Aromatic Polyamides Aramids Beth eilso 392 February 19, 2009
utlie Defiitio / Ivetio Preparatio Physical properties Fiber spiig Applicatios
Aramids Federal Trade ommissio defiitio for aramid fiber: A maufactured fiber i which the fiberformig substace is a log-chai sythetic polyamide i which at least 85% of the amide (---) likages are attached directly betwee two aromatic rigs Ar Ar 2 R Amide Aromatic Aromatic polyamide Ivetio DuPot Morga, Kwolek et. al. Japa, etherlads
hemical Structure omopolymer repeat uits: Ar Ar Ar Ar Ar 1 2 3 AB homopolymers Type 3 AABB homopolymers Types 1 ad 2 opolymers Yag,.. Aromatic igh-stregth Fibers, Wiley: ew York, 1989.
hemical Structure Aromatic uits Backboe: Pedet Groups: X X= Alkyl, Aryl, aloge, Alkoxy, yao, Acetyl, itro Bridgig Uits: X X X = ether, sulfide, sulfoe, ketoe, amie, isopropylidie, ethylee, fumaryl, azo Yag,.. Aromatic igh-stregth Fibers, Wiley: ew York, 1989.
AB omopolymers Preparatio 2 Ar X AABB omopolymers Ar A B + X 2 Ar 2 + X Ar Polycodesatio of diacid halides with X + diamies Solutio polycodesatio Iterfacial polycodesatio Melt or vapor phase polymerizatio X Ar Ar A A B B Li, J.; Sherrigto, J.. Adv. Polym. Sci. 1994, 111, 177.
Solutio Polycodesatio 2 Ar 2 + l Ar l l + Diamie ad diacid chloride DuPot Low temperature Moomer purity ad cocetratio Amide solvet (MP, MPA, DMA) Ar Ar A A B B -methylpyrrolidoe 3 P 3 3 3 3 3 examethylphosphoramide 3 3 3 Dimethylacetamide Li, J.; Sherrigto, J.. Adv. Polym. Sci. 1994, 111, 177.
Solutio Polycodesatio Poly(m-pheylee isophthalamide) omex 2 2 l l + Amide Solvet Kwolek, S. L.; Morga, P. W.; Soreso, R. W. U.S. Patet 1 199 458, ovember 13, 1962. DuPot, 1967
Solutio Polycodesatio Poly(p-pheylee terephthalamide) (PPTA) Kevlar 2 2 + l l MPA/MP 2:1-15 o Lil or al 2 DuPot Bair, Blades, Morga, Kwolek AKZ Leo Vollbracht, Twaro Kwolek, S. L. U.S. Patet 3 819 587, 1974. Blades,. U.S. Patet 3 869 429, 1975. Bair, T. I.; Morga, P. W. U.S. Patet 3 673 143, 1972.
Solutio Polycodesatio igashi sythesis - phosphorus-cotaiig activatig aget Ar P(Ph) 3 / MP/Lil P Ar P Ar' Ar' Ar' Ar' Ar' Ar' Advatages: Elimiates acid chloride startig material a tue reactivity by chagig Ar Ar 2 Ar' 2 Ar' + 2 Ar' + 2 P(Ar') 2 Li, J.; Sherrigto, J.. Adv. Polym. Sci. 1994, 111, 177. dia, G. Priciples of Polymerizatio, 4th Ed. Wiley: ew York, 2004.
Solutio Polycodesatio Silylated diamie with diacid chloride 2 Ar 2 Me 3 Sil SiMe 3 Ar Ar'(l) 2 Me 3 Sil + Me 3 Si Ar Ar' Icreases reactivity of aromatic diamie Faster reactio Elimiatio of Me 3 Sil rather tha l igher molecular weight Li, J.; Sherrigto, J.. Adv. Polym. Sci. 1994, 111, 177.
Solutio Polycodesatio opolymers opolymerizatio of three or more aromatic diamies ad diacid halides. Improved solubility, thermal properties, fiber properties Techora m
Solutio Polycodesatio Summary Preparatio of AABB homopolymers, copolymers Aromatic diamie with diacid halide igh molecular weight Low temperature Moomer stoichiometry, purity, cocetratio Solvet Salt cocetratio Moomer structure (silylated amies) Reagets (triarylphosphites, pyridie)
Physical Properties igh thermal stability (T d 400 ) igh teacity (tesile stregth) hemical resistace Uique solutio properties Low solubility Liquid crystalliity i p-aramids due to chai rigidity Structure depedet Meta vs. para likages Structure of aromatic backboe Yag,.. Aromatic igh-stregth Fibers, Wiley: ew York, 1989. earle, J. S. igh Performace Fibers, Woodhead Publishig Limited: ambridge, 2001.
Liquid rystalliity Liquid crystal substace that has properties of both a solid ad a liquid Thermotropic phase trasitio occurs with temperature chage Lyotropic Liquid crystalliity occurs oly i solutio Varies as a fuctio of polymer cocetratio ad temperature dia, G. Priciples of Polymerizatio, 4 th Ed. Wiley: ew York, 2004.
Liquid rystalliity of p-aramids I solutio of proper cocetratio, liquid crystallie domais form, i which there is a high degree of order of the solute molecules. Para likages result i rod-like exteded chai structure. ydroge bodig rystallizatio from liquid crystal solutios results i polymers with highly ordered exteded-chai morphology Gives rise to polymers with higher stregth ad modulus dia, G. Priciples of Polymerizatio, 4 th Ed. Wiley: ew York, 2004.
Aramid Fiber Spiig Dry-jet Wet Spiig Spiig Solutio 10-20 wt% polymer 100% 2 S 4 ( 2 free) Elogatio aligs crystallie domais Precipitates out of coagulatio bath rystalliity of solutio is traslated to fiber earle, J. S. igh Performace Fibers, Woodhead Publishig Limited: ambridge, 2001.
Properties of Aramid Fibers Teacity ad Modulus Spiig ad drawig coditios Wet vs. dry eat treatmet Polymer compositio Molecular weight Yag,.. Aromatic igh-stregth Fibers, Wiley: ew York, 1989.
Applicatios of Aramids Kevlar http://e.wikipedia.org/wiki/aramid#major_idustrial_uses
Applicatios of Aramids omex Techora m
Applicatios of Aramids earle, J. S. igh Performace Fibers, Woodhead Publishig Limited: ambridge, 2001.