WorksheetsQuiz on Polymer Morphology
Total questions: 17
Worksheet time: 9mins
What are the three states in which small molecules mostly exist?
Solid, Gas, Vapor
Solid, Liquid, Gas
Solid, Liquid, Plasma
Gas, Liquid, Plasma
What characterizes amorphous polymers?
High crystallinity
High melting point
Lack of order among molecules
Regular arrangement of molecules
Which of the following is an example of a crystalline polymer?
Natural rubber
Nylons
PMMA
PS
What is the term for the process of heating and holding a polymer at a temperature below its melting point?
Quenching
Crystallization
Cooling
Annealing
What happens to amorphous polymers as the temperature is raised?
They become more brittle
They change from glassy to rubbery state
They crystallize
They decompose
What is the glass transition temperature (Tg)?
Temperature at which a polymer decomposes
Temperature at which a polymer transitions from rubbery to glassy state
Temperature at which a polymer becomes glassy
Temperature at which a polymer melts
Which factor does NOT influence polymer morphology?
Substituent groups
Color of the polymer
Cooling rate
Size and shape of monomers
What is the effect of rapid quenching on polymers?
Increases crystallinity
Enhances mechanical properties
Yields highly amorphous materials
Forms crystalline structures
What is the characteristic of glassy polymers?
They are elastic
They are dimensionally stable
They are flexible
They have high impact strength
Which of the following is an example of an elastomer?
Polystyrene
Polycarbonate
Polyethylene
Natural rubber
What effect does cross-linking have on Tg?
Decreases Tg
No effect on Tg
Makes Tg variable
Increases Tg
What happens to Tg with increasing chain length?
Decreases
Increases until a limiting value is reached
Fluctuates randomly
Remains constant
Which of the following groups leads to a higher Tg due to increased dipole-dipole interaction?
Ethyl
Hydroxy
Methyl
Butyl
What is the effect of plasticizers on Tg?
Make Tg unpredictable
Increase Tg
Decrease Tg
No effect on Tg
What is a characteristic of crystalline polymers at temperatures above Tg?
They remain glassy
They melt to a viscous liquid
They lose all structure
They become brittle
Which of the following polymers is known to be glassy at room temperature?
Natural rubber
Polystyrene
Polyethylene
Polyurethane
What is the relationship between flexibility and Tg?
Higher flexibility leads to higher Tg
Lower flexibility leads to higher Tg
Flexibility has no effect on Tg
Flexibility and Tg are inversely related
