Unit 1 - Lecture 3 Topic 2

Question 1

Textile fibres are composed of small units called ________ linked to form long chains called ________.

Answer 1

Monomers, polymers

Question 2

What are fibre properties influenced by?

Answer 2

The nature of the monomers, length of chain (known as the degree of polymerization), and arrangement of chains in the fibre.

Question 3

Degree of Polymerization:

Answer 3

The length of a polymer, or how many times the monomer repeats along a chain. It can range from 500 to over 10 000. Degree of polymerization can influence fibre strength.

Question 4

Fibre Crystallinity:

Answer 4

Polymer chains in the fibre can be configured in crystalline regions or amorphous regions. A typical fibre has both crystalline & amorphous regions.

Question 5

Crystalline Regions:

Answer 5

Small or regular units that allow close, ordered packing of polymer chains that zip together. These chains are held together by polar hydrogen bonds and non-polar Van der Waals bonds.

Question 6

Amorphous Regions:

Answer 6

Large units with bulky side-groups that pack in disordered arrangements in polymer chains. These regions have voids between molecular chains with low inter-chain bonding which allows space for dyes and other treatments.

Question 7

Fibre Orientation:

Answer 7

Molecular chains which are parallel to each other and to the fibre’s lengthwise axis are oriented. A “highly oriented” fibre is when a high proportion of polymers are aligned with the fibre axis.

Question 8

Stretching/Drawing of Fibres:

Answer 8

Used to increase orientation in manufactured fibres, immediately after extrusion. This reduces fibre diameter and increases durability.