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Flashcards in Materials Revolution Deck (28):
0

what is the structure of ammonia?

3 hydrogen atoms bonded to a central nitrogen atom- lone pair on N

1

What is the structure of amines?

Same as ammonia but one or more of the hydrogens is substituted for an alkyl group.

2

What properties is the lone pair on the nitrogen in amines responsible for?

they can act as bases, nucleophiles, ligands

3

What is a secondary amine?

Where the nitrogen atom is bonded to two alkyl or aryl groups

4

what is an aryl group?

a benzene ring with one hydrogen substituted eg phenyl, C6H5 -

5

Name this amine:
CH3CH(NH2)CH3

2-propylamine

6

Name this amine:
C6H5NH2

phenylamine

7

What happens when amines dissolve in water and why?

they form weakly alkaline solutions as they are bases

8

What can amines accept a hydrogen ion from?

water/ an acid

9

What is formed when a primary amine reacts with a halogenoalkane?
What is the amine acting as?

A secondary amine
A nucleophile

10

when hydrogen atoms on an amine are replaced by alkyl groups what type of reaction is this?

An alkylation reaction

11

What type of reaction do amines undergo with acyl chlorides?
What is the product?

An acylation reaction, forming a secondary amide.

12

what is the general formula of a primary amide?

R group, NH2 group and =O bonded to a carbon

13

What is different about a secondary amide?

One of the H groups on the nitrogen is substituted for an R group

14

what bond is broken when amides are hydrolysed?

The C-N bond

15

what are the products of acid hydrolysis of amides?

a carboxylic acid and an alkyl ammonium ion

16

what are the products of alkaline hydrolysis?

a carboxylate anion and an amine

17

What happens in condensation polymerisation?

Two monomers join together to form a condensation polymer and a small molecule such as water or HCl is eliminated.

18

What must monomers have to form a condensation polymer?

reactive groups at each end

19

what are crystalline regions and when is there a higher percentage of them?

Parallel strands packed close together that make the polymer stiffer
when it is cooled

20

what are amorphous regions?

Randomly arranged chains that make it more flexible

21

What is the glass transition temperature?

when a polymer is cooled this is reached and it becomes brittle and glass like

22

what imf are between polyesters?

pd-pd

23

what imf are between polyamides/nylons?

hydrogen bonds

24

what does copolymerisation do?

adds side groups which pushes chains apart and lowers Tg

25

what do plasticisers do?

allow chains to slide over each other easily lowering Tg

26

how does cold drawing make polymers stronger?

as its stretched a neck forms where chains are aligned so more imf can form

27

what are 3 types of degradable plastics?

biopolymers, synthetic biodegradable plastics, photodegradable plastics