Unit 2 - Lecture 11 Topic 2 Flashcards
Nylon History:
The first synthetic fibre developed in the US. DuPont, in the mid-late 1930s / early 1940s named Nylon, and used it for: Toothbrushes and hosiery. In WWII it was used for ropes, sails, parachutes. There was a polyamide generic fibre in the UK & Europe and Canada.
Nylon:
A long chain synthetic polyamide that has recurring amide groups as an integral part of the main polymer chain in which at least 85% by mass of the amide
linkages are attached to aliphatic or cycloaliphatic
groups. Most notably is the amide link between the CO – NH. Common types: nylon 6 and nylon 6,6.
Nylon 6 vs Nylon 6,6:
Nylon 6: Six repeating carbons between the NH and the CO
Nylon 6,6: Six repeating carbons between the NH and then six repeating carbons, two of which are CO
What is the chemical make up of nylon like?
Nylon is a polyamide, meaning it has recurring amide groups and long molecular chains. Nylon is chemically related to protein fibres with similar dye sites that use the same types of dyes as protein fibres.
What is the cross sectional shape of nylon?
Cross-sectional shape is round, with a smooth
surface, but the shape can be varied.
How are nylon polymer chains formulated?
The polymer chains are linear zig-zag configuration so they can pack closely together, making them highly crystalline fibres. Hydrogen bonds form between the C=O & H–N along adjacent polymers.
What can the ends of nylon fibres be used for?
Interior: Carpeting, upholstery
Apparel: Hoisery, jacket lining, swimwear
Technical: Tire cords, car interiors, ropes, performance apparel, sporting goods
What is nylon strength and elongation?
Uniquely high.
What is nylon tenacity like?
Nylon has regular tenacity for the apparel market and high tenacity for the industrial and carpet market. High tenacity nylon is drawn more to increase crystallinity, orientation and strength. This strength is due to high crystalline polymer structure and contains hydrogen bonds.
What is nylon elongation, elastic recovery, and resiliency like?
High. When longitudinal force is applied, the zig-zag polymers are straightened. The grid of H-bonds help prevent slippage (to a point – severe stress will break H-bonds). High tenacity nylon fibres lower elongation due to increased crystallinity and orientation. Nylon’s resiliency can recover from bending, stretching or compression.
What is the abrasion resistance of nylon like?
Nylon has excellent abrasion resistance. It can withstand a lot of rubbing, flexing etc. which is why it is often used as a reinforcement fibre in blends (eg, cotton or wool socks). High tenacity, resiliency & abrasion resistance makes nylon excellent for carpets.
How well does nylon resist sunlight, chemicals, insects and microorganisms?
Nylon has low resistance to sunlight– although typically better than protein fibres, but it is resistant to chemicals, insects and microorganisms.
How does nylon feel to touch?
Smooth and silky.
What is the moisture absorption of nylon like?
Nylon has the highest moisture regain of synthetic fibres (~4%). Absorption happens at the polar sites of amide groups, but is limited by nylon’s crystalline structure. It’s also static prone.
What is the air and water permeability like in nylon?
Nylon fibre’s round, smooth rod shape allows close packing of fibres in yarns, and of the yarns in fabric. As a result, nylon is used in wind-proof clothing and equipment. Its air permeability and water vapour permeability can be improved by adding a mechanical crimp as well.
