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Rigid-rod Polymers (rigid-rod + polymer)

Distribution by Scientific Domains
Polymers and Materials Science80%

Selected Abstracts

Rigid-Rod Polymers: Synthesis, Processing, Simulation, Structure, and Properties

MACROMOLECULAR MATERIALS & ENGINEERING, Issue 11 2003
Xiao-Dong Hu
Abstract Synthesis, structure, and properties of rigid-rod polymers with special emphasis on poly(p -phenylene benzobisoxazole) (PBO) and poly(p -phenylene benzobisthiazole) (PBZT) have been reviewed. Recent studies on chemical modifications and molecular simulations have also been given. After nearly 20 years of research and development, PBO fiber was commercialized in the late 1990s. However, due to processing difficulties, the concept of the so called molecular composites has not been successful. Development of the high compressive strength M5 and dihydroxy-PBI fibers clearly suggest that there is potential for further developing properties of this class of materials. Opto-electronic properties have also been reviewed. Synthesis of PBZT. [source]

Heat resistance and flammability of high performance fibres: A review

FIRE AND MATERIALS, Issue 4-5 2002
Serge Bourbigot
The heat and flame resistance of high performance fibres are reviewed according to the literature data. The performance is discussed considering the physical and chemical structure of the fibres. Some selected high performance fibres are then evaluated using the cone calorimeter as a fire model to provide realistic data on the fire behaviour of the fibres. They are also examined in terms of heat resistance using combined TGA/DSC. The results are discussed and compared with literature data. Heterocyclic rigid-rod polymers (poly (p-phenylene-2,6-benzobisoxazole or PBO (Zylon®) and poly(2,6-diimidazo (4,5-b:4,,5,-e) pyridinylene-1,4 (2,5-dihydroxy) phenylene or PIPD (M5)) exhibit the best performance (little or contribution to fire, low smoke and good heat resistance) and offer a good combination between heat and flame resistance and mechanical properties. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Rigid-Rod Polymers: Synthesis, Processing, Simulation, Structure, and Properties

MACROMOLECULAR MATERIALS & ENGINEERING, Issue 11 2003
Xiao-Dong Hu
Abstract Synthesis, structure, and properties of rigid-rod polymers with special emphasis on poly(p -phenylene benzobisoxazole) (PBO) and poly(p -phenylene benzobisthiazole) (PBZT) have been reviewed. Recent studies on chemical modifications and molecular simulations have also been given. After nearly 20 years of research and development, PBO fiber was commercialized in the late 1990s. However, due to processing difficulties, the concept of the so called molecular composites has not been successful. Development of the high compressive strength M5 and dihydroxy-PBI fibers clearly suggest that there is potential for further developing properties of this class of materials. Opto-electronic properties have also been reviewed. Synthesis of PBZT. [source]

Diacid architecture effect on the synthesis and microstructure of rigid-rod poly(benzobisthiazole)s

POLYMER INTERNATIONAL, Issue 12 2006
Chien-Fan Chen
Abstract Six poly(benzobisthiazole)s (PBTs) have been synthesized by the solution polycondensation of 2,5-diamino-1,4-benzenedithiol in poly(phosphoric acid) (PPA) with systematically varied diacids to demonstrate the diacid architecture effect of the aromatic heterocyclic rigid-rod polymers. The role of PPA is identified and the effects of phosphorus pentoxide and water on PBT during polycondensation are discussed. Polymer properties such as the inherent viscosity and decomposition temperature are correlated to the diacid chemistry. The effect of diacid architecture on the synthesis and microstructure of PBT is studied. The results are discussed in terms of resonance, symmetry, and solubilization of the diacids. Copyright © 2006 Society of Chemical Industry [source]

Photodegradation mechanism and stabilization of polyphenylene oxide and rigid-rod polymers

POLYMER INTERNATIONAL, Issue 2 2006
Ying-Hung So
Abstract Poly(2,4-dimethyl-1,4-phenylene oxide) (PPO), poly(benzo[1,2- d:5,4- d,]bisoxazole-2,6-diyl-1,4-phenylene) (PBO) and poly(benzo[1,2- d:4,5- d,]bisthiazole-2,6-diyl-1,4-phenylene) (PBZT), which are polymers with extended conjugated structures, undergo a self-sensitized photo-induced electron-transfer reaction. A second component is not required. This article presents many similar observations on these polymers when they are exposed to light and evidence to support the proposed photo-induced electron-transfer mechanism. Methods to stabilize these polymers against photo-oxidation are also described. Workers investigating other conjugated polymeric systems may find the experimental methods, observations and polymer stabilization approaches discussed in this review useful. Copyright © 2005 Society of Chemical Industry [source]