5528氰酸酯树脂性能研究

对新型的5528改性氰酸酯树脂的介电性能、耐热性能、粘温特性和吸湿性能进行了研究,结果表明:5528氰酸酯树脂具有良好工艺性能,适合于湿法预浸和热熔预浸,介电性能优异,介电损耗正切值为0.005 26,远远低于纯氰酸酯固化物,而且对于频率的稳定性更好,适合宽频应用5。528氰酸酯树脂体系是适合高性能透波材料或高频印刷电路板应用的树脂基体。     

高频氰酸酯基覆铜板基板的研制

采用有机锡催化剂固化氰酸酯，利用未固化树脂的凝胶曲线和DSC曲线确定树脂的固化工艺。表征固化树脂和复合材料的力学性能，测试其介电性能。结果表明在1GHz频率下，高频氰酸酯基覆铜板基板的介电常数和介电损耗角正切值分别为2．8和0．006，水煮对其性能影响较小，表现出优异的耐水煮和耐湿热老化性能，能够很好地满足高频印刷电路板的要求。     

石英纤维增强氰酸酯树脂基复合材料性能研究

研究了QF210石英纤维增强新型的改性氰酸酯树脂基复合材料的耐热性、力学性能和介电性能,结果表明5528A／QF210复合材料具有优良的力学性能和优异的介电性能,可在150℃下使用。尤其是5528A／QF210复合材料的介电性能具有极好的频率稳定性,适合作为宽频高透波材料。     

PBO纤维与石英纤维混编增强氰酸酯树脂基复合材料的研究

结合PBO纤维增强树脂基复合材料优异的介电性能和石英纤维增强树脂基复合材料优异的力学性能,本文设计了石英纤维与PBO纤维体积比55∶45混合编织,同时采用空气气氛对混编纤维表面进行等离子体处理,等离子体处理工艺为400W/10min,制备的氰酸酯树脂复合材料力学性能较纯PBO纤维增强氰酸酯树脂复合材料具有更加优异的性能,弯曲强度提高了62%,层间剪切强度提升了231%,大大加快了PBO纤维复合材料在透波复合材料领域的应用步伐。     

脱蜡处理对石英布/氰酸酯复合材料的性能影响

对石英纤维布进行了高温脱蜡处理,并制成了石英布增强氰酸酯树脂基预浸料及其复合材料,对比了脱蜡处理前后预浸料的理化性能和工艺性的变化,以及复合材料介电性能和力学性能的变化。结果表明,脱蜡处理后的石英布/氰酸酯预浸料的工艺性能更好,复合材料的介电性能保持不变,力学性能显著提高,其中弯曲强度提高31%,层间剪切强度提高16%,脱蜡后界面结合更好。     

纤维增强PBT复合材料的性能研究

本文以玄武岩纤维(BF)、低介电玻璃纤维(DGF)和无碱玻璃纤维(EGF)为增强材料,采用双螺杆挤出,制备了增强PBT复合材料,研究了不同的纤维材料对PBT复合材料的机械性能、热性能和介电性能的影响。结果表明,BF、DGF、EGF均能有效提高PBT复合材料的机械性能和耐热性,但会增加材料的介电常数。DGF增强PBT复合材料的综合性能最优,介电常数和介电损耗角正切值最低;BF能明显提高PBT复合材料的耐热性,效果优于DGF和EGF,且不影响PBT材料的结晶性能。     

酚醛型环氧树脂改性氰酸酯复合材料性能的研究

通过DSC分析,粘度、介电性能、力学性能及耐油性测试对酚醛型环氧树脂改性氰酸酯树脂复合材料的性能进行了研究。结果表明,改性氰酸酯树体系在70～160℃具有较低的粘度,理想工艺是在125～130℃下30～45min后开始加压;改性氰酸酯树脂表观活化能和反应级数分别为60.81kJ/mol和0.8846。改性氰酸酯复合材料具有良好的力学性能、介电性能和耐油性能。     

二甲基对苯二甲基型氰酸酯的合成与性能研究

以对苯二甲基二甲醚为原料合成了二甲基对苯二甲基型苯酚（DMPXPh）。采用氯化氰-酚方法制备出新型二甲基对苯二甲基型氰酸酯（DMPXCy）,并测定了其结构。考察了材料的热性能、耐湿热性、介电性能和力学性能,并与双酚A型氰酸酯（BADCy）进行比较。研究结果表明：（1）红外和核磁氢谱表征证明已经成功地制备出目标酚中间体,并且酚中间体已被氰酸酯化制备成氰酸酯单体。（2）DMPXCy的固化行为和热性能研究表明,DMPXCy反应活性低于BADCy树脂,并且加入有机金属催化剂后,固化温度明显降低,可在280℃内阶梯固化。另外,DMPXCy树脂的玻璃化转变温度比BADCy树脂低,热稳定性基本相同,但DMPXCy的残炭率较高,显示出一定的耐烧蚀性。（3）力学性能研究表明,DMPXCy树脂总体力学强度与BADCy相近,拉伸强度略低。（4）DMPXCy树脂吸湿性和介电性能研究说明,DMPXCy树脂展现出优异的介电性能和低吸湿性,介电常数（ε）与介电损耗角正切（tanδ）分别为2.650和0.004 50,饱和吸湿率为0.70%,远低于BADCy树脂的介电损耗和吸湿率。DMPXCy树脂作为低介电透波材料或...     

共聚改性氰酸酯树脂及其性能

利用环氧树脂和双马来酰亚胺树脂做改性剂,对氰酸酯树脂进行共聚改性,通过对粘度的测量描述了共聚树脂的固化反应情况。性能测试表明内聚改性氰酸酯树脂的冲击强度比纯氰酸酯树脂自聚体提高了2倍多,可达12.3kJ/cm^2,热变形温度高达235℃,并具有优异的介电性能,如10kHz 介电常数为2.25,介电损耗角正切＜10^-4。共聚树脂中的配比和固化条件对性能有影响。     

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。     

Dielectric properties of polymer/ceramic composites based on thermosetting polymers

Summary A series of thermosetting polymer/ceramic composites were prepared. Three kinds of thermosetting polymers, i.e. cyanate resin, bismaleimide resin, and epoxy resin, were used as matrixes, and BaTiO₃ particles were as fillers. The dielectric properties of these composites were investigated. Experimental data of the dielectric constants were fitted to several theoretical equations in order to obtain the best-fitting equations of the dielectric constants of these composites. The result indicates that the dielectric constants of composites all increase with the increase of BaTiO₃ content. Using bismaleimide resin and epoxy resin as matrixes, the dielectric losses both increase obviously as the amount of BaTiO₃ particles is increased, but the dielectric loss of cyanate/BaTiO₃ composite decreases. With the increase of the frequency, the variation ranges of the dielectric constant and dielectric loss of cyanate/BaTiO₃ composite are both the smallest. The predications of the effective dielectric constants by Lichterecker mixing rule are in good agreement with experiment data.     

Novel high‐performance wave‐transparent aluminum phosphate/cyanate ester composites

Advanced wave‐transparent composites are the key materials for many cutting‐edge industries including aviation and aerospace, which should have outstanding heat resistance, low dielectric constant and loss as well as good mechanical properties. A novel kind of high‐performance wave‐transparent composites based on surface‐modified aluminum phosphate AlPO₄(KH‐550) and cyanate ester (CE) was first developed. The dielectric and dynamic mechanical properties of AlPO₄(KH‐550)/CE composites were investigated intensively. Results show that AlPO₄(KH‐550)/CE composites have decreased dielectric loss and higher storage moduli than pure CE resin; in addition, the composites with suitable AlPO₄(KH‐550) concentration remain the outstanding thermal property and low dielectric constant of pure CE resin. The reasons attributing to these results are discussed from the effects of AlPO₄(KH‐550) on the key aspects such as morphology, curing mechanism, and interfacial adhesion of composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The origin of the electric and dielectric behavior of expanded graphite–carbon nanotube/cyanate ester composites with very high dielectric constant and low dielectric loss

High performance expanded graphite (EG)–multiwalled carbon nanotube (MWCNT)/cyanate ester (CE) composites with very high dielectric constant, low dielectric loss and low percolation threshold were developed. In order to understand the electric and dielectric behavior of EG–MWCNT/CE composites, EG/CE and MWCNT/CE binary composites were also prepared for comparison. Results show that the ternary composites have greatly different electric and dielectric properties from the binary composites. The percolation threshold of the EG–MWCNT/CE composite is much lower than that of either the EG/CE or MWCNT/CE composite. With the same content of conductive fillers, the EG–MWCNT/CE composite shows a much higher dielectric constant than EG/CE and MWCNT/CE composites. In addition, to obtain the same dielectric constant, the dielectric loss of the EG–MWCNT/CE composite is lower than that of either binary composite. The difference is attributed to the synergistic effect between EG and MWCNT. The addition of EG not only improves the dispersion of MWCNTs in the resin matrix, but also helps to form conductive networks. An equivalent circuit model is proposed.     

多步接枝稀土掺杂/氰酸酯树脂基复合材料固化性能研究

通过多步接枝制得系列表面有机化的掺杂TiO2粒子(M系列粒子),制备了系列氰酸酯树脂(CE)基复合材料。结果表明,M系列掺杂粒子的引入,在降低复合材料活化能,有利于复合材料固化成型的同时,未改变复合材料的固化机理。定量M系列粒子(质量分数≤3%)的引入,优化了复合材料的介电性能,使复合材料介电常数增大66.2%,介电损耗减小50%。     

环氧树脂基介电复合材料的制备和性能研究

以环氧树脂(EP)为基体树脂、经硅烷偶联剂改性后的压电陶瓷钛酸钡(BaTiO3)为增强填料,采用浇铸法制备了有机/无机介电复合材料。研究了填料用量对复合材料介电性能、力学性能和热性能的影响。实验结果表明,BaTiO3能显著提高材料的介电常数,当w(BaTiO3)=60%时,复合材料的介电常数为23.6,比纯EP的介电常数(4.0)提高了近6倍,而且复合材料的介电常数受频率影响较小,具有较好的频率稳定性;随着BaTiO3含量的增加,材料的弯曲强度和冲击强度都呈先增后减的趋势,最大弯曲强度和冲击强度分别为123.8 MPa和26.3 kJ/m2;材料的热稳定性研究表明,材料的起始热分解温度随着BaTiO3含量的增加而提高,材料的耐热性能得到改善。     

Investigation on curing reaction of phthalonitrile resin with nanosilica and the properties of their glass fiber-reinforced composites

In this work, Phthalonitrile containing benzoxazine (BA-ph) and Bisphenol A based cyanate ester (CE) were chosen as the matrix resin. Various amount of nano-SiO₂ was incorporated into BA-ph/CE and their glass fiber-reinforced composite laminates were fabricated. Curing reaction and processability of BA-ph/CE/SiO₂ blends were studied by differential scanning calorimetry and dynamic rheological analysis. Results showed that BA-ph and CE exhibited good processability and curing reaction of BA-ph/CE was not obviously affected by SiO₂. Scanning electron microscope images of the composites showed that SiO₂ particles were well dispersed in BA-ph/CE matrix. Moreover, SiO₂ could act as physical crosslinking points and diluent in matrix as well as between the glass fibers to improve the mechanical properties of composite laminates. As the results of dynamic mechanical analysis and thermogravimetry analysis, composite laminates possessed satisfactory T_g and good thermal stability. With incorporation SiO₂ particles into matrix resin, dielectric constant and dielectric loss of BA-ph/CE/SiO₂/GF composites were increased and showed frequency dependence.     

玻璃纤维布增强EP/PPO复合材料性能及应用

利用材料试验机、扫描电镜、高频微波仪及差示扫描量热仪研究了玻璃纤维布增强环氧树脂(EP)/聚苯醚(PPO)复合材料的弯曲性能、相态、介电性能和耐热性。结果表明,树脂含量对EP/PPO复合材料的弯曲强度和介电性能影响很大,在树脂质量分数约为40%时,复合材料的弯曲强度最大;当树脂质量分数大于30%时,介电常数的理论预测值与实验结果基本符合;硅烷偶联剂KH-550处理玻璃纤维布制得复合材料的弯曲性能较优;玻璃纤维布增强EP/PPO复合材料的热性能比纯EP/PPO树脂的热稳定性好。