文档介绍：Chapter 15 Acetate and Triacetate Fibers
Introduction
Fibers in which forming substance is cellulose acetate where not less than 92% of hydroxyl groups are acetylated: replacing -OH groups with -COCH3.
Acetate: 2 of 3 -OH groups in each 6-member ring are acetylated; ~
Triacetate: Nearly all -OH groups are replaced ~
Major use: lining fabrics for suits, coats, draperies
Structures
Surface: straited
Cross-section: lobed
Skin-core structure
DP: 250-300
Much less H-bond than in rayon
Properties
Acetate: hydrophilic, thermoplastic
Triacetate: hydrophobic, higher melting and softening temperature, high crystallinity
Wrinkle easily in hot water: dry cleaning only
Swells in water, mechanical properties change in water
Resist to weak alkali and acids
Can be bleached
Properties
Soluble in acetone
Degrade in UV light
Burns, melts, forms black beads with vinegar like odder
Production
Similar to cellulose rayon for the first a few steps
Cellulose mixed with acetic acid and acetic anhydride, a sulfuric acid catalyst is added
acetylation takes place
degradation of the polymer making DP low
triacetate is made first
when water added, some acetyl groups are removed
Grades for test 1
Chapter 16 Nylon Fibers
Introduction
Nylon: man-made fibers in which fiber forming substance is any long-chain synthetic polyamide in which less than 85% of the amide linkages are attached to 2 aromatic rings
Invented in 1938 in Du Pont
Largest market: carpet fiber 80% of market
14% industrial and consumer products: tire cord, fabrics and ropes
11% apparel
Introduction
Types:
Mostly: Nylon 6 and Nylon 6,6
Small amount: nylon 3, nylon 4, nylon 5, nylon 7, nylon 8, nylon 12, nylon 4,6, nylon 6,10