate and reversible hydrocolloid

Question 1

What does Na alginate do?

Answer 1

dissolves in H2O, react with Ca+

Question 2

CaSO4*2H2O does what in alginate?

Answer 2

react with NaAlg, form CaAlg gel

Question 3

What does Na3PO do in alginate?

Answer 3

counteract hydrocolloid, die surface

Question 4

what does diatomaceous earth (silicate powder) do in alginate?

Answer 4

controls consistency of mix, stiffness of impression, adds strength

Question 5

what do glycols do inalginate?

Answer 5

make powder dustless

Question 6

what does wintergreen do in alginate?

Answer 6

taste

Question 7

what does pigments do in alginate?

Answer 7

color

Question 8

what does agar do in reversible hydrocolloid materials?

Answer 8

provide dispersed phase of sol, fibril structure of gel

Question 9

what does K2SO4 do in reversible hydrocolloid materials?

Answer 9

Acts as hardener for gypsum, counteract borax, agar

Question 10

what does borax do in reversible hydrocolloid materials?

Answer 10

improve gel strength, retarder

Question 11

what does alkyl benzoate do in reversible hydrocolloid materials?

Answer 11

inhibit mold growth

Question 12

what does water do in reversible hydrocolloid materials?

Answer 12

provides continuous phases

Question 13

what does color and flavor do in reversible hydrocolloid materials?

Answer 13

appearance and taste

Question 14

What is polysulfides catalyst?

Answer 14

Lead dioxide, PbO2

Question 15

What is condensation silicones catalyst?

Answer 15

Alkyl silicate plus stannous octave

Question 16

What is addition silicone’s catalyst?

Answer 16

Platinum salt

Question 17

What is polyether’s catalysts?

Answer 17

Aromatic sulfonate