Molecular design and synthesis of thermotropic liquid crystalline poly(amide imide)s with high thermal stability and solubility

e-Polymers ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Yanbin Wang ◽  
Guangming Lu ◽  
Wenjie Wang ◽  
Meng Cao ◽  
Zhonglin Luo ◽  
...  

AbstractA series of thermotropic liquid crystalline poly(amide imide)s (PAIs) with well-defined structure were prepared by the Yamazaki-Higashi phosphorylation method. To obtain the target polymers, several diimide diacid monomers (DIDAs) as mesogenic units were synthesized by the dehydration cyclization of aromatic anhydride with aliphatic 11-aminoundecanoic acid (AU). The chemical structure of these DIDAs and PAIs was confirmed via Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. Thermotropic liquid crystalline characteristics of the DIDAs and PAIs were investigated by differential scanning calorimetry (DSC), polarizing light microscopy (PLM) and X-ray diffraction (XRD) analysis. Encouragingly, all of these liquid crystalline PAIs exhibited good thermal stability, in which the decomposition temperatures are much higher than the melting temperatures of PAIs. Furthermore, the liquid crystalline PAIs can be dissolved into some common solvents such as dimethyl sulfoxide (DMSO) and m-cresol, which indicates these liquid crystalline PAIs could be processed not only by melting-processing but also by solution spin-coating.

2003 ◽  
Vol 15 (3) ◽  
pp. 301-318 ◽  
Author(s):  
Vasile Cozan ◽  
Mitica Sava ◽  
Luminita Marin ◽  
Maria Bruma

Six new bismaleimides (BMIs) having arylidene or cardo cycloaliphatic internal moieties were prepared by reacting 4-maleimidobenzoyl chloride with various arylidene or cardo bisphenols. The structures of BMIs were confirmed using elemental analysis data and spectroscopic (IR, 1H-NMR) characterizations. Two poly(aminoaspartimide)s (PAAs) were synthesized to exemplify one of the post-reaction abilities of the BMIs. Thermotropic liquid crystalline behavior was observed by differential scanning calorimetry and polarized light microscopy. The thermal stability of BMIs and PAAs was determined by thermogravimetric analysis and they showed good thermal stability except BMI 10, containing a cyclopentanone unit, which decomposed around 235°C. In this paper, we discuss the synthesis and characterization of these materials.


2017 ◽  
Vol 30 (4) ◽  
pp. 475-479 ◽  
Author(s):  
Wenxuan Wei ◽  
Li Yang ◽  
Guanjun Chang

Indole-based poly(ether sulfone)s (PINESs), as novel high-performance polymers, have been obtained by the condensation polymerization of 4-hydroxyindole and hydroquinone with activated difluoro monomers via a catalyst-free nucleophilic substitution reaction. The structures of the polymers are characterized by means of Fourier transform infrared and proton nuclear magnetic resonance spectroscopy, and the results show good agreement with the proposed structures. Differential scanning calorimetry and thermogravimetric analysis measurements exhibit that polymers possess high glass transition temperature ( Tgs > 245°C) and good thermal stability with high decomposition temperatures ( Tds > 440°C). In addition, due to their special structure, PINESs are endowed with significantly strong photonic luminescence in N, N-dimethylformamide.


2016 ◽  
Vol 29 (10) ◽  
pp. 1139-1147 ◽  
Author(s):  
Zi Sang ◽  
Tiantian Feng ◽  
Wenbin Liu ◽  
Jun Wang ◽  
Mehdi Derradji

A new series of aniline and aniline-mixed tetrafunctional fluorene-based oxazine monomers were synthesized using 2,7-hydroxy-9,9-bis-(4-hydroxyphenyl) fluorene, paraformaldehyde, and primary amines (including aniline or aniline mixed with n-butylamine or n-octylamine composition). Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy were used to characterize the structure of the monomers. The copolymers were obtained by adding the monomers into a typical monofunctional polybenzoxazine (phenol-aniline-based benzoxazine). Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were performed to study the thermal properties of the copolymers. The copolymers exhibited high glass transition temperature values (164–201°C). A good thermal stability was also obtained with a 5% weight loss temperature over 355°C and high char yields at 800°C (42–50%).


2019 ◽  
Vol 52 (6) ◽  
pp. 483-494 ◽  
Author(s):  
Wenzheng Zhang ◽  
Ning Jiang ◽  
Tingting Zhang

The sustainable biomass cardanol grafting onto neoprene (CR) rubber was carried out successfully at room temperature by covalently binding to CR via click chemistry to realize the internal plasticization of CR rubber. The structure of the synthesized product was characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance, and differential scanning calorimetry and thermogravimetric analysis demonstrate a lowering of the glass transition temperature of the CR-propargyl ether cardanol as compared to CR. This confirms the plasticization effect of the cardanol when grafted onto CR. The cardanol as an internal plasticizer also has a good thermal stability and almost near-zero migration.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Moslem Mansour Lakouraj ◽  
Vahid Hasantabar ◽  
Nazanin Bagheri

A series of linear aromatic polyethers containing triazole units were synthesized via the direct click reaction of dibromide and bisethynyl compounds in the presence of sodium azide as one pot reaction. The structures of polymers were approved by using IR and 1H NMR techniques. The solubility experiments showed that polymers have good solubility in polar aprotic solvents such as DMSO, DMF, and NMP at higher temperatures. Thermal stability of the polymers was measured using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) which indicated that they possessed good thermal stability ( up to 558°C) and high (191.7–260°C) under N2 atmosphere. All the polymers were amorphous according to the DSC and X-ray diffraction. These polymers exhibited strong UV-vis absorption maxima near to 400 nm and up to 500 nm in DMSO solution.


2021 ◽  
pp. 095400832199674
Author(s):  
Tao Guo ◽  
Yang Fan ◽  
Chang Bo ◽  
Zhang Qi ◽  
Han Tao ◽  
...  

Benzoxazine resin exhibits excellent properties and is widely used in many fields. Herein, the synthesis of a novel compound, the bis(2,4-dihydro-2 H-3-(4- N-maleimido)phenyl-1,3-benzoxazinyl)biphenyl (BMIPBB), has been reported, which was synthesized by reacting N-(4-aminophenyl)maleimide (APMI), formaldehyde, and 4,4’-dihydroxybiphenyl. 1,3,5-three(4-(maleimido)phenyl)-1,3,5-triazine (TMIPT) was formed as an intermediate during the reaction. The proton nuclear magnetic resonance (1H-NMR) and Fourier transform-infrared (FTIR) spectroscopy experiments were conducted to determine the structure of BMIPBB. BMIPBB was obtained as a reddish-brown solid in 40.1% yield. The thermal properties of BMIPBB were investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. Analysis of the DSC curves revealed that the broad peak representing the release of curing reaction heat appeared in the temperature range of 140–330°C. The peak temperature was 242.59°C and the heat of the reaction was 393.82 J/g, indicating that the rate of the curing reaction was low and the heat of the reaction was high. Analysis of the TGA results revealed that the weight loss rate was 5% at 110°C. The monomer exhibited a significant weight loss in the range of 320–500°C. The compound lost 50% of its weight at a temperature of 427°C.


e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.


2011 ◽  
Vol 197-198 ◽  
pp. 1332-1336 ◽  
Author(s):  
Zhi Yi Huang ◽  
Shao Rong Lu ◽  
Zhi You Yang ◽  
Dong Guo ◽  
Chong Xi Luo

A series of novel liquid crystal polyurethanes containing biphenylnate and imide units were synthesized through the polyaddition reaction of 4,4′-Bis-(2-hydroxyhexoxy)biphenyl (BP2), 2,4-toluenediisocyanate (2,4-TDI) with N,N′-bis(2-hydroxyhexyl)-dicarboxyimide (BHDI) by altering the molar ratio of BP2 and BHDI. The effects of structure difference molar ratio between BP2 and BHDI on the liquid crystalline behavior and thermal stability were studied. Results showed that all of the polyurethane polymers exhibited thermotropic nematic liquid crystalline textures in the range of 160~190°C. The melting temperatures (Tm) and the thermal stability increased with increasing BHDI content.


2001 ◽  
Vol 665 ◽  
Author(s):  
Zhi-Kuan Chen ◽  
Nancy Hoi Sim Lee ◽  
Wei Huang

ABSTRACTWe report the synthesis and characterization of a novel series of aryl-substituted PPVs, which have shown excellent processability, good thermal stability, high photoluminescence quantum efficiency and low content of structural defects. The substituents of the polymers were designed with different degree of hindrance effect on the main chain. 1H NMR measurement indicates that the defect structure in the polymer main chain can be effectively depressed by introducing bulk and hindrance substituents.


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