Ch. 2 - Biomass Research

Question 1

Explain what is meant by a condensation polymer

Answer 1

Condensation polymers are polymers that form by the elimination of a small molecule (e.g. H2O) when pairs of monomer molecules join together. Unlike addition polymerisation, not all the atoms of the monomers are found in the final polymer.

Question 2

Describe the reaction involved when a condensation polymer is formed.

Answer 2

• Involves reaction between two different functional groups, each belonging to a monomer, in which a molecule of water (or another small molecule) is eliminated as each monomer releases one or more atoms
  
  • thus allowing the two functional groups become linked together at where the functional group once was

Question 3

Structure of glucose monomer

Answer 3

Question 4

Structure of cellulose

Answer 4

Question 5

identify cellulose as an example of a condensation polymer found as a major component of biomass

Answer 5

• An example of a condensation polymer found as a major component of the biomass in plants giving them their strength and shape
• A naturally occurring biopolymer formed by the condensation polymerisation of monomer, beta glucose

Question 6

Identify that cellulose contains the basic carbon-chain structures needed to build petrochemicals

Answer 6

• Cellulose contains the basic carbon-chain structures needed to build compounds presently obtained from petrochemicals
  
  • C-H, C-C bonds; but also contains C-O-H and C-O-C not found in hydrocarbons; OH groups cause greater dispersion forces

Question 7

How can cellulose be used as a raw material?

Answer 7

• Cellulose could be used as a source of ethylene, and thereby, a raw material
• In both treatment processes, the solution of glucose can be treated with yeast to form ethanol, and if required this can be dehydrated to ethane

Question 8

Advantages of using cellulose as a raw material for the polymer industry?

Answer 8

• There is an abundance of cellulose on earth; major component of biomass (plant matter)
• Cellulose is biodegradable, which is major issue for current raw materials
• Cellulose sources can be quickly replenished as plants contain them, hence renewable resource that will not run out like current petroleum-based materials

Question 9

Disadvantages of using cellulose as a raw material for the polymer industry?

Answer 9

• Cellulose is difficult to break down into glucose
  
  • Long near-linear chains of cellulose hydrogen bond to one another form very compact fibres
  • Therefore hard for chemicals to come into contact with the glucose-glucose links to break them
• High cost despite the lower starting cost of the starting material
• Much of the energy required for this process (keeping temperatures high and driving the process machinery) may come from oil
  
  • Hence more oil would be used than cracking the oil directly to ethylene.