3- Structure Of Matter + Polymer Chemistry

Question 1

Adhesion

Answer 1

Unlike molecules attracted

Question 2

Cohesion

Answer 2

Like molecules attracted

Question 3

Adhesive

Answer 3

Material used to cause adhesion

Question 4

Adherend

Answer 4

Material that adhesive is applied to

Question 5

Tarnish

Answer 5

Metal surface loses its lustre when a chemical reaction causes a thin film to form

Occurs following formation of deposits on a surface (Ex. Micro-organism film)

Question 6

Corrosion

Answer 6

Metal attacked by environmental agent and begins to dissolve

Question 7

Dry/Chemical Corrosion

Answer 7

Direct combination of metallic/non-metallic elements to yield a chemical compound

No water

Ex. Oxidation

Question 8

Wet/Electrochemical Corrosion

Answer 8

Requires water or electrolytes

Involves transfer of electrons from one material to another

Question 9

Fillers

Answer 9

Increases Young’s modulus/rigidity- will not deform under stress

Question 10

Plasticizers

Answer 10

Small molecules added to soften a polymer

Question 11

Factors Affecting Crystallinity

Answer 11

Chain length and flexibility (double bonds can’t rearrange- prevents close packing)

Side chains
Intermolecular forces- self assembly of polymers

Question 12

Properties of Dental Resins

Answer 12

Mechanical
Rheometric
Salvation
Thermal

Question 13

Factors Affecting Tm and Tg

Answer 13

Crystallinity (harder to break bonds= higher Tg) 
Chain stiffness (increases Tm and Tg)
Side groups, polar groups, double bonds, aromatics- increase Tg (more amorphous= higher Tg)