氰酸酯树脂体系介电性能研究新进展

综述了近年来国内外氰酸酯树脂体系介电性能研究的新进展,主要包括催化剂体系、两相体系及新型氰酸酯树脂单体等对氰酸酯树脂介电性能的影响,并对提升氰酸酯树脂介电性能值得关注的发展方向作了展望.     

纳米SiO2对聚苯醚树脂/氰酸酯复合材料性能的影响

以聚苯醚树脂(PPO)改性BCE(双酚A型氰酸酯)作为复合材料的基体树脂,以硅烷偶联剂(KH-560)处理过的纳米二氧化硅(nano-SiO2)作为改性剂,制备出nano-SiO2/PPO/BCE复合材料.结果表明:适量的nano-SiO2既可同时提高PPO/BCE体系的韧性和强度,又可改善其介电性能和吸湿性能;当w(...     

氰酸酯树脂/纳米六方氮化硼复合材料研究

将纳米六方氮化硼(HBN)粒子加入氰酸酯树脂(CE)基体中,以二月桂酸二丁基锡和环氧树脂EP-54为引发剂,制得CE/HBN系列浇铸体复合材料.测试了浇铸体型材的力学性能、玻璃化温度、介电性能和耐酸碱腐蚀性能,并通过浇铸体型材微观形貌变化分析了复合材料型材力学性能得以提高的原因.结果表明,当纳米HBN粒子的质量分数为3...     

SiO2粒径对环氧树脂复合材料介电性能的影响

将不同粒径的SiO2微球与环氧树脂复合,制备用于直流特高压关键设备的高性能环氧绝缘复合材料,分析了其体积电阻率、介电常数与损耗,考察了SiO2微球对复合材料主要电气性能的影响;通过扫描电镜、动态热分析SiO2微球与环氧树脂的界面作用. 结果表明,不同粒径的SiO2微球均对环氧树脂复合材料性能有改善作用,添加100 nm SiO2的复合材料提升效果最显著,体积电阻率从1.87′1017 W×cm提至3.24′1017 W×cm,介电常数实部从10.99降至4.92,玻璃化转变温度从104.9℃升至106.4℃,这是因为100 nm SiO2微球表面吸附水分少、与树脂作用力强.     

弹性纳米粒子/纳米TiO2/聚丙烯复合材料的研究

采用专利技术制备了弹性纳米粒子(ENP)／纳米二氧化钛(TiO2)复合材料，并使用这种复合材料改性聚丙烯(PP)，制备了具有较高韧性和较好灭菌性能的PP纳米复合材料。当丁苯ENP的用量为2％，平均粒径为50nm的金红石型TiO2用量为1％时，所研制的PP纳米复合材料的冲击强度可提高30％以上，灭菌率可达60％。     

氰酸酯树脂/纳米γ-Al2O3复合材料的制备及性能

将纳米γ-Al_2O_3粒子加入氰酸酯树脂(CE)及环氧树脂(E-54)中,由二月桂酸二丁基锡(DBTDL)引发体系发生自由基聚合反应,制得CE/γ-Al_2O_3系列复合材料。采用示差扫描量热分析、电镜分析及力学、导热性、介电性和耐酸碱腐蚀性测试研究了纳米γ-Al_2O_3粒子用量对复合材料性能的影响。结果表明,无机纳米γ-Al_2O_3粒子的引入有利于CE基体树脂的聚合,其质量分数为10.0%时,复合材料DSC峰顶温度由280.9℃降至218.9℃,导热系数增大8.19倍,电绝缘性良好。其质量分数为6.0%时,复合材料弯曲强度、冲击强度分别达到165.36MPa,14.18 k J/m~2,较纯CE树脂提高了95.34%和62.24%,强酸腐蚀率为0.078%,较纯CE树脂下降42.8%。其质量分数为7.0%时,复合材料强碱腐蚀率为0.162%,较纯CE树脂下降64.8%。综合考虑,无机纳米γ-Al_2O_3粒子的最佳添加质量分数为6.0%。     

纳米TiO2/PP复合材料的研究

研究了纳米TiO2／PP复合材料的力学性能和耐老化性能，实验结果表明，添加1％－2％的纳米TiO2可以明显改善PP材料的抗冲击性能；纳米质量分数在1％－4％范围内对复合材料的拉伸强度几乎没有影响；而添加少量的纳米TiO2可以大大提高PP材料的耐紫外光老化性能，说明纳米TiO2对紫外光有极强的吸收能力。TiO2/PP复合材料具有良好的耐候性，可以提高其户外制品的使用寿命。     

钼酚醛树脂/TiO2纳米复合材料的研究

采用原位聚合法，用经表面处理的纳米TiO2对钼酚醛树脂进行填充改性，制备了钼酚醛树脂／TiO2纳米复合材料，研究了纳米TiO2用量对复合材料耐热性和力学性能的影响。结果表明，TiO2用量为1％时，纳米复合材料的玻璃化湿度和冲击强度达到最大值；TiO2用量为3％时，纳米复合材料的拉伸弹性模量和拉伸强度达到最大值。     

改性氰酸酯树脂基复合材料的研究

本文研究了双酚Ａ型氰酸酯树脂,４,４‘－双马来酰亚胺基二苯甲烷和Ｅ－５１环氧 脂三元共聚体系的物理性能,反应性以及玻璃布增强复合材料的力学性能和介电性能。     

纳米二氧化硅/超支化聚硅氧烷/氰酸酯树脂复合材料的性能研究

采用硅烷偶联剂表面处理过的纳米二氧化硅(nano-SiO2)作为填料改性超支化聚硅氧烷/氰酸酯(HBPSi/CE)树脂体系。结果表明:适量的nano-SiO2既可同时提高HBPSi/CE树脂的韧性和强度,又可改善其耐水性能;当nano-SiO2质量分数为3.0%时,nano-SiO2/HBPSi/CE体系的冲击强度(14.1 kJ/m2)和弯曲强度(118.4 MPa)分别比HBPSi/CE树脂提高了26%和12%,其吸水率低于HBPSi/CE树脂,介电常数略高于HBPSi/CE树脂,介电损耗角正切与HBPSi/CE树脂相当。     

酚类改性氰酸酯树脂体系介电性研究

采用DSC和红外等方法研究了酚对氰酸酯树脂固化反应的影响,以及不同酚含量的氰酸酯树脂体系及其复合材料在常温、高温、宽频(7~18 GHz)等条件下介电常数及介电损耗。结果表明,酚的加入可以显著促进氰酸酯树脂的固化反应;适量酚的加入能显著提高氰酸酯树脂体系的介电性但是会降低其玻璃化转变温度;含有壬基酚的氰酸酯树脂体系复合材料在宽频下表现出稳定的介电性。     

Environmental effects on thermoplastic and elastomer toughened cyanate ester composite systems

The effects of temperature and moisture on thermal and mechanical properties of high‐temperature cyanate ester composite materials were investigated. A resin transfer molding process was used to impregnate glass fiber fabrics with matrices that underwent thermoplastic or elastomeric toughness modifications. The elastomer‐modified material obtained the highest mode I fracture toughness values primarily because the toughener did not phase separate. Extended exposure to 200°C, however, deteriorated initial toughness improvements regardless of the modifier utilized. Although the thermal stability was increased by using thermoplastic modifiers in comparison to the elastomer‐modified material, the degradation was mainly governed by the cyanate ester network. Gaseous degradation products caused delaminations and therefore reduced strength when the materials were exposed to 200°C for 1000 h. Also, upon immersion in water at 95°C, the matrices absorbed up to 3.3 wt % more than previous values reported in the literature. Fiber/matrix interfacial phenomena were responsible for this behavior because fiber/matrix adhesion also was reduced drastically as shown by the strong reduction in flexural strength. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 556–567, 2000     

HBP-SiO2对氰酸酯树脂固化动力学的影响

为了提高nano-SiO2在树脂基体中的分散性,采用一种超支化聚硅氧烷修饰的纳米二氧化硅(HBP-SiO2)改性氰酸酯(CE)树脂。利用非等温差示扫描量热法(DSC)研究了HBP-SiO2/CE电子封装材料的固化动力学,求得其固化工艺参数和固化动力学参数分别为:凝胶温度150.17℃,固化温度197.81℃,后处理温度258.97℃;表观活化能11.22kJ/mol,反应级数0.75,频率因子18342.84s-1。研究表明,HBP-SiO2的加入可以降低CE的活化能,使其固化反应可以在较低温度下进行。     

Performance of aluminum borate whisker reinforced cyanate ester resin

Aluminum borate whisker (AlBw) treated with γ‐methacryloxypropyltrimethoxy silane (KH550) and borate ester (BE4) was adopted to modify bisphenol A dicyanate/epoxy resin (BADCy/E‐51) system, in this article. The influence of coupling agent and content of whisker on reaction activity were investigated by gel time and differential scanning calorimeter (DSC) and the results showed that addition of whisker enhances reaction activity of BADCy/E‐51 system slightly. The dispersion of whisker in matrix and reinforcement mechanism was investigated by scanning electron microscope (SEM). Results reveal that whisker treated with BE4 had better dispersing than that treated with KH550 in resin. The thermal stability, mechanical properties, and hot–wet resistance of AlBw/BADCy/E‐51 resin system were also studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Novel aluminum phosphate/cyanate ester composites: Thermodegradation behaviors and kinetic analyses

Thermodegradation behaviors of novel aluminum phosphate/cyanate ester (AlPO₄(KH550)/CE) composites were studied in detail. Results show that thermodegradation behaviors and kinetic parameters of AlPO₄(KH550)/CE composites are greatly dependent on the AlPO₄(KH550) loading. The addition of AlPO₄(KH550) into CE resin changes the thermodegradation mechanism (mainly at the temperature lower than 450°C) and degradation process from two steps to three steps. Comparing with CE resin, AlPO₄(KH550)/CE composites have lower initial degradation temperature and greatly higher char yield. Besides, for each thermodegradation step, the more the AlPO₄ content, the smaller the activation energy value is. All reasons leading to these outcomes are investigated intensively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

双马来酰亚胺改性氰酸酯树脂及其复合材料

制备了一种新型的双马来酰亚胺改性氰酸酯树脂以提高这类树脂的耐热性,力学性能及成型工艺性。对合成的树脂作了流变分析,对其玻纤复合材料进行了力学性能测试和热失重分析,结果表明,当双马树脂达到改性氰酸酯树脂的质量分数的37.5%时,新型改性氰酸酯树脂的5%热失重温度为432℃。改性氰酸酯基复合材料在常温条件下的拉伸强度为492.4 MPa,弯曲强度为526.3 MPa。在200℃时改性氰酸酯基复合材料的拉伸强度为357.3 MPa,弯曲强度为292.7 MPa。该树脂具有良好的加工性,耐热性,力学性能及高温力学保持性。     

Preparation and properties of maleimide‐functionalized hyperbranched polysiloxane and its hybrids based on cyanate ester resin

A new hyperbranched polysiloxane containing maleimide (HPMA) was synthesized through the reaction between N‐(4‐hydroxyphenyl) maleimide and 3‐glycidoxypropyltrimethoxysilane, which was then used to prepare cyanate ester (CE) resin‐based hybrids (coded as HPMAx/CE, where x is the weight fraction of HPMA in the hybrid). The curing behavior of uncured hybrids and the typical properties (impact strength and dielectric properties) of cured hybrids were systemically investigated. Results show that the performance of hybrids is greatly related with the content of HPMA. Hybrids have obviously lower curing temperature than CE, overcoming the poor curing characteristics (higher curing temperature and longer curing time) of neat CE, for example, the curing peak temperature of HPMA20/CE is about 65°C lower than that of CE. In the case of cured resin and hybrids, the hybrids exhibit decreased dielectric constant and loss than CE resin; moreover, the former also exhibits lower water absorption than the latter. Specifically, the dielectric loss of HPMA15/CE hybrid is only about 27% of that of neat CE resin. In addition, the hybrids with suitable contents of HPMA have significantly improved impact strengths. The overall improved properties suggest that HPMAx/CE hybrids have great potential in applications needing harsh requirements of curing feature, dielectric properties, and toughness. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Novel modification of cyanate ester by epoxidized polysiloxane

A novel modification of cyanate ester (CE) resin by epoxidized polysiloxane (E‐Si) has been developed, and the modified system is coded as CE/E‐Si. E‐Si was prepared by the reactions among octamethylcyclotetrasiloxane, hexamethyldisiloxane, (3‐aminopropyl)‐methyldiethoxysilane, and diglycidyl ether of bisphenol‐A resin. Six formulations were designed to evaluate the effect of the weight ratio between CE and E‐Si on performance parameters. Results reveal that the addition of E‐Si in CE resin cannot only significantly decrease the curing temperature of the CE resin but also improve the water resistance and toughness of original CE resin. Moreover, these positive effects increase with the increase of E‐Si concentration in CE/E‐Si systems. Thermal property investigation shows that the glass‐transition temperature and initial degradation temperature of CE/E‐Si systems are lower than that of original CE resin. For the flexural properties of the CE/E‐Si systems, the E‐Si concentration in the system exists a threshold, that is, when the E‐Si concentration is smaller than the threshold, original CE and CE/E‐Si systems have similar flexural properties, whereas when the E‐Si concentration is higher than the threshold, CE/E‐Si systems have lower flexural properties than original CE resin. All these changes of properties are closely correlated to the structure alteration from neat CE to CE/E‐Si networks. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

纳米TiO_2/纳米ZnO杂化改性内墙涂料的研究

采用物理掺和法,在不同内墙涂料中加入纳米TiO2和纳米ZnO,制备纳米复合涂料,进行抗菌试验和甲醛降解实验。结果表明,随着纳米粒子杂化含量的增加,甲醛降解能力和抗菌性能增强,当1#内墙涂料∶纳米TiO2∶纳米ZnO含量比=100∶1.6∶1.6;2#内墙涂料∶纳米TiO2∶纳米ZnO含量比=100∶1.8∶1.8时,效果最好。     

Combustibility of cyanate ester resins

Flaming and non‐flaming combustion studies were conducted on a series of polycyanurates to examine the effect of chemical composition and physical properties on the fire behavior of these crosslinked, char forming, thermoset polymers. Heats of complete combustion of the polymer and fuel gases were determined by oxygen bomb calorimetry and pyrolysis‐combustion flow calorimetry, respectively. Fire calorimetry experiments were conducted to measure the total heat released, the rate of heat release and the smoke generation in flaming combustion. Fire response parameters derived from the data include the thermal inertia, heat of gasification, effective heat of combustion and combustion efficiency. Halogen‐containing polycyanurates exhibited extremely low heat release rate in flaming combustion compared with the hydrocarbon resins yet produced significantly less smoke and comparable levels of carbon monoxide and soot. Published in 2005 by John Wiley & Sons, Ltd.