Chapter 15 Acetate and Triacetate Fibers Yiping Qiu 是 Donghua University
Chapter 15 Acetate and Triacetate Fibers Yiping Qiu Donghua University
Introduction Fibers in which forming substance is cellulose acetate where not less than 92%o of hydroxyl groups are acetylated: replacing -OH groups with COCH3 Acetate: 2 of 3-OH groups in each 6-member ring are acetylated: 2.5 Triacetate: Nearly all -OH groups are replaced 2.91~2.96 Major use: lining fabrics for suits, coats, draperies
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; ~2.5 • Triacetate: Nearly all -OH groups are replaced 2.91~2.96 • 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
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 onl Swells in water, mechanical properties change in water Resist to weak alkali and acids Can be bleached
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
Properties • Soluble in acetone • Degrade in UV light • Burns, melts, forms black beads with vinegar like odder