Polymer Chemistry - Lesson 10

Flashcards reviewing copolymerization concepts, including types, mechanisms, and applications.

What is a Ziegler-Natta catalyst?

A coordination catalyst used to polymerize olefins, consisting of a metal compound (e.g., titanium trichloride) and an organometallic compound (e.g., triethylaluminum).

What kind of polymers does Ziegler-Natta catalyst produce, unlike free radical initiators?

Polymers with higher linearity and narrower molecular weight distribution.

What can the composition of a Ziegler-Natta catalyst influence?

Influence the properties of the resultant polymer.

What process requires two different catalysts A and B?

The oligomerization of ethylene via ZN catalyst A, and the copolymerization of α-olefin with ethylene via ZN catalyst B to form LLDPE.

What is block copolymerization?

A polymer composed of blocks of different polymerized monomer subunits.

What can also produce block copolymers?

Step growth polymerization .

What is a di-telechelic polymer?

A linear polymer with reactive groups at both chain ends.

Give an example of a two-prepolymer method.

Hydroxyl-terminated polyether reacted with isocyanate-terminated polyurethane.

What does 'grafting from' technique mean?

Polymerise monomers in the presence of a previously formed polymer by the initiation of growth through chain transfer.

What factor will decide the length of the chain?

The frequency of the transfer.

What 3 monomers is ABS comprised of?

Acrylonitrile, 1,3-butadiene, and styrene.

How can the properties of ABS be controlled?

Varying the ratio of the three components.

How are butadiene monomers polymerized?

First polymerized via free radical polymerization.

What occurs while grafted onto the polybutadiene backbone as branches?

Copolymerization of acrylonitrile and styrene monomers

What process is used to form ABS polymer?

A two-time emulsion process.