Podcast
Questions and Answers
Molecular weight of polymer may be controlled by adding catalyst.
Molecular weight of polymer may be controlled by adding catalyst.
True
Rate of Propagation is not the same as the rate of disappearance of monomer.
Rate of Propagation is not the same as the rate of disappearance of monomer.
False
Free radical polymerization is an endothermic reaction.
Free radical polymerization is an endothermic reaction.
False
Cationic polymerization is an endothermic reaction.
Cationic polymerization is an endothermic reaction.
Signup and view all the answers
Activation energy in cationic polymerization is about 20 K cal/mole.
Activation energy in cationic polymerization is about 20 K cal/mole.
Signup and view all the answers
High molecular weight polymers are obtained at high temperature.
High molecular weight polymers are obtained at high temperature.
Signup and view all the answers
Refractive index does not depend on the temperature.
Refractive index does not depend on the temperature.
Signup and view all the answers
Viscosity depends only on the polymerization concentration.
Viscosity depends only on the polymerization concentration.
Signup and view all the answers
Molecular weight of polymer may be controlled by removing small molecules.
Molecular weight of polymer may be controlled by removing small molecules.
Signup and view all the answers
Depolymerization is the same as propagation.
Depolymerization is the same as propagation.
Signup and view all the answers
Free radical polymerization is an exothermic reaction.
Free radical polymerization is an exothermic reaction.
Signup and view all the answers
Activation energy in free radical polymerization is less than 20 K cal/mole.
Activation energy in free radical polymerization is less than 20 K cal/mole.
Signup and view all the answers
Cationic polymerization is an endothermic reaction.
Cationic polymerization is an endothermic reaction.
Signup and view all the answers
High molecular weight polymers are obtained at low temperature.
High molecular weight polymers are obtained at low temperature.
Signup and view all the answers
Viscosity depends only on the molecular weight.
Viscosity depends only on the molecular weight.
Signup and view all the answers
Block copolymers have similar properties.
Block copolymers have similar properties.
Signup and view all the answers
Study Notes
Controlling Molecular Weight
- Molecular weight of polymer can be controlled by removing small molecules.
- Molecular weight of polymer can be controlled by raising the temperature.
- Molecular weight of polymer can be controlled by adding catalyst.
Rate of Propagation
- Rate of Propagation is the same as the rate of disappearance of monomer.
Depolymerization
- Depolymerization is the reverse of propagation.
Free Radical Polymerization
- Free radical polymerization is exothermic.
- Free radical polymerization increases more rapidly with increasing temperature.
- Activation energy in free radical polymerization is greater than 20 K cal/mole.
Cationic Polymerization
- Cationic polymerization is exothermic.
- Activation energy in cationic polymerization is about 5-7 k cal/mole.
- Cationic polymerization is very rapid.
- High molecular weight polymers are obtained at low temperature.
Factors Affecting Cationic Polymerization
- Dielectric constant and solvating tendency of the medium may have an effect on ionic polymerization.
- Strong Lewis acids are able to initiate cationic polymerization.
Polymerization System
- There is a linear relationship between the degree of conversion in the polymerization system and its volume.
Properties of Polymers
- Refractive index depends significantly on the temperature.
- Viscosity depends on both polymerization concentration and molecular weight.
- Conductance of polymer decreases as polymerization proceeds.
Copolymers
- Block copolymers have different properties.
- Random copolymers usually form a homogeneous phase.
- Amorphous homopolymers consist of a single phase.
- Phase formation in copolymerization depends on the values of r1 and r2.
- When r1 > 1, r2 > 1, it forms a mixture of two homogeneous phases.
- When r1 or r2 = 0, it forms a zeotropic composition.
- When r1 = r2 = 0, it forms not homopolymers but alternating copolymers.
- When r1 = r2 = 1, it forms an ideal copolymerization.
- When r1 = r2 = 0, type 11 and 22 are not possible.
- When r1 = r2 = 1, type 11, 22, 12, and 21 are possible.
Controlling Molecular Weight
- Molecular weight of polymer can be controlled by removing small molecules.
- Molecular weight of polymer can be controlled by raising the temperature.
- Molecular weight of polymer can be controlled by adding catalyst.
Rate of Propagation
- Rate of Propagation is the same as the rate of disappearance of monomer.
Depolymerization
- Depolymerization is the reverse of propagation.
Free Radical Polymerization
- Free radical polymerization is exothermic.
- Free radical polymerization increases more rapidly with increasing temperature.
- Activation energy in free radical polymerization is greater than 20 K cal/mole.
Cationic Polymerization
- Cationic polymerization is exothermic.
- Activation energy in cationic polymerization is about 5-7 k cal/mole.
- Cationic polymerization is very rapid.
- High molecular weight polymers are obtained at low temperature.
Factors Affecting Cationic Polymerization
- Dielectric constant and solvating tendency of the medium may have an effect on ionic polymerization.
- Strong Lewis acids are able to initiate cationic polymerization.
Polymerization System
- There is a linear relationship between the degree of conversion in the polymerization system and its volume.
Properties of Polymers
- Refractive index depends significantly on the temperature.
- Viscosity depends on both polymerization concentration and molecular weight.
- Conductance of polymer decreases as polymerization proceeds.
Copolymers
- Block copolymers have different properties.
- Random copolymers usually form a homogeneous phase.
- Amorphous homopolymers consist of a single phase.
- Phase formation in copolymerization depends on the values of r1 and r2.
- When r1 > 1, r2 > 1, it forms a mixture of two homogeneous phases.
- When r1 or r2 = 0, it forms a zeotropic composition.
- When r1 = r2 = 0, it forms not homopolymers but alternating copolymers.
- When r1 = r2 = 1, it forms an ideal copolymerization.
- When r1 = r2 = 0, type 11 and 22 are not possible.
- When r1 = r2 = 1, type 11, 22, 12, and 21 are possible.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers various aspects of polymerization, including controlling molecular weight, propagation, and depolymerization. It also touches on free radical polymerization and its relationship with temperature.
