聚芳醚腈砜的合成与介电性能

以2,6-二氯苯甲腈(DCBN)和4,4-二羟基二苯砜(DHDPS)为原料,通过常压溶液缩聚合成了一种耐高温的无定形聚芳醚腈砜(PENS)。用FT-IR,DSC,TG等手段对PENS聚合物的结构和热性能进行了研究,同时表征了PENS薄膜的介电性能。结果表明:PENS具有很高的玻璃化转变温度(215.4℃),5%热失重温度为453℃。PENS具有很好的介电性能,其介电常数为3.6~4.1 F/m,在玻璃化转变温度前具有很好的介电稳定性。     

聚芳醚腈/富勒烯复合薄膜制备与性能研究

以聚芳醚腈树脂为基体、富勒烯为纳米功能填料制备了聚芳醚腈介电功能复合薄膜。首先通过共溶剂控制蒸发法制备了聚芳醚腈/富勒烯低介电薄膜。着重分析了共溶剂控制蒸发分散方法对富勒烯分散效果以及薄膜性能的影响。研究发现:利用聚合物大分子链与填料粒子逐渐相互缠结的原理,共溶剂控制蒸发法对于制备可溶解性纳米填料的复合材料可以达到极佳的分散效果,获得的复合薄膜不仅具有低于2.0的介电常数,而且其热性能和力学性能都得以提高。     

氰基化钛酸钡对聚芳醚腈介电薄膜结构与性能的影响

首先通过化学接枝法在钛酸钡纳米粒子(BT)表面依次接枝了异佛尔酮二异氰酸酯(IPDI)和3-氨基苯氧基邻苯二甲腈(3-APN),得到氰基功能化的钛酸钡纳米粒子(BT-CN);接下来,将其与聚芳醚腈(PEN)复合,制备了聚芳醚腈/氰基化钛酸钡复合介电薄膜。通过傅里叶红外光谱(FTIR)、X射线光电子能谱(XPS)、热重分析仪(TG)证实了BT成功进行了表面功能化。此外,BT-CN的加入可以有效增强PEN复合薄膜的热学、力学和介电性能;相较于纯PEN,复合薄膜的玻璃化转变温度增加了12℃,拉伸强度提高了9.6%,1 kHz时介电常数提高了227.8%。综上所述,氰基功能化有利于改善有机-无机界面相容性,从而进一步提高复合薄膜的综合性能。     

玻纤/石墨/聚芳醚腈复合材料的制备与性能

以聚芳醚腈(PEN)为基体,采用双螺杆挤出机熔融共混制备了玻纤、石墨复合材料,重点研究了两种不同形貌的增强填料对PEN树脂的协同增强作用。测试了不同样品的拉伸、弯曲和冲击等力学性能,利用扫描电镜对拉伸断面进行形貌分析,并对样品进行了TGA测试和流变性能测试。结果表明,大量玻纤以棒状存在于PEN树脂当中,构成骨架结构,使得PEN树脂力学性能大幅度提高,石墨以片层形状存在于PEN树脂与玻纤之间,进一步增强了PEN树脂基体的连接作用,从而使得复合材料力学性能进一步提高;石墨在提高PEN树脂强度的同时能够提高PEN树脂的热稳定性;在相同频率下,PEN基复合材料的储能模量和耗能模量均随玻纤和石墨填料含量增加而提高,低含量的石墨填入对体系的模量和黏度影响较小。     

聚酰亚胺/二氧化硅杂化膜的制备与介电性能的研究

采用溶胶-凝胶法制备了BTDA-ODA聚酰亚胺/SiO2杂化膜,利用红外分光光度计（FTIR）、热重分析仪（TGA）和透射电镜（TEM）研究了杂化膜的微观结构和热性能,并对杂化膜的介电常数（e）和介电损耗（tand）随SiO2粒子含量和电场频率的变化进行了分析和讨论。结果表明：杂化膜的介电常数和介电损耗随SiO2粒子含量的增加而增大,随电场频率的升高而逐渐降低,用考虑到粒子的形状因素和两相间相互作用的EMT模型可以预测聚酰亚胺/SiO2杂化膜的介电常数。     

聚芳醚腈合金的制备及性能研究

将2类聚芳醚腈（PEN）共聚物PEN（HQ／RS）和PEN（HQ／PP）,按不同质量比通过熔融共混制备PEN合金材料,测试其相容性、力学性能和热性能,发现聚合物合金在PEN（HQ／RS）质量分数分别为20％和80％时相容性良好,PEN（HQ／RS）的加入改善了PEN（HQ／PP）的加工性能,实验中不同质量比的合金均具有优良的力学性能和热性能。     

聚芳醚腈/聚苯硫醚合金的制备及性能研究

将聚芳醚腈(PEN)与商用聚苯硫醚(PPS)按不同比例通过熔融共混制备系列合金材料。研究结果显示PEN与PPS有较好的相容性,共混合金的力学性能处于纯聚合物力学性能区间。通过流变研究表明PPS与PEN的共混物在剪切条件下,黏度较纯PEN树脂有明显降低,有效改善了后者的加工性能,合金的耐热性能较PPS树脂有大幅提高。     

聚芳醚腈树脂及其复合材料的研究

以对苯二酚(HQ)、间苯二酚(RS)和2,6-二氯苯腈(DCBN)为原料,N-甲基吡咯烷酮为溶剂,通过非质子催化剂与脱水剂的协同作用下的一步加料工艺技术在工业装置上成功合成了聚芳醚腈共聚物PEN(HQ-RS),并利用双螺杆挤出机制备了PEN(HQ-RS)/玻纤复合材料和PEN(HQ-RS)/石墨复合材料。性能表征表明,聚芳醚腈树脂及其复合材料具有优异的力学性能、电性能、耐高温特性和自阻燃性。     

聚芳醚腈砜碳布层压板和玻璃布层压板的研制

本文以２,６－二氟苯甲腈和４,４－二羟基二苯砜为主要原料合成了聚芳醚腈砜利用ＩＲ、＾１３Ｃ－ＮＭＲ和热分析等手段对其结构和热性能进行了表征。以取长醚腈砜为基体树脂采用特殊的溶液浸胶工艺,一次邓要制我含量达４５％的预浸料。制得的碳布层压板和玻璃布层压板皆具有优异的力学性能和热性能,可在１８０℃使用。     

热处理对聚芳醚腈/改性石墨复合材料性能的影响

采用邻苯二甲腈预聚物物理包覆的方法改性纳米石墨薄片,熔融挤出制备了聚芳醚腈(PEN)/纳米石墨薄片复合材料。研究了纳米石墨对PEN的增强作用,并重点研究了热处理对复合材料力学性能和热性能的影响。结果表明,纳米石墨薄片对PEN有很好的增强作用,其质量分数为10%时,复合材料的拉伸强度、弯曲强度分别提高了10%和25%。从SEM分析可以看出,邻苯二甲腈预聚物(PNP)改性的纳米石墨薄片均匀地分散在PEN基体中,并且增强了与PEN的界面作用力。PEN/纳米石墨薄片复合材料在290℃热处理2h,其弯曲强度提高40%,玻璃化转变温度提高了13℃,初始分解温度提高了近15℃。从红外图谱可以反映出,复合材料热处理后力学性能和热性能的提高是因为PNP和PEN之间发生了一定程度的交联反应,这种交联反应使PEN与纳米石墨薄片的界面作用力大大增强。     

Crystallinity of poly(arylene ether nitrile) copolymers containing hydroquinone and bisphenol A segments

The hydroquinone (HQ) and bisphenol A (BPA) type poly(arylene ether nitrile) (PEN) (HQ/BPA‐PEN) were synthesized through nucleophilic aromatic substitution polymerization from HQ, BPA, and 2,6‐dichlorobenzonitrile (DCBN). The prepared copolymers were characterized by intrinsic viscosity, Fourier transform infrared (FTIR), and dynamic rheological analysis. The properties of resultant copolymers were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and mechanical testing. The results showed that the PEN copolymers exhibited crystallization performance with excellent thermal and mechanical properties. HQ/BPA‐PEN10 was made into films by solution‐casting process and then were treated at different temperatures (200, 260, 280, 300, 310, and 320 °C) for different times (1, 2, 3, 4, and 5 h) to investigate the crystallinity. Results showed that when isothermal treatment temperature is 310 °C and isothermal treating time is 4 h, HQ/BPA‐PEN10 showed best properties. At this condition, the melting enthalpy, crystallinity, tensile strength, and elongation at break of the sample is 17.7 J/g, 14.11%, 132.9 MPa, and 6.1%, respectively. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46412.     

Effect of nitrile functionalized graphene on the properties of poly(arylene ether nitrile) nanocomposites

In this study, novel nitrile functionalized graphene (GN‐nitrile)/poly(arylene ether nitrile) (PEN) nanocomposites were prepared by an easy solution‐casting method and investigated for the effect of surface modification on the dielectric, mechanical and thermal properties. Graphene (GN) was first functionalized by introduction of nitrile groups onto the GN plane, which was confirmed by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, thermogravimetric analysis and dispersibility research. Compared with pure GN, the grafted nitrile groups on the GN‐nitrile can interact with nitrile groups in PEN and lead to flat but better dispersion and stronger adhesion in/to the PEN matrix. Consequently, GN‐nitrile had a more significant enhancement effect on the properties of PEN. The dielectric constant of the PEN/GN‐nitrile nanocomposite with 5 wt% GN‐nitrile reaches 11.5 at 100 Hz, which is much larger than that of the pure PEN matrix (3.1). Meanwhile, dielectric loss is quite small and stable and the dielectric properties showed little frequency dependence. For 5 wt% GN‐nitrile reinforced PEN composites, increases of 17.6% in tensile strength, 26.4% in tensile modulus and 21 °C in T_d5% were obtained. All PEN/GN‐nitrile nanocomposite films can stand high temperature, up to 480 °C. Hence, novel dielectric PEN/GN‐nitrile nanocomposite films with excellent mechanical and thermal properties can be used as dielectric materials under some critical circumstances such as high wear and temperature. Copyright © 2012 Society of Chemical Industry     

Synthesis and properties of crosslinked poly(arylene ether nitriles) containing pendant phthalonitrile

In this study, poly(arylene ether nitriles) containing pendant carboxyl groups (PEN‐COOH) was first synthesized via nucleophilic aromatic substitution reaction from phenolphthalein, hydroquinone and 2,6‐dicholorobenzonitrile. Then, poly(arylene ether nitriles) with pendant phthalonitrile groups (PEN‐CN) was obtained via the Yamazaki–Higashi phosphorylation route from 4‐(4‐aminophenoxy)phthalonitrile (APN) with PEN‐COOH in the presence of CaCl₂, thus the phthalonitrile as pendant groups in PEN‐CN were easily crosslinked by further thermal treatment. The effect of crosslinking density on the thermal stabilities, dielectric properties and water absorption of the PEN‐CNs was investigated. These results showed that the T_g of PEN‐CN was improved from 182 to 213°C, dielectric constant (ε) was increased from 3.1 to 3.9, and dielectric loss (tan δ) was decreased from 0.090 to 0.013 at 1 kHz. The water absorption of PEN‐CNs after thermal crosslinking was <1.01 wt %, which showed excellent water resisting property. Therefore, this kind of poly(arylene ether nitriles) containing pendant phthalonitrile could be a good candidate as matrix resins for high‐performance polymeric materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of phenolphthalein/bisphenol A-based poly(arylene ether nitrile) copolymers: Preparation and properties of films

Poly(arylene ether nitrile) (PEN) is a class of high-performance engineering plastics of poly(arylene ether) with cyano groups as side groups, which can get improved thermal, mechanical, and electrical properties through simple molecular structure design. In this work, a series of PEN (BPA/PP based PEN) copolymers were synthesized with varying amounts of phenolphthalein and bisphenol A. The influence of the copolymer molecular structure variations on the thermal, mechanical, and dielectric properties of PEN copolymer films was investigated. The results demonstrated that the BPA/PP based PEN copolymer films have great mechanical properties and low dielectric constant, as well as enhanced thermal properties. The highest 5% weight loss temperature of 494.9°C was obtained by PEN-B7P3, while the highest glass transition temperature of 238.6°C was obtained by PEN-B3P7. Porous BPA/PP based PEN films prepared by non-solvent induced phase separation (NIPS) exhibited satisfactory mechanical properties and the highest tensile strength of 9.4 MPa was achieved. Moreover, the introduction of the phenolphthalein structure into the PEN molecular chain can improve the heat resistance of the PEN copolymers without deteriorating the dielectric properties, which gives the copolymers great potential as candidates for applications in flexible electronics and wireless communication.     

Effect of curing behaviors on the properties of poly(arylene ether nitrile) end-capped with phthalonitrile

Poly(arylene ether nitrile) (PEN) end-capped with phthalonitrile (PEN-n) was synthesized by incorporating phthalonitrile into the terminals of PEN. The as-prepared flexible PEN-n (after elevated temperature treatment) was characterized by infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, and rheological measurements. In addition, the effects of curing behaviors on properties of PEN-n films were studied by thermal, dielectric and mechanical measurements. Differential scanning calorimetry analysis showed that glass transition temperature of PEN-n was improved from 176 to 232°C as the curing temperature and time increased. Thermal gravimetric analysis revealed that initial decomposition temperature of PEN-n cured at 320°C for 2 h was 570°C. Mechanical properties showed that tensile strength of PEN-n uncured and cured at 320°C for 3 h was 85 and 97 MPa, respectively. The dielectric properties showed that the dielectric constant of PEN-n film decreased from 4.0 to 3.1 as the curing time increased and dielectric loss of PEN-n was 0.01 at 100 kHz. This kind of PEN-n film may be used as a good candidate for high-performance polymeric materials. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation and dielectric properties of sulfonated poly(aryl ether ketone)/acidified graphite nanosheet composites

Percolative dielectric composites of sulfonated poly(aryl ether ketone) (SPAEK) and acidified graphite nanosheets (AGSs) were fabricated by a solution method. The dielectric constant of the as‐prepared composite with 4.01 vol % AGSs was found to be 330 at 1000 Hz; this was a significant increase compared to that of pure SPAEK. Through the calculation, a low percolation threshold of the AGS/SPAEK composite was confirmed at 3.18 vol % (0.0318 volume fraction) AGSs; this was attributed to the large surface area and high conductivity of the AGSs. Additionally, our percolative dielectric composites also exhibited good mechanical performances and good thermostability, with a tensile strength of 71.7 MPa, a tensile modulus of 1.91 GPa, a breaking elongation of 16.4%, and a mass loss temperature at 5% of 336°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40028.     

Effect of nonsolvent on the structures and properties of poly(arylene ether nitrile) films prepared by the phase inversion method

In this study, a series of nonsolvents including ethyl acetate (EAC), acetic acid (HAC), n-butyl alcohol (NBA), iso-propyl alcohol (IPA) and ethanol (EA) were selected during the phase inversion process of poly(arylene ether nitrile) (PEN) films. The mechanism of film formation was tightly related with the interactions among polymer, solvent and nonsolvent. In the case of EAC, the aggregated sphere in P-EAC confirmed the in situ aggregate mechanism of polymer chains during the phase inversion process. As the nonsolvent-polymer interaction increases from HAC, NBA, IPA to EA, the phase inversion mechanism was gradually changed from the delayed to transient, as verified by the morphology transformation from spongy-like to finger-like. Dielectric, mechanical properties of these PEN films are tightly related with the morphological features, while their thermal properties are similar. Among them, P-EAC show the optimal properties for potential application in the low-k films, with a dielectric constant, T_d5%, tensile strength of 1.99, 515.84°C, and 36.08 MPa, respectively. This work can provide references for tailoring the structures and properties of PEN films through rational selection of nonsolvent via the phase inversion method.     

Polyarylene ether nitrile/divinyl siloxane-bisbenzocyclobutene composite films: Curing reaction and thermal/mechanical/dielectric properties

Polymer dielectrics, are commonly used as insulating materials for electronic products. Light weight, good mechanical properties and high thermal conductivity are important properties. However, electrical and thermal parameters are interrelated, and it is challenging to have a dielectric polymer that is also resistant to high temperatures and high thermal conductivity. Hence, high-performance composite films were prepared by the method of post-solid phase chemical reaction using polyarylene ether nitrile (PEN) and divinyl siloxane-bisbenzocyclobutene (BCB) as raw materials. First, parameters of the curing reaction were determined by rheological and activation energy calculations. Then, through adjusting the content of BCB resin and treatment temperature, the performance of PEN/BCB composites could be tuned. Thermal properties have been studied by differential scanning calorimetry, dynamic mechanical analysis, thermal gravimetric analysis, and hot-disk method. Here, the PEN/BCB composite electric insulating materials with outstanding thermal performance (T_g: 208–400°C, T_5%: 469–544°C, thermal conductivity: 1.270–2.215 W/m K). Besides, its mechanical and dielectric properties were investigated in detail. It is noteworthy that the tensile strength of composite film can exceed a maximum of 130 MPa, which is 23.19% higher compared to the untreated one. Also, PEN/BCB composites own low dielectric constant (2.27–4.08 at 1 KHz), and the relationship between frequency or a wide temperature range and dielectric constant/loss is stable. Thus, it has a greater potential for applications in electronics in high-temperature environments.     

Comparative study on the tribological properties of poly(arylene ether nitrile)/polytetrafluoroethylene composites: The influence of filler size and testing conditions

In this work, the influence of polytetrafluoroethylene (PTFE) filler size and testing conditions (i.e., air, water, and lubricating oil) on the tribological properties of poly(arylene ether nitrile) (PEN) was systematically investigated. The results showed that the addition of PTFE was beneficial to improve the tribological properties of PEN-based composites which was related to the easier formation of transfer film on the surface of friction pair. Samples which were tested in water demonstrated a relatively higher friction coefficient (μ) and wear loss when compared with those tested in dry air and lubricating oil scenarios, which was attributed to the fact that friction induced heat and wear debris could be timely removed by water. In addition, the infiltration of water further reduced the interaction between PTFE filler and PEN, which aggravated the wear loss of sample blocks. When tested in lubricating oil, pure PEN showed the lowest wear loss when compared with that of PEN/PTFE composites. At a given content (20 wt%) of PTFE fillers, PEN/PTFE_1.5μm exhibited the lowest μ in lubricating oil whereas PEN/PTFE_5μm demonstrated the lowest specific wear loss in air condition (1.18 × 10⁻⁶ mm³/N·m). This work provided some useful information for the design and application of PTFE-containing polymer composites that can be targeted in different lubrication scenarios in industrial fields.