Mechanical Terms

Question 1

Loss modulus

Answer 1

The measure of energy converted to heat – tells us about the liquid portion of a polymer

Question 2

Storage modulus

Answer 2

Tells us about the elastic or solid response of a material

Question 3

Resiliency

Answer 3

The capacity of a material to absorb energy when it is elastically deformed

Question 4

Ductility

Answer 4

A measure of a material’s ability to undergo appreciable plastic deformation before fracture

Question 5

Toughness

Answer 5

Can be expressed as:
- Materials resistance to fracture when a crack is present
- Ability of a material to absorb energy and plastically deform before fracturing
- Total area under the stress-strain curve taken to fracture

Question 6

Young’s modulus

Answer 6

The ratio of stress to strain when deformation is totally elastic — measure of stiffness

Question 7

Shear modulus

Answer 7

The ratio of shear stress to shear strain when deformation is totally elastic

Question 8

Yield strain

Answer 8

The strain at which the material plastically deforms

Question 9

Yield stress

Answer 9

The stress required to product a very slight yet specified amount of plastic strain – strain offset of 0.002

Question 10

Plasticizer

Answer 10

A low molecular weight polymer additive that enhances flexibility and workability and reduces stiffness and brittleness — results in the reduction of Tg

Question 11

Compressibility

Answer 11

The response to externally applied pressures