氰酸酯树脂/聚甲基丙烯酸甲酯合金的异步合成及表征

采用异步合成法,将经过预聚的聚甲基丙烯酸甲酯(PMMA)接枝到双酚A型氰酸酯树脂(BADCy)中制备BADCy/PMMA合金材料。对合金材料进行力学性能测试和动态热机械分析,研究了不同PMMA含量对合金材料弯曲、冲击性能及玻璃化转变温度(Tg)的影响。利用傅立叶变换红外光谱和扫描电子显微镜对其结构和形态进行了分析与表征。结果表明,PMMA接枝到了BADCy的分子链上,形成了半互穿网络结构;随PMMA含量的增加,合金材料的弯曲强度、弯曲弹性模量和冲击强度总体上呈先上升后降低的趋势,当PMMA质量分数为15%时,弯曲强度和弯曲弹性模量分别达到最大,其值为196.29 MPa和9.83 GPa,比纯BADCy提高了74.5%和92.0%;当PMMA质量分数为20%时,冲击强度达到最大值17.95 kJ/m2,比纯BADCy提高了88.3%,此时材料冲击断面呈现出典型的韧性断裂特征。与纯BACDy相比,合金材料的Tg略有降低。     

氰酸酯/聚甲基丙烯酸甲酯互穿聚合物网络的探究

用同步法合成了氰酸酯/聚甲基丙烯酸甲酯(CE/PMMA)互穿聚合物网络(IPN),研究了甲基丙烯酸甲酯(MMA)含量对CE/PMMA-IPN体系力学性能及密度的影响。结果表明CE/PMMA-IPN体系的性能比单一树脂的优异。     

聚甲基丙烯酸甲酯(PMMA)对氰酸酯树脂(BADCy)力学性能和热性能的影响

通过异步合成法,将预聚的聚甲基丙烯酸甲酯(PMMA)用于改性双酚A型氰酸酯树脂(BADCy),制备了改性BADCy。文章通过对材料进行弯曲强度、冲击强度、动态热机械分析(DMA)、SEM、FTIR分析,探讨不同PMMA添加量对改性BADCy力学性能的影响。结果显示,与纯BADCy相比,当PMMA的质量分数为20%时,改性BADCy弯曲强度和冲击强度分别提高58.5%和88%,环氧树脂(EP)与BADCy相分离消失,玻璃化温度(Tg)基本保持不变,同时改性BADCy的粘性较低,有助于固化浇铸成型。通过使用TGA、DSC等测试手段探讨不同PMMA添加量对材料热性能的影响。结果表明,当PMMA质量分数为20%时,改性BADCy的热失重温度、质量保持率基本不变,固化热降低,反应可控性增强。     

BADCy/PAN互穿网络的合成及表征

采用同步合成法和异步合成法分别制备双酚A型氰酸酯树脂/聚丙烯腈半互穿聚合物网络(BADCy/PAN-SIPN),研究了几种不同组分的SIPN体系.结果表明,BADCy/PAN-SIPN网络体系的形成对体系的力学性能和耐热性能都有较大的提高,当丙烯腈质量分数为15％时,SIPN体系的冲击强度提高了89.7％,弯曲强度提高...     

乙烯基氰/氰酸酯树脂半互穿网络的合成及表征

采用同步合成法和异步合成法分别制备半互穿聚合物网络-氰酸酯树脂/聚乙烯基氰(BADCy/PAN-SIPN)高分子材料,研究了几种不同组分的SIPN体系。结果表明,BADCy/PAN-SIPN网络的形成对体系的力学性能和耐热性能等有较大的提高,并提出了较合理的制备工艺条件     

BADCy/PSt互穿网络的合成及表征

用同步合成法和异步合成法分别制备半互穿聚合物网络———氰酸酯树脂/聚苯乙烯(BADCy/PSt-SIPN)高分子材料,研究了几种不同组分的SIPN体系。结果表明,BADCy/PSt-SIPN网络的形成对体系的力学性能和耐热性能有较大的提高。给出了较合理的制备工艺条件。     

多壁碳纳米管改性氰酸酯树脂体系的研究

针对环氧树脂(DGEBA)／双酚A型氰酸酯树脂(BADCy)体系,采用多壁碳纳米管(MWNTs)对其增韧改性,制备了MWNTs/ DGEBA／BADCy复合材料。利用透射电子显微镜(TEM)观察MWNTs在树脂中的分散情况,研究了MWNTs的用量对复合材料性能的影响,借助凝胶时间和扫描电子显微镜(SEM)对碳纳米管增强氰酸酯树脂的机理进行初步的探讨。研究表明:当碳纳米管的质量分数为1％时,复合材料的力学性能达到最佳,弯曲强度和冲击强度分别提高约15％和8％。     

氰酸酯／聚甲基丙烯酸甲酯半互穿网络实验探究

将氰酸酯(CE)加热溶解,混合搅拌至均匀,然后加入引发剂BPO,单体MMA,使它们发生本体聚合,用同步合成法制备半互穿聚合物网络(Semi-IPN)氰酸酯/聚甲基丙烯酸甲酯复合材料,通过制备几种不同组分的Semi-IPN体系进行研究,结果表明CE／PMMA-Semi-IPN网络形成的反应条件对体系的力学性能和密度影响很大。通过探讨后发现其工艺条件还有待进一步改进。     

E-51环氧树脂改性双酚A型氰酸酯树脂的研究

采用示差扫描量热法(DSC)、傅里叶变换红外光谱(FTIR)研究了E-51环氧树脂改性双酚A型氰酸酯树脂(BADCy)体系的反应活性、反应机理及固化工艺,通过TGA分析了不同含量E-51环氧树脂改性BADCy后固化物的热性能,并测定了体系的吸水率及力学性能。结果表明,随着E-51环氧树脂用量的增加,BADCy改性体系的反应活性逐渐提高,固化温度逐渐降低;用环氧树脂改性BADCy生成了恶唑烷酮等芳杂环结构,降低了氰酸酯树脂体系的三嗪环交联密度,增加了体系的韧性;改性后材料的起始热分解温度均在380℃以上,吸水率均低于2%。     

纳米SiO2改性BOZ/BMI/BADCy共聚物的制备及性能研究

研究了纳米SiO2含量对苯并恶嗪树脂(BOZ)/双马来酰亚胺(BMI)/双酚A型氰酸酯(BADCy)/纳米SiO2复合材料力学性能、热性能和吸水性能的影响。结果表明,当纳米SiO2质量分数为3%时,BOZ/BMI/BADCy/纳米SiO2复合材料具有较高的强度和良好的韧性,其缺口冲击强度和弯曲强度比BOZ/BMI/BADCy共聚物分别提高了11.6%和8.5%;同时,纳米SiO2质量分数为3%时BOZ/BMI/BADCy/纳米SiO2复合材料具有优异的耐热性,其初始热分解温度和最大热分解温度分别为343.2℃和430.3℃。     

Mechanical and thermal properties of bisphenol A-based cyanate ester and diallyl phthalate blends

Cyanate ester resins are a high performance class of compounds. They have excellent mechanical properties, dielectric properties and thermal properties; however, their major drawback is their brittleness. An attempt was made to improve the impact strength of the cyanate ester resin. In the present study a commonly used cyanate resin, bisphenol A dicyanate (BADCy), was modified by the addition of diallyl phthalate (DAP) and was cured with benzoyl peroxide. The properties of the blends such as thermal and mechanical properties were investigated in detail by scanning electron microscope, dynamic mechanical analysis, thermogravimetric analysis, and mechanical measurement. The results indicate that the addition of the appropriate amount of DAP can effectively improve the impact toughness and the flexural strength while sacrificing the thermal properties of the blends. The maximum impact strength and flexural strength were observed on addition of 15 phr DAP content. However, the thermal stability of the blends was found to be lower than that of the unmodified BADCy resin.     

环氧树脂改性氰酸酯树脂的研究

在保持氰酸酯树脂优良介电性能的前提下,用E44环氧树脂与双酚A型二氰酸酯共聚来改善氰酸酯树脂的力学性能。采用DSC研究了纯氰酸酯树脂、环氧树脂含量不同的共聚物的固化过程,发现环氧树脂能降低共聚体系固化温度。力学性能测试结果表明:环氧树脂对氰酸酯起到了增韧作用,当含量为30%时,拉伸强度、弯曲强度和压缩强度提高的幅度最大。断面SEM表明:环氧树脂的加入,使树脂体系韧性明显提高,不仅有大量韧性断裂纹出现,而且还有方向相互垂直的断裂纹。介电常数测试结果显示:环氧树脂的加入对树脂体系介电常数有明显影响,但仍能保持在4.5左右。     

双酚A型氰酸酯泡沫塑料的制备与性能

以双酚A型氰酸酯树脂（BADCy）为主要原料,采用模塑成型法制备了氰酸酯泡沫塑料（CEF）,并考查了所得泡沫的化学结构、泡孔结构、热性能和力学性能等。结果表明,体系的最佳反应条件为155 ℃/2 h + 200 ℃/2 h,制得的CEF泡孔均匀,为闭孔结构;泡沫塑料的玻璃化转变温度（Tg）为263 ℃,失重5 %的热分解温度为344 ℃; CEF的压缩模量和压缩强度分别与ρ1.043和ρ2.204存在线性关系。     

Cyanate ester resin modified by phenolic resin containing diphenyl oxide segments with high molecular weight

To obtain modified cyanate ester (CE) with good comprehensive properties and low cost, a novel phenolic resin containing diphenyl oxide (MPF) with high molecular weight was synthesized from diphenyl ether, formaldehyde, methanol and phenol by a two-step process which differed from polyphenylene oxide (PPO) in structure. The curing reaction and properties of the modified 2,2-bis(4-cyanatophenyl) propane (bisphenol-A-based cyanate ester, BADCy) by MPF were investigated. It was found that the curing temperature of the modified CE was lower than that of the unmodified CE. When the ratio of MPF and BADCy was 3:7, the cured resin exhibited low dielectric constant (3.00), low dielectric loss (0.0062) and high impact strength (12.5 kJ/m²), and its T _d5% was 371 °C, being superior to CE in the comprehensive properties. When the content of MPF was above 30 %, MPF/BADCy had poor comprehensive properties. In order to improve MPF/BADCy with high content of MPF, epoxy resin (E51) was added. When the ratio of MPF, BADCy and E51 was 50:50:67, the cured resin exhibited low dielectric constant (2.96), dielectric loss (0.0078) and high impact strength (11.84 kJ/m²), and its T _d5% was 365 °C. Small content of MPF or the combination of E51 and MPF were good for BADCy to improve its comprehensive properties.     

改性氰酸酯类耐高温胶粘剂的研究

以双马来酰亚胺(BMI)、双酚A型氰酸酯(BADCy)和苯并噁嗪(BOZ)树脂为基体树脂,纳米二氧化硅(nano-SiO2)为填料,制备耐高温胶粘剂。采用非等温差示扫描量热(DSC)法、Kissinger法和Ozawa法研究了nano-SiO2/BOZ/BMI/BADCy共聚物的固化动力学过程。结果表明:当m(BOZ)∶m(BMI)∶m(BADCy)=1∶1∶2、w(nano-SiO2)=3%时,相应BOZ/BMI/BADCy胶粘剂的表观活化能(47.82 kJ/mol)低于无nano-SiO2体系(59.17 kJ/mol),并具有良好的耐高温性能;在250℃时用该胶粘剂胶接硅钢片,胶接件经250℃老化1 000 h后,其剪切强度仍保持稳定。     

热塑性树脂改性氰酸酯树脂研究

采用热塑性树脂对双酚A型氰酸酯树脂（BADCy）进行增韧改性,根据改性BADCy的DSC曲线确定了改性BADCy的固化工艺。结果表明,热塑性树脂的加入对BADCy的固化行为影响较小,但能极大地提高BADCy的力学性能,当热塑性树脂质量分数为8％时,其弯曲强度和冲击强度分别从改性前的104．0MPa和6．0kJ／m^2提高到120．1MPa和14．2kJ／m^2,有效地增大了BADCy的韧性。     

Toughening modification of cyanate ester with amino-terminated polyoxypropylene

An amino-terminated polyoxypropylene (DA2000) was used to modify a bisphenol A-type cyanate ester resin (BADCy). A series of BADCy/DA2000 resins with different DA2000 contents were prepared and investigated by mechanical tests, dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The results of mechanical tests demonstrated that the addition of DA2000 improved the bending and tensile strength of the modified resins. Compared with those of pure BADCy, the K _IC and G _IC values of the modified resins increased, indicating an improvement in toughness of the resin system. The DMA curves of modified resins showed that the storage moduli dropped with the increase in temperature and the T _g values decreased with the increase in modifier content. Simultaneously, the moduli showed different changing trend at different temperature stages, indicating the existence of phase separation, which was also demonstrated by the fracture morphologies. At 20 wt% of DA2000 content, the fracture surface showed its characteristic strong ductile tear. Based on the above results, it was concluded that the –NH₂ groups of DA2000 reacted with the –OCN groups of triazine ring to form flexible segments, which were embedded into the main chains of the curing network; the distance between the triazine rings increased, the cross-link density decreased and the yield deformation of the system was enhanced. Meanwhile, DA2000 reacted with BADCy monomers to form linear macromolecular chains, which interpenetrated into the network matrix, and enhanced the plastic deformation of the system. The formation of flexible segments, low cross-link density and the yield and plastics properties led to toughened cyanate ester (CE) resins.     

Low‐temperature cure high‐performance cyanate ester resins/microencapsulated catalyst systems

The encapsulated catalyst can be released under stimulation conditions to control the polymerization reaction. In this study, poly(urea‐formaldehyde) (PUF) microcapsules (MCs) filled with dibutyltin dilaurate (DBTDL) catalyst (PUF/DBTDL MCs) were applied to bisphenol A dicyanate ester (BADCy) resins to develop a novel low temperature cure high performance BADCy/MCs systems. The effect of PUF/DBTDL MCs on the reactivity of BADCy was investigated. The mechanical property, the thermal property, the water uptake, and the dielectric property of cured BADCy/MCs resin systems were discussed in detail. Results indicate that roughly varying the content of the encapsulated DBTDL can easily and safely adjust the polymerization temperature. The BADCy systems with proper content of MCs cured at low temperature show excellent mechanical property, good thermal property, low water uptake, and low dielectric property. When the content of MCs is 0.125 wt%, the cured BADCy/MCs system has the optimal integrated properties owing to the formation of more uniform crosslinked structure and high conversion of cyanate ester (? OCN) groups resulting from the slow release of DBTDL catalyst through the wall shell under heating condition. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers     

氮化硼粒子增强氰酸酯树脂基复合材料的研究

在玻璃布增强氰酸酯树脂（CE）基复合材料中加入氮化硼(BN)粒子,制得CE/玻璃布/BN复合材料。研究了BN粒子含量对复合材料性能的影响。结果表明,经偶联剂处理的BN粒子使体系凝胶时间缩短,反应活性略有提高。BN粒子的加入可以明显提高复合材料的弯曲强度和层间剪切强度,在BN加入量为8 %时,复合材料的弯曲强度和层间剪切强度达到最大值,分别提高了5 %和36 %。加入BN粒子后,复合材料的起始热分解温度都较未填充体系有所提高,耐热指数升高,热稳定性相应提高。