Materials Revolution (Exam 1)

Question 1

What are amines?

Answer 1

Amines are organic derivatives of ammonia.

Question 2

How can ammonia acts as a nucleophile?

Answer 2

Ammonia has a lone pair of electrons which it can attack electrophiles with, for instance the polarised carbon in halogenoalkanes or in acyl chlorides. This produces a primary amine.

Question 3

How can an amine act as a nucelophile?

Answer 3

An amine has a lone pair of electrons so can undergo substitution reactions with halogenoalkanes or acyl chlorides to produce secondary and tertiary amines.

Question 4

Which two ways can amides be produced?

Answer 4

1. Nucleophilic substitution of an amine and an acyl chloride (acylation). This reaction is very vigorous as acyl chlorides are very reactive, even at room temperature.
2. A condensation reaction between a carboxylic acid and an amine.

Question 5

What is a monomer?

Answer 5

A monomer is a small molecule which can be combined with other small molecules to form a long chain.

Question 6

What is addition polymerisation?

Answer 6

A reaction involving unsaturated monomers adding together by breaking the C=C double bond and joining.

Question 7

What is polyester?

Answer 7

Polyester is a condensation polymer of diols and diamines.

Question 8

How are nylons named?

Answer 8

Nylon-A,B. A is the number of carbons in the diamine and B is the number of carbons in the carboxylic acid.

Question 9

What is recrystallisation used for?

Answer 9

This is used to purify solid crude organic products. They should contain mainly one type of product with a small amount of impurities.

Question 10

What is the last step of recrystallisation?

Answer 10

The pure crystals can be collected by vacuum filtration, washed with a cold solvent and then dried either in the open, or in an oven.

Question 11

What 4 reasons in recycling done for?

Answer 11

1. To conserve fossil fuel feedstock.
2. To reduce the consumption of energy.
3. To reduce the amount of solid hazardous waste going to landfill.
4. To reduce CO2, SO2 and NO emissions.

Question 12

What three methods are there of recycling polymers?

Answer 12

1. Plastic process scrap recycling
2. Post-use plastic recycling
3. Chemical/feedstock recycling

Question 13

How can metals be recycled?

Answer 13

Aluminium and steel can be easily recycled as they are magnetic so can be easily sorted with magnets. Metal catalysts can also be recycled.

Question 14

Which two types of plastics can be made which are more environmentally friendly?

Answer 14

1. Bioplastics: Polymers from plant sugars and plastics grown in GM plants/microorganisms.
2. Degradable plastics: Biopolymers, synthetic biodegradable plastics and photodegradable plastics.

Question 15

What is the Tm?

Answer 15

The temperature at which a solid melts.

Question 16

What is the Tg?

Answer 16

The temperature below which it becomes glasslike.

Question 17

What four factors affect strength and flexibility?

Answer 17

1. Packing
2. Type of IMB
3. Number of IMBs
4. Cross links

Question 18

What four factors affect packing?

Answer 18

1. Regularity of chain
2. Branches
3. Bulky side groups
4. Plasticisers

Question 19

What four factors affect the type of IMB?

Answer 19

1. Types of atoms
2. Polar groups
3. Atoms which can H bond
4. Atoms of different chains lining up to H bonds

Question 20

What two factors affect the number of IMB?

Answer 20

1. Length of chains

2. Lining up of chains

Question 21

What 3 ways can polymers be modified in?

Answer 21

1. Plasticisers
2. Copolymerisation
3. Cold-drawing