纳米Si_3N_4/氰酸酯树脂电子封装材料的研究

采用硅烷偶联剂(KH-560)对nano-Si3N4进行表面处理,然后以此作为4,4′-二氰酸酯基二苯基甲烷(BCE)的改性剂,制备了nano-Si3N4/BCE电子封装材料,并研究了该体系的静态力学性能、动态力学性能以及介电性能。结果表明:nano-Si3N4的加入提高了材料的冲击强度和弯曲强度,当w(nano-Si3N4)=3%时,冲击强度、弯曲强度分别由纯BCE的10.1 kJ/m2和94.11 MPa提高到14.58 kJ/m2和112.13 MPa;Nano-Si3N4/BCE体系的储能模量在低温区略低于纯BCE体系,在高温区则略高于纯BCE体系;改性体系的介电常数高于纯BCE体系,但介电损耗因子则低于纯BCE体系。     

Liquid crystalline epoxy resin modified cyanate ester for high performance electronic packaging

A high performance modified cyanate ester (CE) resin system with significantly improved toughness, water resistance and dimensional stability was developed by copolymerizing CE resin with liquid crystalline epoxy resin (LCE) for electronic packaging. Four LCE/CE resins with different contents of LCE were prepared to systemically evaluate the effect of the content of LCE on the key properties of the modified system such as mechanical, dielectric and thermal properties as well as water resistance. Results reveal that the addition of LCE to CE can not only decrease the curing temperature of CE, but also significantly improve the integrated properties including mechanical and dielectric properties, thermal resistance as well as water resistance of cured resin. For example, compared with the whole exothermic peak of CE, that of LCE10/CE significantly shifts toward low temperature with a gap of about 15°C. On the other hand, the impact strength of cured LCE10/CE resin (22 kJ/m²) is about 2.1 times of that of CE resin; while the water absorption of the former is only 81.2% of that of the latter. In addition, cured LCE/CE resins also exhibit lower and more stable dielectric loss than CE resin over the whole frequency range from 10 to 10⁶ Hz. All these improvements in macro-performance by the addition of LCE to CE resin are not only ascribed to the cross-linked chemical structure, but also attributed to the rigid structure of liquid crystalline resin. The outstanding integrated properties of LCE/CE resins suggest great potential to be applied in the field of high performance electronic packaging.     

Fabrication and properties of CTBN/Si3N4/cyanate ester nanocomposites

Hybrid fillers of carboxyl‐terminated liquid butadiene‐acrylonitrile/silicon nitride (CTBN/Si₃N₄) are performed to regulate the mechanical properties, heat resistance properties, dielectric properties and thermal conductivities of the bisphenol A dicyanate ester (BADCY) resins. With the 10 wt% addition of CTBN/Si₃N₄ hybrid fillers, the maximum impact, and flexural strength of the CTBN/Si₃N₄/BADCY nanocomposite is increased to 15.4 kJ/m² and 144.3 MPa, respectively. And the corresponding thermal conductivity value of the CTBN/Si₃N₄/BADCY nanocomposite is increased to 0.622 W/mK with 18 wt% addition of CTBN/Si₃N₄ hybrid fillers. Moreover, with the addition of CTBN/Si₃N₄ hybrid fillers, the heat resistance properties of the CTBN/Si₃N₄/BADCY nanocomposites are increased, but the dielectric properties get worse slightly. POLYM. COMPOS., 37:2522–2526, 2016. © 2015 Society of Plastics Engineers     

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     

Biobased cyanate ester composites with epoxidized soybean oil and in situ generated nano‐silica

Biobased cyanate ester (CE) nanocomposites have been prepared from renewable resource, epoxidized soybean oil (ESO) and in situ generated nano‐silica via sol–gel process. The isothermal curing process was investigated by differential scanning calorimetry (DSC) and rheometry. The results indicate that the incorporation of silica accelerates the reaction at the beginning stage of curing process but descends the final isothermal curing conversion. The morphological study of nanocomposites by scanning electron microscope and transmission electron microscope suggests that the silica exists in the forms of both nanoparticles and silica networks, while the diameter of ESO‐rich phase diminished with the increase of silica loading. In addition, the thermal–physical and mechanical properties were evaluated by dynamic mechanical analysis, thermogravimetric analysis, and tensile mechanical test. The biobased CE nanocomposites show effectively improved properties compared to the systems without nano‐silica. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.     

纳米Si3N4粉末分散工艺研究

研究了纳米Si3N4粉末的分散性能,得到了优化的分散工艺参数.实验结果表明,将纳米Si3N4进行超声分散,可以改善其分散状况;加入适量的表面活性剂能改善Si3N4的分散效果,阳离子型表面活性剂的分散效果优于非离子型表面活性剂;分散体系的pH值也影响纳米Si3N4粉的分散效果.     

聚苯硫醚/纳米Si3N4复合材料的制备及性能研究

表面改性处理的纳米Si3N4粉体与聚苯硫醚（PPS）熔融共混挤出制成PPS/纳米Si3N4复合材料,通过拉伸、冲击实验及动态力学性能测试考察了纳米粉体加入量对复合体系各项性能的影响。结果表明,纳米Si3N4填充PPS基复合材料的力学性能明显优于纯PPS。随粉体添加量的增加,复合材料的拉伸强度增大,当添加量为0.8 %时,拉伸强度提高了22 %。随粉体添加量的增加,复合体系冲击强度增大,当粉体添加量为1.2 %时,冲击强度和缺口冲击强度出现最大值,分别比纯PPS增加了33 %和41 %。动态力学性能测试表明,随粉体添加量的增加,PPS分子链段松弛所需能量增加,松弛过程增长,体系储能模量降低,损耗模量增加。     

纳米氮化硅改性聚合物基复合材料研究进展

综述了纳米氮化硅( nano-Si3N4)改性聚合物(包括聚烯烃、环氧树脂、双马来酰亚胺、聚醚醚酮、聚苯硫醚、聚酯、聚四氟乙烯等)的研究进展,从热学性能、力学性能、结晶性能、摩擦性能和电性能等方面对nano-Si3N4改性聚合物的效果进行了叙述,并展望了nano-Si3N4改性聚合物的研究前景.     

纳米Si3N4／PP复合材料的力学性能研究

研究了纳米氮化硅（Si3N4）粒子对其填充的聚丙烯（PP）力学性能的影响,结果发现纳米Si3N4/PP复合材料的力学性能表现出了许多与常规纳米粒子改性PP的不同之处。复合材料的拉伸强度随纳米Si3N4粒子含量增加而基本呈直线上升趋势,而冲击强度变化不大,纳米Si3N。粒子对PP并无明显增韧效果;少量（5％）纳米Si3N4粒子便能显著提高复合材料弯曲强度。     

Morphological,mechanical and thermal properties of cyanate ester/benzoxazine resin composites reinforced by silane treated natural hemp fibers

This present study deals with the reinforcement of thermosetting resin blends composed of cyanate ester (CE) and benzoxazine (BOZ) resins with natural hemp fibers (NHFs). These NHFs were initially treated by using a silane coupling agent (SCA) in order to chiefly enhance their distributions as well as adhesions within the CE/BOZ resin matrix, then incorporated with various weight amounts ranging from 5 wt% to 20 wt% with a regular interval of 5 wt%. The obtained results showed that at the maximum treated fiber loading (20 wt%), distinctive enhancements in the mechanical properties in terms of flexural strength and microhardness were obtained. Besides, the thermal stability and glass transition temperature (T_g) were appreciably enhanced and were higher than those of the pure CE/BOZ resin properties. With respect to the astonishing properties of the NHFs, these enhancements could be possibly due to the good dispersion and adhesion of the treated NHFs inside the CE/BOZ resin achieved upon using the SCA. Therefore, we believe herein that these renewable and cheap NHFs have considerable potential to be used as reinfocer materials for CE/BOZ resin composites to be used in various industrial sectors.     

Preparation of boz/glass fibers/cyanate ester resins laminated composites

A novel kind of high performance laminated composites of Bis allyl benzoxazine/Quartz fibers/Cyanate ester (Bz‐ally/QFs/CE) have been developed. The effects of Bz‐ally on the moisture resistance, mechanical, dielectric, and thermal properties of Bz‐ally/QFs/CE laminated composites were investigated systematically. Compared with QFs/CE laminated composites, the flexural strength and the interlaminar shear strength value of the Bz‐ally/QFs/CE laminated composites were improved markedly with up to 25.2% and 22.3% increasing magnitude, respectively. Meanwhile, the Bz‐ally/QFs/CE laminated composites exhibit lower dielectric constant and loss than QFs/CE laminated composites over the testing frequency from 10 to 60 MHz. In addition, the thermal stability and moisture resistance of Bz‐ally/QFs/CE laminated composites were also superior to that of Boz/QFs/CE laminated composites. POLYM. COMPOS., 38:523–527, 2017. © 2015 Society of Plastics Engineers     

Preparation of POSS/Quartz fibers/cyanate ester resins laminated composites

Quartz fibers (QFs) and two polyhedral oligomeric silsesquioxane (POSS) (epoxy‐POSS and hydroxy‐POSS) are performed to regulate the dielectric properties, heat resistance, and mechanical properties of cyanate ester (CE) resins. With the introduction of POSS, the dielectric constant and dielectric loss tangent values of the POSS/QFs/CE laminated composites are decreased obviously. The heat resistance properties and flexural strength values of the laminated composites are increased, but the interlaminar shear strength values of the laminated composites are decreased slightly. The EP‐POSS/QFs/CE laminated composites have relatively better dielectric, heat resistance, and mechanical properties than those of HO‐POSS/QFs/CE laminated composites. POLYM. COMPOS., 36:2017–2021, 2015. © 2014 Society of Plastics Engineer     

Structure and properties of multiwalled carbon nanotubes/cyanate ester composites

Two types of multiwalled carbon nanotubes (MW‐CNTs) with different structure and morphology were used to fabricate cyanate ester (CE) matrix composites. Mechanical, thermal, and transmission electron microscopy tests were performed to evaluate the different effects of the two types of MW‐CNTs on the structure and properties of MW‐CNT/CE composites. Results showed that the bundled MW‐CNTs were easier to be dispersed in CE matrix than single MW‐CNTs, and could improve the toughness and stiffness of CE material more significantly. Functionalization of the two types of MW‐CNTs, which was achieved by grafting triethylenetetramine groups onto the surface of MW‐CNTs, was helpful in improving the dispersion of the MW‐CNTs in CE, and thus in fabricating MW‐CNT/CE composites with improved mechanical and thermal properties. POLYM. ENG. SCI. 46:670–679, 2006. © 2006 Society of Plastics Engineers     

Mechanical and Tribological Properties of a Nano-Si3N4/Nano-BN Composite

The mechanical and tribological properties of a nano-Si₃N₄/nano-BN composite were studied. The composite was prepared via high-energy mechanical milling and subsequent spark plasma sintering. Y₂O₃ and Al₂O₃ were used as sintering additives. After sintering, the average crystalline size of Si₃N₄ and BN was 50 nm. Hardness (Vicker and Knoop) was evaluated under a high load of 0.05–2.0 kg for the nano/nano- and the micro/micro-Si₃N₄/BN composite with the same composition. The indentation fracture toughness values of both composites were also evaluated. Tribological studies were conducted to study the friction and wear behavior of both composites. A friction coefficient of 0.4–0.7 was obtained for the nano-S₃N₄/nano-BN composite under a normal load of 20–22 N, whereas, a friction coefficient of 0.37 was obtained for the micro-Si₃N₄/micro-BN composite. Specific wear coefficients of 0.418 × 10⁻⁴ and 0.625 × 10⁻⁴ mm³/N/m were obtained for nano-sized and micro-sized Si₃N₄/BN composites, respectively. Higher hardness, higher fracture toughness, and lower wear were observed in the nano-sized composite, as compared with the micro-sized composite.     

Mechanical properties of high temperature cyanate ester/BMI blend composites

A new Schiff base functionalized dicyanate ester was synthesized and the monomer was characterized by FTIR, ¹H-NMR, ¹³C-NMR and elemental analysis techniques. This prepared dicyanate ester with catalyst was then blended with BMI resin at different ratios by solution technique. The composites were made by impregnating the fibers with the blend solution followed by curing at various time-temperature schedules. The mechanical properties of the blend composites were tested. The fiber volume fraction of the composites were found to be in the range 41 ± 3%. The mechanical properties such as tensile modulus (32–35 GPa), flexural modulus (56–59 GPa) and Mode I fracture toughness (G_IC = 104–136 J/m²) and impact response (1,121–1,218 J/m) were found to increase with increasing cyanate ester content in the Cy/BMI blends. From the DMA study it was observed that as the cyanate content increases from 3 to 9% in the blend the tan δ value increases from 0.112 to 0.126 and the storage modulus decreases from 24,750 to 22,870 MPa indicating that the crosslink density of the blends decreases. The SEM analysis shows the absence of phase separation. Moisture absorption and chemical resistance of the blend composites increase with increasing cyanate content. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers     

Bisphenol S and bisphenol A cyanate ester/barium metaborate composites

The aim of this study was to improve thermal stability and surface properties of bisphenol A dicyanate ester (BADCy) by adding bisphenol S dicyanate ester (BSDCy) and Ba(BO₂)₂. Bisphenol S and bisphenol A cyanate ester/barium metaborate composites having various ratios of BADCy, BSDCy, and Ba(BO₂)₂ were prepared. Thermal stability of the samples was evaluated by thermogravimetric analysis and differential scanning calorimetry. Hydrophobicity of the samples was determined by the contact angle measurements. The samples were characterized with the following analysis; gel content, water absorption capacity. Moreover, the surface morphology of the samples was investigated by a scanning electron microscopy. The obtained results prove that the cyanate ester containing sulfonyl/Ba(BO₂)₂ composites have good thermal and surface properties and they can be used in many applications such as electronic devices, materials engineering, and other emergent. POLYM. COMPOS., 37:1312–1317, 2016. © 2014 Society of Plastics Engineers     

A novel biobased resin‐epoxidized soybean oil modified cyanate ester

Cyanate ester (CE) resin was modified with renewable resource, i.e. epoxidized soybean oil (ESO), and the effects of ESO content on the curing co‐reaction, morphologies, water absorption behaviors, thermal and mechanical properties of CE/ESO blends were studied. Differential scanning calorimeter (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA) were employed to characterize the ESO‐modified CE polymer networks. Homogeneous structures were observed for low‐content of ESO modified CE systems by SEM, while ESO‐rich particles were observed in the modified systems with ESO above 15 wt %. The blend of the CE and ESO resulted in an excellent combination as a new biobased thermoset material having relatively high mechanical properties with 15 and 20 wt % ESO as replacement of CE. Enhanced elongations at break were observed for the modified systems while the tensile strengths kept about the same level at the same time. The storage moduli and glass transition temperatures of the modified systems in the glassy state and rubber plateau were observed to be lower than those of neat CE with the increase of ESO weight percent. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

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。     

环氧基硅烷改性氰酸酯树脂的性能研究

采用环氧基硅烷(ESi)对双酚A型二氰酸酯树脂(BCE)进行改性,研究了ESi用量对ESi/BCE体系力学性能和动态力学性能等影响。结果表明:适量的ESi可以明显提高BCE的韧性和强度;当w(ESi)=6%时,ESi/BCE改性体系的力学性能最好,其冲击强度和弯曲强度分别从10.1 kJ/m2、94.11 MPa提高到14.49 kJ/m2、110.94 MPa;ESi/BCE体系的交联密度降至适度是其韧性提高的主要原因,并且其玻璃化转变温度(Tg)低于纯BCE体系(但降幅不大)。     

石墨烯/环氧树脂改性氰酸酯复合材料的微波吸收性能

采用溶液共混法制备了TNGNP(石墨烯)/EP(环氧树脂)改性CE(氰酸酯)复合材料。利用红外光谱(FT-IR)法和扫描电镜(SEM)等对该复合材料的结构和微观形貌进行了表征,并采用矢量网络分析仪对其复介电常数进行了测定。研究结果表明:该复合材料的复介电常数随TNGNP掺量增加而增大;当w(TNGNP)=3%(相对于复合材料质量而言)时,该复合材料的反射损耗绝对值大于10 d B的频率覆盖范围为5.8~6.6 GHz,其最大反射损耗绝对值为15.7 d B;该复合材料的强吸收特性表明其作为微波吸收材料具有良好的潜在应用前景。