Thermal properties of a series of tetrafunctional fluorene-based oxazines/P-a blends

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%).

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.


Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2636
Author(s):  
Tomasz M. Majka ◽  
Oskar Bartyzel ◽  
Konstantinos N. Raftopoulos ◽  
Joanna Pagacz ◽  
Krzysztof Pielichowski

Pyrolysis of the polypropylene/montmorillonite (PP/OMMT) nanocomposites allows for recovery of the filler that can be then re–used to produce PP/pyrolyzed MMT (PMMT) nanostructured composites. In this work, we discuss the thermal properties of PP/PMMT composites investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It has been found that effect of PMMT (5 wt. % and 10 wt. %) on matrix thermal stability occurs at temperatures above 300 °C. Addition of 5 wt. % and 10 wt. % of PMMT into polypropylene system gave good stabilization effect, as confirmed by the overall stabilization effect (OSE) values, which increased by 4% and 7%, respectively, compared to the control sample (PP). Interestingly, the presence of 1 wt. % and 3 wt. % of pyrolyzed clay stabilizes the system better than the same concentrations of organoclay added into polypropylene melt. DSC data revealed that pyrolyzed clay has still the same tendency as organoclay to enhance formation of the α and β crystalline PP phases only. The pyrolyzed MMT causes an improvement of the modulus in the glassy as well as rubbery regions, as confirmed by DMA results.


e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Lin Zhang ◽  
Guanjun Chang ◽  
Zhen Xu ◽  
Lubin Miao ◽  
Yi Xu ◽  
...  

AbstractA series of novel poly(arylene imino) containing fluorenone group (PIKF) have been synthesized via palladium-catalyzed polycondensation. The thermal properties of PIKF are detected by thermal behavior (TG) and differential scanning calorimetry (DSC). UV-vis absorption spectra, photoluminescence are investigated. PIKF exhibit good thermal stability and high Tgs(>200 °C ). The optical properties of PIKF show that PIKF are interesting materials for further investigations to be presented as possible candidates for use as an electron transport layer (n-type) in multilayer LEDs.


2017 ◽  
Vol 30 (7) ◽  
pp. 840-846 ◽  
Author(s):  
Jafar Rezania ◽  
Abbas Shockravi ◽  
Morteza Ehsani ◽  
Vahid Vatanpour

Three new organic-soluble polyimides (PIs) bearing flexible thioether linkages, thiazole, and pyridine ring units were synthesized from a novel thioether-bridged diamine monomer and commercially available aromatic dianhydrides (1–3) via chemical imidization method. The resulting polymers were obtained in high yields and possessed inherent viscosities in the range of 0.67–0.89. The PIs are characterized by Fourier-transform infrared (FTIR), nuclear magnetic resonance (NMR), differential scanning calorimetry, and thermogravimetric analysis (TGA). All of the PIs exhibited excellent solubility in polar solvent. The polymers showed good thermal stability with glass transition temperatures ( Tgs) in the range of 194–244°C, and decomposition temperatures ( T5%) exceeding 300°C were observed using TGA in nitrogen atmosphere for the current polymers.


1992 ◽  
Vol 4 (2) ◽  
pp. 67-71
Author(s):  
N. R. Patel ◽  
N. Z. Patel ◽  
R. M. Patel

Unsaturated polyamides were prepared by condensing /3(4-ethoxyphenyl) glutaconic acid with various aromatic diamines. The polycondensates were characterized by IR spectroscopy, vapor phase osmometry, thermogravimetric analysis, differential scanning calorimetry and elemental analysis. All resins were found to decompose in the range '-210-600 °C. The kinetics of decomposition were studied. The results indicated that the resins possess reasonably good thermal stability.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3171-3185
Author(s):  
Perry Law Nyuk Khui ◽  
Rezaur Rahman ◽  
Abu Saleh Ahmed ◽  
Kuok King Kuok ◽  
Muhammad Khusairy Bin Bakri ◽  
...  

The morphological and thermal properties of composites containing a bioplastic blend and micro/nano-sized biochar from pyrolyzed jatropha seeds from microwave pyrolyzed jatropha seeds were investigated using scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The biocomposite samples exhibited a brittle structure with a slightly ductile chip-like appearance. The Fourier transform infrared spectroscopy results for the PLA/PEMA/BC bio-composites were comparable to the PLA/BC biocomposites. A lower bio-filler content had more pronounced peak intensities than the higher bio-filler content biocomposites. The added PEMA compatibilizer in the PLA/PEMA/BC biocomposite showed more pronounced peaks, which indicated slightly improved bonding/interaction between the bio-filler and the matrix. Overall, increasing bio-filler content did not drastically affect the functional groups of the biocomposites. Thermogravimetric and differential scanning calorimetry analysis showed the developed biocomposites had a slight improvement in thermal stability, in comparison to the PLA sample. Improvements in the thermal stability of the PLA/PEMA/BC biocomposite could be attributed to the additional hydroxyl group, which was due to the added PEMA in the PLA and PLA/BC. According to the results of the analysis of the developed biocomposites, the biocomposites were more brittle and had reasonable thermal stability.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2433
Author(s):  
Paweł Groch ◽  
Anna Bihun-Kisiel ◽  
Aleksandra Piontek ◽  
Wioletta Ochędzan-Siodłak

The series of ethylene-norbornene (E-NB) copolymers was obtained using different vanadium homogeneous and supported ionic liquid (SIL) catalyst systems. The 13C and 1H NMR (carbon and proton nuclear magnetic resonance spectroscopy) together with differential scanning calorimetry (DSC) were applied to determine the composition of copolymers such as comonomer incorporation (CNB), monomer dispersity (MD), monomer reactivity ratio (re), sequence length of ethylene (le) and tetrad microblock distributions. The relation between the type of catalyst, reaction conditions and on the other hand, the copolymer microstructure, chain termination reaction analyzed by the type of unsaturation are discussed. In addition, the thermal properties of E-NB copolymers such as the melting and crystallization behavior, like also the heterogeneity of composition described by successive the self-nucleation and annealing (SSA) and the dispersity index (DI) were determined.


2018 ◽  
Vol 31 (5) ◽  
pp. 548-556 ◽  
Author(s):  
Yuane Wu ◽  
Chen Feng ◽  
Jiping Yang ◽  
Gong Chen

In this study, we report the preparation of thermosetting polyimides (PIs) based on carborane-containing tetramine and their characterizations. The novel tetramine 1,2-bis(4-(3,5-diaminobenzoic acid phenyl ester))carborane (CBNH) was synthesized and characterized firstly. Then, it was used in the preparation of two kinds of branched imide oligomers via the method of thermal imidization. The cure behavior of the obtained phenylethynyl-terminated oligomers was investigated by differential scanning calorimetry. The effect of carborane substituent on the thermal properties of PIs was studied by comparing with a similar structure without the carborane group. The thermal properties of PIs and carbon fiber/PI composites were investigated by thermal gravimetric analysis and dynamic mechanical analysis, respectively. Because of the introduction of high steric hindrance of carborane structure, the resulting thermosets and carbon fiber/PI composites had excellent thermal property with a high char yield at 800°C (>66.5%) and a high glass transition temperature (up to 500°C), respectively.


2020 ◽  
Vol 32 (7) ◽  
pp. 823-834
Author(s):  
Lei Zhang ◽  
Jiale Mao ◽  
Shuang Wang ◽  
Yiting Zheng

A series of main-chain benzoxazine oligomers with different methyl substitutions are successfully synthesized. Chemical structures are analyzed by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and gel permeation chromatography. Effects of methyl substitutions on chemical shifts of protons in oxazine ring and thermal properties, including glass transition temperature, thermal stability, and char yield, are discussed. The influences of methyl substitutions on different positions are demonstrated: (i) substitution on phenols induces obvious increase in curing temperature while substitution on amine does not show apparent impact; (ii) substitution at different positions results in T g variation, following the sequence of none-substitution > substitution at end-capping > substitution on diamines in main-chain > substitution on bisphenols in main-chain; and (iii) substitution at end-capping would cause apparent deterioration in thermal stability while substitution on diamines in main-chain would benefit thermal stability and char yield. Experimental results and related explanations are provided in detail.


2011 ◽  
Vol 284-286 ◽  
pp. 1863-1866 ◽  
Author(s):  
Wen Wen Shan ◽  
Guan Jun Chang ◽  
Fang Hua Zhu ◽  
Lin Zhang

The carbazoled poly(arylene imino)s (c-PAI) have been synthesized via palladium-catalyzed polycondensation of 3,6-diamino-N-(2-ethylhexyl)carbazole with different aromatic dibromides. The structure of c-PAI were characterized by means of FT-IR, 1H NMR spectroscopy and elemental analysis, the results show an agreement with the proposed structure. The thermal properties of c-PAI were detected by DSC and TG. The result show that the polymers possess high glass transition temperature (Tg>250°C ), good thermal stability with high decomposition temperatures (TD>410°C), In addition to the thermal properties, the optical properties were studied, including Uv-vis absorption, photoluminescence and time of flight (TOF).


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