Synthesis and Properties of Novel Cardo Aromatic Poly(ether oxadiazole)s and Poly(ether-amide oxadiazole)s

Hsiao, Sheng‐Huei; He, Ming-Hsiang

doi:10.1002/1521-3935(20011201)202:18<3579::aid-macp3579>3.0.co;2-o

Cited by 19 publications

(6 citation statements)

References 16 publications

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“…41 –43 The resulting 1,3,4-oxadiazole containing polyamides were found to be thermally stable and could be rightfully classified in the category of highly thermally stable polymers. 30,44 –47…”

Section: Structure–property Relationships Of Wholly Aromatic Pahsmentioning

confidence: 99%

High-performance wholly aromatic polyamide–hydrazides

Elsabeé

Morsi

Selim³

2017

High Performance Polymers

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The review summarizes the various methods of preparing wholly aromatic polyamide–hydrazides (PAHs). Polyhydrazides are a class of polymers that possess in their repeating units one amide (–NHOC–) and one hydrazide (–CONHNHOC–) linking bond between appropriate aromatic nuclei. The review provides several figures of different molecular structures of PAH and expounds the methods of polymerization, low, high temperature, and phosphorylation polycondensation methods. Polyhydrazides exhibit some unique and potentially useful properties such as outstanding thermal and thermo-oxidative resistance, very high mechanical strength, and ultrahigh moduli. PAHs undergo structural transformation into poly(amide-1,3,4-oxadiazole)s upon heating, which are also considered highly thermally stable polymers. The review presents a description of the structure–property relation of PAHs. The application of PAHs in reverse osmosis applications has been discussed, as well as the preparation of fibers and metallized PAHs films. Modification of the PAH with carbon nanotubes and graphene and the future prospects for PAHs were introduced with comprehensive references pertaining to this area of research.

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Section: Structure–property Relationships Of Wholly Aromatic Pahsmentioning

confidence: 99%

High-performance wholly aromatic polyamide–hydrazides

Elsabeé

Morsi

Selim³

2017

High Performance Polymers

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“…The inclusion of flexible side chains or flexible linkages in the backbone via appropriately designed monomers has been demonstrated to be an effective approach to enhance processability characteritics of poly (1,3,4-oxadiazole)s. 9,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] These structural features bring about reduction in interchain interactions and decrease internal energy of rotation leading to lowering of thermal transition temperatures (T g and T m ).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of polyhydrazides and poly(1,3,4-oxadiazole)s containing multiple arylene ether linkages and pendent pentadecyl chains

Tawade

Valsange

Wadgaonkar

2016

High Performance Polymers

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A new diacylhydrazide monomer, namely, 4-(4-(4-(4-(hydrazinocarbonyl)phenoxy)-2-pentadecylphenoxy)phenoxy) benzohydrazide (HPPDPB), was synthesized starting from 4-(4-hydroxyphenoxy)-3-pentadecylphenol. HPPDPB was polycondensed with terephthalic acid chloride (TPC), isophthalic acid chloride (IPC) and a mixture of TPC and IPC (50:50 mol%) to obtain polyhydrazides containing multiple arylene ether linkages in the backbone and pendent pentadecyl chains. Polyhydrazides were subsequently cyclized in the presence of phosphorus oxychloride to obtain the corresponding poly(1,3,4-oxadiazole)s. Polyhydrazides and poly(1,3,4-oxadiazole)s exhibited inherent viscosities in the range 0.65–0.72 dL g−1 and 0.54–0.62 dL g−1, respectively, which indicated the formation of reasonably high-molecular weight polymers. Polyhydrazides were soluble in polar aprotic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidinone and pyridine whereas poly(1,3,4-oxadiazole)s exhibited excellent solubility even in common organic solvents such as chloroform, dichloromethane and tetrahydrofuran. Tough, transparent and flexible films of polyhydrazides and poly(1,3,4-oxadiazole)s could be cast from DMAc and chloroform solutions, respectively. X-Ray diffraction studies revealed amorphous nature of polyhydrazides and poly(1,3,4-oxadiazole)s and the formation of layered structure was observed due to ordered packing of pentadecyl chains. The 10% decomposition temperature ( T10) values for poly(1,3,4-oxadiazole)s were in the range 425–440°C indicating their good thermal stability. Glass transition temperature ( Tg) values of polyhydrazides and poly(1,3,4-oxadiazole)s were in the range 175–192°C and 92–103°C, respectively. The excellent solubility characteristics and the large gap between Tg (92–103°C) and T10 (425–440°C) values give poly(1,3,4-oxadiazole)-containing pendent pentadecyl chains better opportunities for processability.

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“…The conventional aromatic poly(1,3,4‐oxadiazole)s are difficult to process due to their infusible and insoluble nature and their tendency to be brittle. Many efforts have been made to improve the solubility, viz , by incorporation of flexible linkages in the polymer backbone or by incorporation of bulky pendant groups on the aromatic rings 16–30. Among various strategies adopted to improve processability of poly(1,3,4‐oxadiazole)s, the incorporation of long and flexible side chains has proven satisfactory 14, 31, 32.…”

Section: Introductionmentioning

confidence: 99%

New poly(1,3,4‐oxadiazole)s bearing pentadecyl side chains: Synthesis and characterization

Menon

Wadgaonkar

2011

J of Applied Polymer Sci

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The 4-[4 0 -(Hydrazinocarbonyl)phenoxy]-2-pentadecylbenzohydrazide was polycondensed with aromatic diacid chlorides viz., terephthalic acid chloride (TPC), isophthalic acid chloride (IPC), and a mixture of TPC : IPC (50 : 50 mol %) to obtain polyhydrazides which on subsequent cyclodehydration reaction in the presence of phosphoryl chloride yielded new poly(1,3,4-oxadiazole)s bearing flexibilizing ether linkages and pentadecyl side chains. Inherent viscosities of polyhydrazides and poly(1,3,4-oxadiazole)s were in the range 0.53-0.66 dL g À1 and 0.49-0.53 dL g À1, respectively, indicating formation of medium to reasonably high molecular weight polymers. The number average molecular weights (M n ) and polydispersities (M w /M n ) of poly(1,3,4-oxadiazole)s were in the range 14,660-21,370 and 2.2-2.5, respectively. Polyhydrazides and poly(1,3,4-oxadiazole)s were soluble in polar aprotic solvents such as N,N-dimethylacetamide, 1-methyl-2-pyrrolidinone, and N,N-dimethylformamide. Furthermore, poly(1,3,4-oxadiazole)s were also found to be soluble in solvents such as chloroform, dichloromethane, tetrahydrofuran, pyridine, and m-cresol. Transparent, flexible, and tough films of polyhydrazides and poly(1,3,4-oxadiazole)s could be cast from N,N-dimethylacetamide and chloroform solutions, respectively. Both polyhydrazides and poly(1,3,4-oxadiazole)s were amorphous in nature and formation of layered structure was observed due to packing of pentadecyl chains. A decrease in glass transition temperature was observed both in polyhydrazides (143-166 C) and poly(1,3,4-oxadiazole)s (90-102 C) which could be ascribed to ''internal plasticization'' effect of pentadecyl chains. The T 10 values, obtained from TG curves, for poly(1,3,4-oxadiazole)s were in the range of 433-449 C indicating their good thermal stability.

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Synthesis and Properties of Novel Cardo Aromatic Poly(ether oxadiazole)s and Poly(ether-amide oxadiazole)s

Cited by 19 publications

References 16 publications

High-performance wholly aromatic polyamide–hydrazides

High-performance wholly aromatic polyamide–hydrazides

Synthesis and characterization of polyhydrazides and poly(1,3,4-oxadiazole)s containing multiple arylene ether linkages and pendent pentadecyl chains

New poly(1,3,4‐oxadiazole)s bearing pentadecyl side chains: Synthesis and characterization

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