Question 1

Describe what plasticizers are and give an example.

Accepted Answer

An organic compound that disso

Question 2

Propose a mechanism for the following polymerization reaction:

Accepted Answer

The answer of Propose a mechanism for the following polymerization...

Question 3

Which of the following is a possible step to terminate a chain in the radical polymerization of ethylene?

Accepted Answer

A) ROOR + CH2     CH2 → ROCH2CH2OR 
B) CH2     CH2 + CH2
    CH2 → CH3CH   CHCH3 
C) ∙ RO∙ + CH2
    CH2 → ROCH2
    CH2 
D) ∙ ∙ ROCH2CH2 + CH2
    CH2 → ROCH2CH2CH2CH2 
E) ∙ 2 RO-[CH2CH2]n-CH2CH2 →
RO-[CH2CH2]n-CH2CH2CH2CH2-[CH2CH2]n-OR 
A) ROOR + CH2     CH2 → ROCH2CH2OR 
B) CH2     CH2 + CH2
    CH2 → CH3CH   CHCH3 
C) ∙ RO∙ + CH2
    CH2 → ROCH2
    CH2 
D) ∙ ∙ ROCH2CH2 + CH2
    CH2 → ROCH2CH2CH2CH2 
E) ∙ 2 RO-[CH2CH2]n-CH2CH2 →
RO-[CH2CH2]n-CH2CH2CH2CH2-[CH2CH2]n-OR

Question 4

Epoxy resin is a copolymer of

Accepted Answer

A) bisphenol A and epichlorohydrin. 
B) bisphenol A and diphenyl carbonate. 
C) bisphenol A and dimethylterephthalate. 
D) bisphenol A and ethylene glycol. 
E) bisphenol A and 1,4-diaminobenzene. 
A) bisphenol A and epichlorohydrin. 
B) bisphenol A and diphenyl carbonate. 
C) bisphenol A and dimethylterephthalate. 
D) bisphenol A and ethylene glycol. 
E) bisphenol A and 1,4-diaminobenzene.

Question 5

When 3-methyl-1-butene
CH2
    CHCH(CH3)2
undergoes cationic polymerization,the following expected carbocation is formed.
⊕
X-CH2-CH-CH(CH3)2
However,the following carbocation is also found in the reaction.
⊕
X-CH2-CH2-C(CH3)2
Explain.

Accepted Answer

The expected carbocation is a

Question 6

Why is chain branching less common in anionic polymerization than in cationic polymerization?

Accepted Answer

The intermediate which leads t

Question 7

List the three phases in the mechanism of chain-growth polymerization.

Accepted Answer

1.Initiati

Question 8

Isoprene is the monomer present in

Accepted Answer

A) natural rubber. 
B) synthetic rubber. 
C) gutta percha. 
D) A and B. 
E) A and C. 
A) natural rubber. 
B) synthetic rubber. 
C) gutta percha. 
D) A and B. 
E) A and C.

Question 9

Which of the following statements concerning the stereochemistry of polymerization is correct?

Accepted Answer

A) Polymers in the atactic configuration are more likely to be crystalline solids because regular packing of the polymer chains is easier. 
B) Polymers in the isotactic configuration tend to be softer and more flexible than atactic polymers. 
C) In general,radical polymerization leads primarily to branched polymers in the syndiotactic configuration. 
D) The percentage of chains in the isotactic or syndiotactic configuration decreases as the polymerization temperature decreases. 
E) none of the above 
A) Polymers in the atactic configuration are more likely to be crystalline solids because regular packing of the polymer chains is easier. 
B) Polymers in the isotactic configuration tend to be softer and more flexible than atactic polymers. 
C) In general,radical polymerization leads primarily to branched polymers in the syndiotactic configuration. 
D) The percentage of chains in the isotactic or syndiotactic configuration decreases as the polymerization temperature decreases. 
E) none of the above

Question 10

What are aramides?

Accepted Answer

A) aromatic polyester polymers 
B) aromatic amine polymers 
C) alkyl halide polymers 
D) aromatic polyamide polymers 
E) aliphatic polyamide polymers 
A) aromatic polyester polymers 
B) aromatic amine polymers 
C) alkyl halide polymers 
D) aromatic polyamide polymers 
E) aliphatic polyamide polymers

Question 11

What are crystallites?

Accepted Answer

The regions of polym

Question 12

Which of the following initiators are known as Ziegler-Natta catalysts,which were discovered in 1953 in order to control the stereochemistry of polymers?

Accepted Answer

A) Al/Ti initiators 
B) Ni/Cd initiators 
C) Zn/Hg initiators 
D) Pb/C initiators 
E) Pb/PbO2 initiators 
A) Al/Ti initiators 
B) Ni/Cd initiators 
C) Zn/Hg initiators 
D) Pb/C initiators 
E) Pb/PbO2 initiators

Question 13

Which of the following are characteristic of linear polyethylene?

Accepted Answer

A) They are branched polymers. 
B) They are known as high-density polyethylene. 
C) They are soft and flexible polymers. 
D) A and B 
E) A and C 
A) They are branched polymers. 
B) They are known as high-density polyethylene. 
C) They are soft and flexible polymers. 
D) A and B 
E) A and C

Question 14

From which of the following compounds is Lucite or poly(methyl methacrylate)prepared?

Accepted Answer

A) CH2     CHCH3 
B) CH2     C(CH3)O2CCH3 
C) CH2     CHO2CCH3 
D) CH2     C(CH3)CO2CH3 
E) CH2     CHCO2CH3 
A) CH2     CHCH3 
B) CH2     C(CH3)O2CCH3 
C) CH2     CHO2CCH3 
D) CH2     C(CH3)CO2CH3 
E) CH2     CHCO2CH3

Question 15

What advantage does a Lewis acid like BF3 have over a proton-donating acid like HCl as a initiator in cationic polymerization?

Accepted Answer

The advantage of a Lewis acid

Question 16

Show how branching could occur during the free-radical polymerization of styrene.

Accepted Answer

The answer of Show how branching could occur during the...

Question 17

ABS is a copolymer of what three monomers?

Accepted Answer

acrylonitr

Question 18

Draw a short segment of neoprene,using four monomers.

Accepted Answer

The answer of Draw a short segment of neoprene,using four...

Question 19

Which is not typically made through radical polymerization?

Accepted Answer

A) poly(styrene) 
B) PVC 
C) Dacron 
D) poly(vinyl acetate) 
E) Lucite 
A) poly(styrene) 
B) PVC 
C) Dacron 
D) poly(vinyl acetate) 
E) Lucite

Question 20

Give the product of the following polymerization.

Accepted Answer

The answer of Give the product of the following polymerization....

Exam 27: Synthetic Polymers

Describe what plasticizers are and give an example.

Propose a mechanism for the following polymerization reaction:

Which of the following is a possible step to terminate a chain in the radical polymerization of ethylene?

Epoxy resin is a copolymer of

When 3-methyl-1-butene CH2 CHCH(CH3)2 undergoes cationic polymerization,the following expected carbocation is formed. ⊕ X-CH2-CH-CH(CH3)2 However,the following carbocation is also found in the reaction. ⊕ X-CH2-CH2-C(CH3)2 Explain.

Why is chain branching less common in anionic polymerization than in cationic polymerization?

List the three phases in the mechanism of chain-growth polymerization.

Isoprene is the monomer present in

Which of the following statements concerning the stereochemistry of polymerization is correct?

What are aramides?

What are crystallites?

Which of the following initiators are known as Ziegler-Natta catalysts,which were discovered in 1953 in order to control the stereochemistry of polymers?

Which of the following are characteristic of linear polyethylene?

From which of the following compounds is Lucite or poly(methyl methacrylate)prepared?

What advantage does a Lewis acid like BF3 have over a proton-donating acid like HCl as a initiator in cationic polymerization?

Show how branching could occur during the free-radical polymerization of styrene.

ABS is a copolymer of what three monomers?

Draw a short segment of neoprene,using four monomers.

Which is not typically made through radical polymerization?

Give the product of the following polymerization.

Remembering General Chemistry: Electronic Structure and Bonding

Acids and Bases: Central to Understanding Organic Chemistry

An Introduction to Organic Compounds: Nomenclature, physical Properties, and Structure

Isomers: the Arrangement of Atoms in Space

Alkenes: Structure,nomenclature,and an Introduction to Reactivity - Thermodynamics and Kinetics

The Reactions of Alkenes - the Stereochemistry of Addition Reactions

The Reactions of Alkynes - Introduction to Multistep Synthesis

Delocalized Electrons: Their Effect on Stability, pka, and the Products of a Reaction - Aromaticity and Electronic Effects: an Introduction to the Reactions of Benzene

Substitution and Elimination Reactions of Alkyl Halides

Reactions of Alcohols, ethers, epoxides, amines and Sulfur-Containing Compounds

Organometallic Compounds

Radicals

Mass Spectrometry,infrared Spectroscopy,and Uvvis Spectroscopy

Nmr Spectroscopy

Reactions of Carboxylic Acids and Carboxylic Acid Derivatives

Reactions of Aldehydes and Ketones

Reactions at the Α-Carbon

Reactions of Benzene and Substituted Benzenes

More About Amines - Reactions of Heterocylic Compounds

The Organic Chemistry of Carbohydrates

Amino Acids,peptides,and Proteins

Catalysis in Organic Reactions and in Enzymatic Reactions

The Organic Chemistry of the Coenzymes, compounds Derived From Vitamins

The Organic Chemistry of the Metabolic Pathways

The Organic Chemistry of Lipids

The Chemistry of the Nucleic Acids

Pericyclic Reactions

Filters

When 3-methyl-1-butene CH₂ CHCH(CH₃)₂ undergoes cationic polymerization,the following expected carbocation is formed. ⊕ X-CH₂-CH-CH(CH₃)₂ However,the following carbocation is also found in the reaction. ⊕ X-CH₂-CH₂-C(CH₃)₂ Explain.

What advantage does a Lewis acid like BF₃ have over a proton-donating acid like HCl as a initiator in cationic polymerization?