Requirement of fiber formation or fiber forming polymer:
1) Polymer should have long & linear chain molecules.
2) They must be chemically resistance.
3) Molecular chain must be parallel to each other.
4) They should have attractions.
5) Some measures of freedoms of molecules movement due to give required extensibility.
6) Lateral forces to hold the molecules together and gives cohesion the structure.
Methods of fiber structure investigation:
1) X-ray diffraction method
2) Infra-red radiation method
3) Electron microscopic method
4) Optical microscopic method
5) Thermal analysis
6) Nuclear magnetic resonance methods
7) Density
9) The chemistry of fiber material
Properties of x-ray diffraction method:
1) Determination of chemical groups
2) Determination of molecular spacing
3) Determination of chemical bonding
4) Determination of degree of crystallinity & orientation
5) Determination of water absorption
Properties of Infra- red radiation absorption method:
1) Determination of spiral turns or convolution of cotton fiber
2) Determination of molecular spacing
3) Determination of chemical bonding
4) Determination of degree of crystallinity & orientation
5) Determination of molecular packing
6) Determination of cross-sectional shape of fiber
7) Identifications of fiber
Crystallinity:
Crystallinity is the arrangement of fiber molecules in the molecular chain.
Properties of crystallinity:
Properties of crystallinity:
1) More dense
2) More stiff
3) More strength
4) More rigid
5) Less water absorbent
Measurement of crystallinity:
1) X-ray diffraction method
2) Infra-red radiation absorption method
3) Density measurement methods
Orientation: Orientation is the arrangement of molecular chain of fiber.
Properties of Orientation:
Orientation: Orientation is the arrangement of molecular chain of fiber.
Properties of Orientation:
1) More dense
2) More stiff
3) More strength
4) More rigid
5) More water absorbent
6) More lustrous
7) Less elastic as less extension
Measurement of Orientation:
1) X-ray diffraction method
2) Infra-red radiation absorption method
3) Density measurement methods
Effects of structural factors on fiber properties:
1) Chemical bonding:
a) Single bond-More strength, less flexibility
b) Double bond - Less strength, more flexibility
2) Character of polymer chin:
a) Long chain, such as [-CH2-CH2-CH2-CH2-CH2-CH2-]n-More strength, less flexibility
b) Sort chain, such as [-CH2-CH2-]n-Les strength, more flexibility
b) Sort chain, such as [-CH2-CH2-]n-Les strength, more flexibility
c) Long side chain-More strength, less flexibility
d) Sort side chain-Less strength, more flexibility
d) Sort side chain-Less strength, more flexibility
3) Molecular packing:
a) Regular packing: More strength, less flexibility
b) Irregular packing: Less strength, more flexibility
b) Irregular packing: Less strength, more flexibility
4) Crystallinity: High crystallinity, higher strength and less flexibility
5) Orientation: High Orientation, higher strength and less flexibility
6) Nature of monomer:
a) Same monomer (Homopolymer) -More strength, less flexibility
b) Same monomer (Co-polymer) -Less strength, more flexibility
b) Same monomer (Co-polymer) -Less strength, more flexibility
7) Internal structure of fiber polymer:
a) For ring structure -More strength, less flexibility
b) For normal structure -Less strength, more flexibility
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