Polymer Chemistry
·
2016
·Vol. 7
·期 48
·7427-7435
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IF 5.687
Nafeesa Mushtaq,Guofei Chen,Lala Rukh Sidra,Yang Liu,Xingzhong Fang
Two novel series of highly organosoluble and curable polyimides containing pendant nitrile groups PI (a–d) and phthalonitrile-terminated polyimides PN-PI (a–d) were prepared by solution polycondensation of isomeric bis(chlorophthalimides)s and 2,6-dichlorobenzonitrile with 4,4′-thiobisbenzenethiol. The inherent viscosities of these copolymers were in the range of 0.37–0.59 dL g−1 in N-methyl-2-pyrrolidone (NMP) at 30 °C. The phthalonitrile and pendant nitrile groups in isomeric poly(thioether-ether-imide)s were thermally crosslinked without a catalyst through thermal curing up to 280–360 °C, which led to the transformation from thermoplastic polymers to thermosetting polymers. All PIs before and after crosslinking were characterised by gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. PN-PI (a–d) and PI (a–d) were found to be highly soluble in some solvents, such as chloroform, dimethylacetamide, m-cresol, dimethlyformamide and N-methyl-2-pyrrolidone, while the crosslinked polymers were insoluble in all tested solvents. The crosslinking results of pendant nitrile and terminal phthalonitrile groups are also compared. Both series of PIs showed high thermal stability based on 5% weight loss temperature (T5%) in the range of 471–509 °C and increased up to 35 °C after thermal curing. Polyimides showed high glass transition temperatures (Tgs) ranging from 191–213 °C as determined by DSC, but no detectable Tg was observed after thermal heating, indicating the crosslinked structure of PIs. The mechanical properties also enhanced after the crosslinking of the copolymers. The tensile modulus and strength of the cured PI films were in the range of 3.3–4.7 GPa and 68–122 MPa, respectively, which were up to 62% and 35% higher than the uncured films.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 23
·5668
·
IF 4.2
Dengxun Ren,Zexu Fan,Jiaqu Zhang,Yi Xu,Xianzhong Tang,Mingzhen Xu
To study the properties of cyclotriphosphazene (CTP)-containing phthalonitriles, a branched phthalonitrile containing CTP (CTP–PN) with self-catalytic behavior was designed and synthesized. The structure of CTP–PN was characterized by FT–IR (Fourier transform infrared spectroscopy), MS (mass spectroscopy), 1 H–NMR (proton nuclear magnetic resonance spectroscopy), and 13 C–NMR (carbon nuclear magnetic resonance spectroscopy). Then, the curing reaction of CTP–PN was studied using DSC (differential scanning calorimetry) and DRA (dynamic rheological analysis). The results show that the curing reaction of CTP–PN is initiated at 200 °C. Additionally, the change in the viscosity of CTP–PN as a function of the temperature was investigated. After curing at different temperatures, the generated structures were characterized by FT–IR. The fracture morphology and thermomechanical properties of cured CTP–PN were scanned and studied using SEM (scanning electron microscopy) and TMA (thermomechanical analysis), respectively. The results demonstrate that CTP–PN exhibits a smooth fracture surface and possesses a relatively low CTE (coefficient of linear thermal expansion) of approximately 25 ppm/°C at 285 °C. A T d5% (temperature at which 5% weight loss occurs) of as high as 405 °C can be obtained for cured CTP–PN, and its char yield at 800 °C exceeds 70% in N 2 . FT–IR and XPS (X-ray photoelectron spectroscopy) were used to study the thermal decomposition of cured CTP–PN, indicating that it remains stable below 350 °C. With an increasing temperature, there is decomposition first of CTP and P–NH–Ph and C–O–C bonds (>350 °C) and then nitrogen-containing aromatic heterocycles (>500 °C), ultimately resulting in the formation of P-containing residual char.
研究领域:
材料科学
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化学
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DOI
PubMed
高影响因子
POLYMER INTERNATIONAL
·
2017
·Vol. 67
·期 3
·322-329
·
IF 2.07
Yu Qi,Zhihuan Weng,Jinyan Wang,Shouhai Zhang,Lishuai Zong,Cheng Liu,Xigao Jian
The development of bio-based thermosetting resins with good thermal stability can potentially afford sustainable polymers as replacements for petroleum-based polymers. We report a practical route to a novel catechin-based phthalonitrile resin precursor (CA-Ph), which contains free phenolic hydroxyl groups that result in ‘self-curing’ at elevated temperatures to afford a thermostable polymer. Comparison of the performance of this CA-Ph resin with that of a conventional petroleum-based bisphenol A phthalonitrile resin (BPA-Ph; containing 5 wt% of the curing agent 4,4′-diaminodiphenylsulfone) revealed that CA-Ph exhibits a lower melting point and curing temperature. Cured CA-Ph resin retains 95% of its weight at 520 °C under a nitrogen atmosphere, which compares favorably with results obtained for BPA-Ph resin that retains 95% of its weight at a lower temperature of 484 °C. Kinetic results indicated that the curing reactions of both CA-Ph and BPA-Ph systems follow an autocatalytic mechanism. These results suggest that catechin is a useful bio-based feedstock for the preparation of self-curing and thermally stable phthalonitrile resins for advanced technological applications. © 2017 Society of Chemical Industry
研究领域:
材料科学
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有机化学
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DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 17
·4411
·
IF 3.1
Cong Peng,Tao Luo,Zhanjun Wu,Shichao Li
The bisphenol A-type phthalonitrile (BAPH) was blended with the classic epoxy system E51/DDS to prepare the epoxy/phthalonitrile thermoset. The curing kinetics were investigated by differential scanning calorimetry (DSC) using the isoconversional principle, and the average activation energy (Eα) of the E51/DDS curing reaction was found to decrease from 87 kJ/mol to 68.6 kJ/mol. Combining the results of the rheological study, the promoting effect of phthalonitrile on the crosslink of epoxy/amine is confirmed. The curing reaction of the blended resin was characterized using FTIR, and the results showed that BAPH could react with DDS. The thermal behaviors of the thermosets were investigated via DMA and TGA. The glass transition temperature (Tg) is found to increase from 181 °C to 195 °C. The char yield increases from 16% to 59.6% at 800 °C in a N2atmosphere, which is higher than the calculated value based on the proportional principle. The AFM phase images show that there is no phase separation in the cured thermoset. The results imply that the cured epoxy/amine/phthalonitrile blend is probably a kind of copolymer. The real-time TG-MS indicated that the pyrolysis of the thermoset can be divided into two relatively independent stages, which can be assigned to the cleavage of the E51/DDS network, and the phthalocyanine/triazine/isoindoline, respectively.
研究领域:
材料科学
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化学工程
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DOI
PubMed
高影响因子
POLYMER
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2024
·
IF 4.1
Zichun Ding,Siying Wang,Runze Liu,Yuhang Wang,Jianing Guo,Xuedong Wu,Jiaming Wang,Xigao Jian,Lishuai Zong,Jinyan Wang
Phthalonitrile (PN) resin is renowned for its absence of small molecule release during curing, high processing stability, and exceptional thermal stability, positioning it favorably in the realm of high-temperature resin applications. However, its narrow processing window and high melting point present challenges to its development and practical use. To address these limitations, this work synthesized PN prepolymers 4,4′-bis (sulfonylbiphenyl) thiophtalonitrile (BSPS) and 4,4′-bis(carbonylbiphenyl) thiophtalonitrile (BSPC) by introducing thioether bonds as a substitute for ether bonds, aiming to expand the prepolymers' processing window. Meanwhile, building upon the oxidation process of thioether to sulfone observed in pharmaceutical production, the potential for in-situ oxidation of thioether bonds during the curing of phthalonitrile prepolymers was investigated. A comprehensive analysis of the curing behavior, viscosity changes, and thermal stability was conducted using differential scanning calorimetry (DSC), rheological analysis, and thermogravimetric analysis (TGA). The DSC and rheological test results reveal that the experimental group prepolymers BSPS and BSPC exhibit lower melting points (BSPS 179 °C; BSPC 180 °C) and broader processing windows (BSPS 52 °C; BSPC 79 °C) than blank. Additionally, the thermal performance of resins show improvement over the blank, with BSPS achieving a decomposition temperature of up to 530 °C ( T d5% ). XPS analysis of the curing process confirmed that the enhanced thermal stability is attributable to the partial oxidation of thioether bonds into stable sulfone groups. This innovative structural approach allows for satisfactory processing performance in the initial stage, followed by a spontaneous transformation into a more robust and thermo-resistant structure post-shaping. This finding carries significant implications for the development of a balanced phthalonitrile system that harmonizes processing ease with superior thermal endurance.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2025
·
IF 8.9
Yabin Zhang,Jiaming Wang,Xuedong Wu,Linyan Zhu,Wenguang Zhang,Lishuai Zong,Jinyan Wang,Xigao Jian
The robust operation of electromagnetic waves in communication systems with extreme temperatures relies on high-temperature resistant wave-transparent composites, with organic resin matrix being a pivotal constituent. Enhancing the heat resistance of resins while maintaining excellent processability poses a significant challenge. Herein, a novel “rigid-in-flexible” self-curing silicon-based silicon-based phthalonitrile monomer containing phenylacetylene backbone (Si-ALK-PN) was designed. The silazane component disrupts the crystallinity in Si-ALK-PN, resulting in a characteristic of low viscosity (0.3 Pa·s) and extended processing window (>3h). After curing at 450 °C, the resin, namely Si-ALK-PN-450 °C, demonstrated exceptional thermal stability ( T 5% = 631 °C) and thermo-oxidative stability ( T 5% = 560 °C). Their quartz fiber-infused composites (Si-ALK-PNs/QF) were manufactured through a straightforward melt processing approach. Upon post-curing at 450 °C, Si-ALK-PN-450 °C/QF exhibited elevated glass transition temperature, flexural strength, and consistent dielectric properties across a wide temperature ranging from 25 °C to 600 °C. Especially, it exhibited excellent flame retardancy as well, stemming from release of eco-friendlyeco-friendly inert gases (NH 3 ) and the high thermal stability of N-enriched all-aromatic PN resin. The design concept of “rigid-in-flexible”, along with the multi-functional group co-curing strategy, offers a promising solution for addressing the trade-off between processing and heat resistance in resins, extending beyond PN resins.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
POLYMER
·
2021
·
IF 4.43
Chong Gao,Hongbo Gu,Ai Du,Heng Zhou,Duo Pan,Nithesh Naik,Zhanhu Guo
Herein, we have reported that the polyaniline (PANI), as a polymeric catalyst, exhibits an outstanding efficiency for the curing of phthalonitrile resin as verified by differential scanning calorimetry (DSC) with a high enthalpy, in which the triazine structure is the dominating curing products as confirmed in the Fourier transform infrared (FTIR) spectra. Thermogravimetric analysis (TGA) and nanoindentation tests have been carried out to investigate the thermal and mechanical properties of the cured PANI/phthalonitrile resin. The results demonstrate that the PANI/phthalonitrile resin not only manifests a high char yield up to 24.7% at temperature of 850 °C in the air atmosphere, but also possesses an improved hardness that is 81.8% higher than that of regular small molecule of amine catalyst/phthalonitrile resin.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yabin Zhang,Wenguang Zhang,Houxiang Yin,Yanlin Wang,Bingbing Wang,Lishuai Zong,Jinyan Wang,Xigao Jian
The robust human–machine interaction systems of the aerospace industry necessitate the development of thermal resistant wave-transparent composites, with a pivotal focus on organic resin matrix. However, enhancing the heat resistance of such materials while preserving other critical attributes has been a formidable challenge. In this study, a novel designed strategy of a dual-curing functional phosphorus-based phthalonitrile monomer (P-ALK-PN) has been proposed. The optimized curing temperatures for intra- or intermolecular Diels-Alder reactions of alkynyl groups and polyaddition reaction of cyano groups resulted in a homogeneous and highly crosslinked N-enriched phthalonitrile system. After curing at 450 °C, the resin, namely P-ALK-PN-450 °C, demonstrated exceptional thermal stability ( T 5% = 644 °C), thermo-oxidative stability ( T 5% = 554 °C), and char yield at 800 °C (90.7 % in N 2 and 67.5 % in air). Their quartz fiber reinforced composites (P-ALK-PN/QFs) were subsequently fabricated by the hot-pressing process. Upon post-curing at 420 °C, P-ALK-PN-420 °C/QF displayed elevated glass transition temperature (550 °C), flexural strength (319 MPa), and relatively low dielectric properties with a dielectric constant (D k ) of approximately 4.2 and a dissipation factor (D f ) less than 0.02 across a wide temperature ranging from 25 °C to 600 °C. Especially, it exhibited excellent flame retardancy (only a 6.7 % weight loss at ambient temperatures exceeding 1300 °C for 200 s) as well, stemming from release of eco-friendly inert gases (NH 3 ) and formation of a graphitized protective layer during pyrolysis. These promising results highlight the potential applications of P-ALK-PN resins in aerospace and high-performance engineering fields.
研究领域:
材料科学
·
航空航天工程
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DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2024
·
IF 1.8
Dengke Li,Han Zhao,Zhiyi Jia,Dianqiu Jia,Jianxin Rong,Huaijie Yan,Xiaoyan Yu,Qingxin Zhang
Composites based on high-performance resin matrix have excellent high temperature resistance, chemical stability, and excellent processability, and exhibit a wide range of applications in many fields. At present, there are no reports on the application of calcium sulfate whiskers (CSW) in phthalonitrile resins. In this study, KH560 was used to modify CSW, through FT-IR, TGA, XRD and XPS methods, KH560 was successfully grafted onto CSW, and the modified CSW was filled with phthalonitrile resin containing fluorine elements. SEM shows that the modified CSW is uniformly dispersed in the resin. The storage modulus of composites increased from 2.6 GPa to 3.8 GPa. Under air and nitrogen atmospheres, the T5% of the composites increased by about 10°C. When the addition amount of CSW is 10%, the friction coefficient of the material is reduced from 0.68 to 0.58, the depth of wear marks decreased from 49.1 μm to 27.9 μm, the wear rate of AFPN-10 (the addition amount of CSW is 10%) decreases from 3.59 × 10−4 mm3/(N·m) to 2.70 × 10−4 mm3/(N·m), the wear resistance performance was significantly improved. With the increase of CSW in composites, the hardness, reduced modulus and elastic recovery rate are also gradually increasing, the highest reduced modulus and hardness are 2434 MPa and 597 MPa respectively. The addition of CSW can improve the mechanical properties and thermal properties of the phthalonitrile resin, as well as enhance its anti-friction ability. Phthalonitrile resin-based composites have potential application values in the fields of aerospace, electronic instruments and lightweight components.
研究领域:
材料科学
·
航空航天
·
化学工程
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DOI
高影响因子
POLYMER
·
2019
·
IF 3.771
Yue Han,Donghao Tang,Guangxing Wang,Youlan Zhang,Ying Guo,Heng Zhou,Wenfeng Qiu,Tong Zhao
Soluble hyperbranched poly(arylene ether nitrile)s end-capped by either hydroxyl (HBPAEN-OHs) or phthalonitrile groups (HBPAEN-PNs) were synthesized via nucleophilic substitution reactions , where activated carbon supported calcium oxide was used as the catalyst to avoid crosslinking at high conversion. In order to evaluate their potential application in phthalonitrile resins, these hyperbranched polymers were blended with 1,3-bis(3,4-dicyanophenoxy)benzene and 4-(4-aminophenoxy)phthalonitrile, then cured into polymers. Curing mechanisms of different prepolymers were proposed and compared, and processability, thermal and mechanical properties were characterized. The introduction of HBPAEN-OHs was found to postpone the curing, while thermal and mechanical properties were compromised. On the contrary, the usage of HBPAEN-PNs was beneficial to both processability and thermal properties. More importantly, the impact strength for polymers containing HBPAEN-PN could be as high as 12.92 kJ m −2 , indicating such resin could be potentially applied as high temperature structural composite matrices. In addition, the toughening mechanism was proposed and discussed.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2020
·
IF 4.032
Xian He,Shenjun Liao,Menghao Chen,Renke Li,Yao Liu,Bo Liang,Jianghuai Hu,Ke Zeng,Gang Yang
Tyrosine derived cyclic peptide (TCP) was employed to promote the curing reaction of a phthalonitrile monomer 1,3-bis(3,4-dicyanophenoxy) (3BOCN). Differential scanning calorimetry (DSC) and rheological analysis were used to study the curing behaviors of the TCP/3BOCN blend and confirmed a relatively high curing efficiency. Fourier transform infrared spectrometer (FT-IR) and two-dimensional infrared vibrational echo spectroscopy suggested the cyclic peptide reactive site was responsible for the unique curing behavior. Isoindolin, phthalocyanine and triazine were confirmed as curing products. Thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) were used to measure the thermal and thermomechanical properties of the cured resin. The results firstly revealed the excellent thermal stability and high glass transition temperature (T g ) of this resin even under a moderate post-curing condition.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2021
·
IF 2.694
Kui Wu,Youliang Guan,Zujin Yang,Hongbing Ji
The solid–liquid equilibrium of isophthalonitrile (IPN) in 16 solvents (methanol, ethanol, n-propanol, isopropanol, acetone, ethyl acetate, acetonitrile, chloroform, cyclohexanone, cyclopentanone, methyl acetate, ethyl formate, 2-pentanone, tetrahydrofuran, toluene, and diethyl ether) was measured by using a static equilibrium method at temperatures T = 273.15–324.75 K under atmospheric pressure. The results demonstrated that the solubility of IPN in these 16 monosolvents increased with increasing temperature. The largest solubility values of IPN were found in cyclopentanone, and the lowest were in isopropanol. The values of solubility in ketones were much larger than those in esters and alcohols. In alcohols, the solubility ranked as methanol > ethanol > n-propanol > isopropanol, and the sequence was identical to that of the solvent polarities. The polarity of the solvent is an important factor influencing the solubility profiles of IPN in alcohols, despite that the conclusion is not supported by other kinds of solvents studied. Moreover, the Apelblat equation, λh equation, Wilson model, and nonrandom two-liquid model were used to correlate the experimental values. The calculated values of four models all provided good fitting results with the experimental data, and the values of root-mean-square deviation and relative average deviation (RAD) were no more than 6.84 × 10–4 and 6.84 × 10–3, respectively. Furthermore, the thermodynamic properties of the mixing process for IPN in selected solvents were calculated, that is, mixing Gibbs energy (ΔmixG), molar enthalpy (ΔmixH), and molar entropy (ΔmixS). The results indicated that the mixing process of IPN was a spontaneous and entropy-driven process. The solid–liquid equilibrium data and solution thermodynamics would be helpful for the synthesis and purification of IPN in the industry.
研究领域:
化学工程
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物理化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）