Lecture 5

Question 1

Functions of Thickeners

Answer 1

Control phase separation, prevent syneresis, suspend particulate materials, form gels, retard or eliminate crystal growth, extend shelf life, and have a positive effect on product application

Question 2

Shear Stress

Answer 2

external force applied over an area

Question 3

Shear Rate

Answer 3

ratio of velocity of material to its distance from a stationary object

Question 4

Shear Strain

Answer 4

Relative displacement of the faces of a sheared body divided by the distance between them (measure of deformation)

Question 5

Viscosity

Answer 5

Measure of material’s resistance to flow.

Question 6

Concentration-Response Function

Answer 6

The viscosity/thickness response of the solvent media versus concentration is dependent on interaction of particles with each other, the solvent, and other ingredients

Question 7

Critical Overlap Concentration

Answer 7

Concentration above which dramatic viscosity increase occurs due to interaction of polymer molecules to form interpenetrating networks in the solvent

Question 8

Carbomers

Answer 8

most popular aqueous phase thickener used in personal care emulsions, MUST BE NEUTRALIZED

Question 9

Liquid Dispersion Polymers

Answer 9

Polymer thickener dispersed in emollient solvent with nonionic dispersant/emulsifier. Used as self-emulsifying systems

Question 10

Carrageenan

Answer 10

Helps stabilize freeze-thaw

Question 11

Why is chitosan used?

Answer 11

It is anionic, used most frequently in conditioners

Question 12

Xanthan Gum

Answer 12

food-grade thickener

Question 13

What is polyquaternium-10?

Answer 13

A cationic group attached to hydroxyethyl cellulose