Polymer

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What is polyethylene derived from?

Ethylene (correct)

Polymethylmethacrylate

Propylene

Polyacrylic acid

Which polymer is produced through the polymerization of propylene?

Polyvinyl chloride

Polytetrafluoroethylene

Polypropylene (correct)

Polymethylmethacrylate

What is the role of free radicals in the polymerization of vinyl compounds?

They inhibit the process

They are catalysts

They terminate polymer chains

They initiate the polymerization process (correct)

During which step of the polymerization process are free radicals produced?

Activation Signup and view all the answers

What is the consequence of the decomposition of benzoyl peroxide in polymerization?

It yields two free radicals Signup and view all the answers

Which of the following is NOT a polymer listed in the provided information?

Polystyrene Signup and view all the answers

What type of reaction leads to the creation of polymers like PVC and PTFE from their respective monomers?

Addition reaction Signup and view all the answers

What is a significant characteristic of polyblend compared to its constituent polymers?

The properties often lie between those of its constituent polymers. Signup and view all the answers

Which statement accurately describes copolymerization?

Monomers A and B are mixed during the polymerization process. Signup and view all the answers

What is the role of plasticizers in polymer processing?

To reduce the attractive forces between polymer chains. Signup and view all the answers

Which of the following statements is true regarding ABS copolymer?

It consists of a mixture of acrylonitrile, butadiene, and styrene. Signup and view all the answers

What is required for a plasticizer to be effectively used in a polymer?

It must be low molecular weight and cause permanent changes in properties. Signup and view all the answers

Which type of polymer arrangement does NOT typically include cross-linking?

Thermoplastic Signup and view all the answers

Which method for initiating vinyl polymerization directly involves the generation of free radicals through thermal decomposition?

Heating above 65°C Signup and view all the answers

What role does n,n-dimethyl-p-toluidine play in the polymerization process involving benzoyl peroxide?

It activates benzoyl peroxide to produce free radicals. Signup and view all the answers

In the propagation phase of polymerization, what is the primary action of the free radical formed during initiation?

It transfers itself to a monomer to start a chain reaction. Signup and view all the answers

Which of the following statements about benzoyl peroxide as a polymerization initiator is FALSE?

It does not require any external activators. Signup and view all the answers

What is a common application of polymerization techniques involving benzoyl peroxide?

Making acrylic resin denture bases Signup and view all the answers

Which of the following is an example of a synthetic polymer?

Nylon Signup and view all the answers

What is the monomer from which polyethylene is derived?

Ethylene Signup and view all the answers

Which type of polymer is formed from a single type of monomer?

Homopolymer Signup and view all the answers

In polypropylene, the arrangement of which group can vary?

Methyl groups Signup and view all the answers

What is the fundamental component of living organisms that is also a polymer?

Silk Signup and view all the answers

What characterizes addition polymerization?

Molecules react to form larger molecules without loss of smaller molecules Signup and view all the answers

Which of the following best describes a heteropolymer?

Formed from multiple types of monomers Signup and view all the answers

What distinguishes isotactic polypropylene from atactic polypropylene?

All methyl groups are on one side of the polymer chain Signup and view all the answers

Which example demonstrates an inorganic polymer?

Polydimethylsiloxane Signup and view all the answers

What is the repeating unit in polyethylene?

$CH_2$ Signup and view all the answers

What is a defining characteristic of a composite material?

The individual components retain their physical identity Signup and view all the answers

Which of the following best describes the role of the matrix in a two-component composite?

To connect and bind the filler Signup and view all the answers

Which material type in particulate composites is known to possibly reduce cost?

Filler particles Signup and view all the answers

What is the primary effect of the orientation or distribution of fibers in a composite material?

Influences the material's strength and stiffness Signup and view all the answers

Which of the following statements is true regarding whiskers compared to fibers?

Whiskers provide substantial tensile strength Signup and view all the answers

In a laminate structure, what is the effect of placing layers of fiber-reinforced resin in different directions?

Enhances strength in multiple directions Signup and view all the answers

What is the tensile strength range for Aluminium oxide whiskers?

14000-28000 MPa Signup and view all the answers

Which fiber type has the lowest tensile strength according to the provided data?

Carbon Signup and view all the answers

What characterizes elastomers as a material?

They can stretch multiple times their original length. Signup and view all the answers

What effect does cross-linking have on polymer properties?

It transforms a liquid polymer into a solid material. Signup and view all the answers

Which factor does NOT influence the crystallinity of a polymer?

Time spent in liquid state Signup and view all the answers

What happens to polyethylene when heated above its glass transition temperature?

It softens and can be reshaped before returning to its original form. Signup and view all the answers

What defines a thermosetting polymer?

It degrades on heating without showing a glass transition temperature. Signup and view all the answers

What does the glass transition temperature primarily indicate for a polymer?

The temperature at which the polymer can be reshaped without permanent deformation. Signup and view all the answers

How does branched polyethylene differ from linear polyethylene?

It has a three-dimensional network that restricts movement even when heated. Signup and view all the answers

What transformation occurs in silicone polymers at temperatures below room temperature?

They function as liquids due to their low glass transition temperature. Signup and view all the answers

Which characteristic is NOT associated with elastomers?

High strains that are irreversible. Signup and view all the answers

What role does the bond strength play in determining a polymer's properties?

It governs the elasticity and stretchability of the polymer. Signup and view all the answers