Thermal and structural analysis and crystallization behavior of new poly(ether‐alkyl) oxadiazoles

Pace, Emilia Di; Fichera, Annamaria; Laurienzo, Paola; Malinconico, Mario; Martuscelli, E.; Perenze, Nicoletta; Volpe, Maria Grazia

doi:10.1002/polb.1994.090320907

J Polym Sci B Polym Phys

1994

DOI: 10.1002/polb.1994.090320907

|View full text |Cite

Thermal and structural analysis and crystallization behavior of new poly(ether‐alkyl) oxadiazoles

Emilia Di Pace¹,

Annamaria Fichera²,

Paola Laurienzo³

et al.

Abstract: A new series of poly(ether‐alkyl)oxadiazoles of general formula: with m = 3, 4, and 5 has been obtained from the corresponding polyhydrazides through thermal cyclization reaction. The polymers were characterized by infrared spectroscopy, differential scanning calorimetry, wide‐angle x‐ray analysis, and optical microscopy. The polymers were crystalline, with a crystalline texture and structural parameters strongly dependent on the value of m. The Tm's and Tg's value decreased with increasing number of CH2. © 1… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2001

2015

Publication Types

Select...

Article4

Relationship

Self Cite0

Independent4

Authors

Journals

Cited by 4 publications

(1 citation statement)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We found that the insertion of mesogenic units containing short methylenic sequences lowers T m giving rise to a window of processability compatible with that of more common polyesters and polyamides, while keeping a still high T g . 10 Unfortunately, the resulting polymers did not show any stable mesophase in the melt, which would further improve their processability, as occurs in the case of liquid crystalline thermotropic polyesters.…”

mentioning

confidence: 99%

A New Class of Poly(ester hydrazide) Copolymers with Liquid Crystalline Properties. Synthesis and Characterization

Capitani¹,

Prisco²,

Laurienzo³

et al. 2001

Polym J

View full text Add to dashboard Cite

ABSTRACT:A series of copolyesters (PE) of low molecular weight containing propyloxy-substituted aromatic ring and/or ethylenic sequences between aromatic units were prepared by melt polycondensation between corresponding diacids and diacetates, and used as precursor of poly(ester-co-polyhydrazide) (PEH) new copolymers. The PEs showed to have thermotropic properties, with transition temperatures which depend on the chemical composition and with a good interval of stability of the mesophase. The corresponding PEHs were obtained by high-temperature polycondensation of carboxyl-terminated PEs with terephthalic dihydrazide. The PEHs showed as well a stable mesophase in the melt, and improved thermal stability respect to polyesters. All the polymers were characterized by elemental analysis, inherent viscosity, infrared and 13 C solid state NMR spectroscopy, thermal and thermogravimetric analysis and optical microscopy. Fibers of PEHs were obtained by melt-spinning and characterized by WAXS analysis.KEY WORDS Liquid Crystallinity / Copolymers / Polyester / Polyhydrazide / Fiber / In the last decades, many efforts have been pointed on the synthesis of rigid-chains polymers with high heat resistance and good mechanical properties for extreme environment applications. [1][2][3][4][5][6] Heat resistant polymers are defined as organic materials which maintain their mechanical characteristics at T > 300 • C for several days or hours. Such temperatures can be reached during manufacturing or utilization of products. 7 Polyhydrazides and their polyoxadiazole derivatives, polyimides, polybenzoxazoles, and polybenzothiazoles are classified as heat-resistant polymers. At early, scarce attention was paid to their processability, and so to real possibilities of application. More recently, then, research on heat-resistant polymers is directed to improve processing window. In fact, the characteristics which render these polymers attractive for utilization in severe conditions are the same which make them hard to process: high melting temperatures (sometimes above decomposition temperature), high melt viscosity and low solubility.Aromatic polyhydrazides 8, 9 have recently attracted our attention. They are obtained from the reaction between aromatic diacids and dihydrazides, and are viewed as precursor of much more stable aromatic polyoxadiazoles, in the same way as polyamic acids are precursor of polyimides. We found that the insertion of mesogenic units containing short methylenic sequences lowers T m giving rise to a window of processability compatible with that of more common polyesters and polyamides, while keeping a still high T g . 10 Unfortunately, the resulting polymers did not show any stable mesophase in the melt, which would further improve their processability, as occurs in the case of liquid crystalline thermotropic polyesters.Liquid crystalline polymers are characterized by low melt viscosity and their fibers show excellent mechanical properties with stiffness close to theoretical values. A very well known class of thermo...

show abstract

mentioning

confidence: 99%

A New Class of Poly(ester hydrazide) Copolymers with Liquid Crystalline Properties. Synthesis and Characterization

Capitani¹,

Prisco²,

Laurienzo³

et al. 2001

Polym J

View full text Add to dashboard Cite

show abstract

Preparation and evaluation of sulfonated polyoxadiazole membrane containing phenol moiety for PEMFC application

Abdolmaleki

Zhiani

Maleki

et al. 2015

Polymer

View full text Add to dashboard Cite

Synthesis and characterization of new sulfonated poly(arylene ether 1,3,4-oxadiazole)s

Vetter

Nunes

2004

Reactive and Functional Polymers

View full text Add to dashboard Cite

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Thermal and structural analysis and crystallization behavior of new poly(ether‐alkyl) oxadiazoles

Cited by 4 publications

References 6 publications

A New Class of Poly(ester hydrazide) Copolymers with Liquid Crystalline Properties. Synthesis and Characterization

A New Class of Poly(ester hydrazide) Copolymers with Liquid Crystalline Properties. Synthesis and Characterization

Preparation and evaluation of sulfonated polyoxadiazole membrane containing phenol moiety for PEMFC application

Synthesis and characterization of new sulfonated poly(arylene ether 1,3,4-oxadiazole)s

Contact Info

Product

Resources

About