Aromatic Polyamides

Vollbracht, L.

doi:10.1016/b978-0-08-096701-1.00163-4

Cited by 45 publications

(16 citation statements)

References 42 publications

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“…The glass transition temperatures (T g ) of the polymers, as shown by DSC analysis, is in the range of 245-327 • C, being lower than that of related polyamides without pendant groups [2]. Such behaviour of the present polymers could be attributed to the higher free volume determined by the presence of pendant groups.…”

Section: Properties Of the Polymers IV And Vmentioning

confidence: 89%

Poly(1,3,4-oxadiazole-amide)s with pendant acetoxybenzamide or imide groups

Sava¹,

Hamciuc²

2005

Designed Monomers and Polymers

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Two series of aromatic poly(1,3,4-oxadiazole-amide)s containing various pendant groups were synthesized by solution polycondensation of aromatic diamines having preformed 1,3,4-oxadiazole rings with diacid chlorides incorporating acetoxybenzamide, phthalimide or tetrachlorophthalimide side units. These polymers were soluble in polar amidic solvents and gave transparent flexible films. They showed good thermal stability, with initial decomposition temperature being about 300 • C for polyamides with pendant acetoxybenzamide units and 400 • C for the polyamides having pendant phthalimide or tetrachlorophthalimide groups. The glass transition temperatures of the polymers were in the range of 245-327 • C. The polymer films showed the dielectric constant in the range of 3.32-4.90 and good mechanical properties with tensile strength in the range of 35-86 MPa, tensile modulus in the range of 0.235-2.66 GPa and elongation to break in the range of 15-24%. Conformational parameters of the polymers were calculated by using the Monte Carlo method with allowance for hindered rotation. Several physical properties of these polymers such as solubility, glass transition temperature and initial decomposition temperature were measured and discussed in relation with the rigidity of their chains.

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Section: Properties Of the Polymers IV And Vmentioning

confidence: 89%

Poly(1,3,4-oxadiazole-amide)s with pendant acetoxybenzamide or imide groups

Sava¹,

Hamciuc²

2005

Designed Monomers and Polymers

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“…The classic text on the subject is that of MORGAN [90]. Reference to the technique can also be found in [91]. (See also, !…”

Section: Interfacial and Solution Polymerizationmentioning

confidence: 99%

Polyamides

Herzog¹,

Kohan²,

Mestemacher³

et al. 2013

Ullmann's Encyclopedia of Industrial Chemistry

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The article contains sections titled: 1. Introduction 2. Nomenclature 3. General Considerations in Polyamidation 3.1. Molecular Mass 3.2. Equilibrium and Rate Constants 3.3. Effects of Monomer Structure 3.4. Amide Interchange 3.5. Structure‐Property Considerations 4. Other Polymerization Techniques 4.1. Variants of Hydrolytic Polymerization 4.2. Interfacial and Solution Polymerization 4.3. Ionic Polymerization 4.4. Solid‐Phase Polymerization 5. Commercial Processes 5.1. PA 46 5.2. PA 66 5.2.1. Batch Production 5.2.2. Continuous Production 5.3. Other AABB‐Polyamides 5.4. PA 6 5.5. PA 11 5.6. PA 12 6. Properties 6.1. Properties of Unmodified Polyamides 6.2. Copolymerization 6.3. Modification by Additives 6.3.1. Filled and Reinforced Polyamides 6.3.2. Blends and Alloys 6.3.3. Flame‐Retardant Polyamides 6.3.4. Conductive Polyamides 6.3.5. Other Formulations 7. Processing 8. Uses 9. Ecological Aspects and Toxicology 9.1. Recycling 9.2. Polyamide Monomers 9.3. Other Aspects 10. Economic Aspects

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“…1,2 The properties of Lyocell fibers differ from those of other regenerated cellulosic fibers because the raw material of Lyocell fibers is wooden paper pulp (from trees), which dissolves directly in the organic solvent N-methyl morpholine-Noxidote without the formation of cellulose derivatives. Newcell fibers are a kind of Lyocell fibers that are regenerated cellulose fibers, whose chemical structure of cellulose II is identical to that of cellulose fibers.…”

Section: Introductionmentioning

confidence: 98%

Influence of alkali treatment on the structure of newcell fibers

Zhu

Ren

2004

J of Applied Polymer Sci

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Alkali treatment can change the structures and properties of cellulosic fibers. The aim of this work was to study the mechanism of structural changes of Newcell fibers treated with different alkali concentrations and two treatment methods. Raman spectra showed that the molecular conformation of Newcell fibers remained unchanged. X-ray diffraction indicated that the crystal structure of Newcell cellulose II, treated with different alkali concentrations and different methods, did not change. With the increase of alkali concentration the crystallinty and crystallinity orientation index of Newcell fibers in their original length decreased slightly, whereas those of fibers in relaxed condition substantially decreased, and the crystallite size of 101 and 002 increased in both methods. The quasi-crystallite disassociation and recrystallization in the quasi-crystalline phase, during the process of alkali treatment, led to changes of crystallinity and orientation index of Newcell fibers.

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Aromatic Polyamides

Cited by 45 publications

References 42 publications

Poly(1,3,4-oxadiazole-amide)s with pendant acetoxybenzamide or imide groups

Poly(1,3,4-oxadiazole-amide)s with pendant acetoxybenzamide or imide groups

Polyamides

Influence of alkali treatment on the structure of newcell fibers

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