核壳聚合物增韧环氧树脂的进展

核壳聚合物（CSP）现已用于增韧环境树脂，它具有许多优点：预先设计的CSP在环氧基体中的形态、大小和分散状态与固化规范无关；在提高环氧树脂韧性的同时不降低玻璃化温度。本文综述了CSP／环氧共混物的性能和增韧机理。主要的增韧机理是CSP粒子空穴化，释放裂缝附近的三轴度，继而产生膨胀形变和剪切屈服。     

核壳聚合物增韧环氧树脂的研究进展

核壳聚合物(CSP)用来增韧环氧树脂的最大优点,在于提高韧性的同时而不降低材料的玻璃化转变温度(Tg)和加工性能。综述了核壳聚合物增韧环氧树脂的特点,核壳聚合物的制备方法、微观结构及形态,以及增韧环氧树脂及其复合材料的性能及影响因素。     

有机硅核壳聚合物增韧环氧树脂胶黏剂

有机硅核壳聚合物(CSP)是一种以柔软而有弹性的交联有机硅(PDMS)为核、以聚甲基丙烯酸甲酯(PMMA)为壳的核壳聚合物,采用这种核壳聚合物增韧环氧基体树脂,采用FTIR、SEM、TGA和DSC对其化学结构、断面形貌和热性能进行了表征。结果表明,CSP添加量仅为10%即获得了最好的增韧效果,冲击强度达到了17.308 kJ/m²,比纯环氧树脂的冲击强度提高了95.3%,拉伸强度、剪切强度在CSP添加量为30%时分别达到了峰值4.58 MPa和28.44 MPa,相比于纯环氧树脂分别提高了275%和120%。     

有机硅核壳聚合物增韧环氧树脂胶黏剂

有机硅核壳聚合物(CSP)是一种以柔软而有弹性的交联有机硅(PDMS)为核、以聚甲基丙烯酸甲酯(PMMA)为壳的核壳聚合物,采用这种核壳聚合物增韧环氧基体树脂,采用FTIR、SEM、TGA和DSC对其化学结构、断面形貌和热性能进行了表征。结果表明,CSP添加量仅为10%即获得了最好的增韧效果,冲击强度达到了17.308 kJ/m~2,比纯环氧树脂的冲击强度提高了95.3%,拉伸强度、剪切强度在CSP添加量为30%时分别达到了峰值4.58 MPa和28.44 MPa,相比于纯环氧树脂分别提高了275%和120%。     

环氧树脂改性核壳乳胶粒子的制备

采用预乳化-半连续种子乳液聚合工艺制备了环氧树脂改性聚丙烯酸丁酯/(聚甲基丙烯酸甲酯-衣康酸)(PBA/P(MMA-ITA-DGEBA))核壳乳胶粒子。采用激光粒度仪、傅立叶变换红外光谱(FTIR)、差示扫描量热仪(DSC)、透射电子显微镜(TEM)等方法对核壳乳胶粒子进行了表征,实验结果表明:PBA/P(MMA-ITA-DGEBA)乳胶粒子确为核壳结构,双酚A型环氧树脂已经被成功接枝到核壳乳胶粒子上,由于ITA、DGEBA链段的存在,导致壳层PMMA玻璃化转变温度的(Tg)升高。     

丙烯酸酯核壳纳米粒子的合成及其改性环氧树脂

以丙烯酸丁酯(BA)为软单体、甲基丙烯酸甲酯(MMA)为硬单体和甲基丙烯酸缩水甘油脂(GMA)为官能单体,采用乳液聚合法合成出具有活性结构的BA/MMA/GMA核壳纳米粒子,并以此作为环氧树脂(EP)的增韧改性剂。研究结果表明:当w(核壳粒子)=10%、m(BA):m(MMA):m(GMA)=80:20:10时,与纯EP体系相比,改性EP体系的断裂伸长率提高了42.5%,剥高强度提高了近3倍,25℃和150℃时的剪切强度分别提高了48.6%和31.2%,坡璃化转变温度变化不大;红外光谱(FT-IR)证实,该核壳纳米粒子具有典型的特征吸收峰;透射电镜(TEM)观察结果表明,合成粒子具有纳米级核壳结构。     

核-壳弹性粒子改性E-44/DDM的研究

ＰＢＡ／ＰＭＭＡ型复合粒了能有效地降低环氧Ｅ－４／ＤＤＭ体系的内应力,提高力学性能。改性体系的分散相的尺寸由预制结构的复合粒子所控制。     

PB－PMMA核壳聚合物粒子的合

用负离子聚合技术合成出聚丁二烯,将其乳化成核,再用乳液聚合法与甲基丙烯酸甲酯接枝,合成了以聚丁二烯为核,聚甲基丙烯酸甲酯为壳的核-壳结构聚合物粒子。     

核壳聚硅氧烷弹性粒子的研究

综述了核壳聚硅氧烷弹性粒子的合成方法和不同因素对形成核壳聚硅氧烷粒子的影响。     

PB—PMMA核壳聚合物粒子的合成

用负离子聚合技术合成聚丁二烯,将其乳化成核,再用乳液聚合法与甲基丙烯酸甲酸接枝,合成了以聚丁二烯为核,聚甲基丙烯酸甲酯为壳的核－壳结构聚合物粒子。     

环氧树脂含量对氰酸酯热学性能的影响研究

采用示差扫描量热法(DSC)和热失重分析法(TGA)研究了环氧树脂含量对氰酸酯树脂固化反应特性、热稳定性以及热膨胀系数的影响。结果表明,环氧树脂的加入可有效降低改性体系的固化反应活化能,同时体系的热稳定性和尺寸稳定性有不同程度的削弱。当环氧树脂质量分数达到20%时,改性体系的表观活化能为65.4 kJ/mol,耐热温度指数为174℃,较纯氰酸酯树脂分别降低了25.8%和21.4%。当环氧树脂质量分数达到50%时,改性体系的热膨胀系数为65.3 922×10-6/℃(25～150℃),较纯氰酸酯树脂提高了8.13%。     

超支化聚合物在环氧树脂中的应用

综述了超支化聚合物在环氧树脂中的应用,简述了超支化环氧树脂、超支化环氧树脂固化剂和超支化环氧树脂添加剂的合成及应用进展,展望了其研究前景。     

核壳聚合物增韧环氧树脂的研究及进展

核壳聚合物(CSP)用来增韧环氧树脂的最大优点,即在提高韧性的同时而不降低材料的Tg和加工性能。综述了核壳聚合物增韧环氧树脂的特点,核壳聚合物的制备方法、微观结构及形态,以及增韧环氧树脂及其复合材料的性能及影响因素。树枝形聚合物作为一种结构特殊的聚合物,也越来越得到广泛的研究和应用。并对环氧树脂的增韧机理进行了阐述,即空穴化-塑性形变。文中还对核壳聚合物及树枝形聚合物增韧环氧树脂进行了展望。     

Thermal conductivity,elastic modulus,and coefficient of thermal expansion of polymer composites filled with ceramic particles for electronic packaging

The effective thermal conductivity, elastic modulus, and coefficient of thermal expansion of epoxy resins filled with ceramic fillers like silica, alumina, and aluminum nitride were determined. The data obtained was compared with theoretical and semitheoretical equations in the literature that are used to predict the properties of two phase mixtures. It was found that Agari's model provided a good estimate of the composite thermal conductivity. The Hashin‐Shtrikman lower bound for composite modulus fits the modulus data fairly well at low concentrations of the filler. Also, it was found that the coefficients of thermal expansion of the filled composites lie in between Schapery's upper and lower bounds. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3396–3403, 1999     

负热膨胀填料钨酸锆对环氧封装材料性能影响

由于封装材料与电子元件线膨胀系数差异大,成型后造成开裂、空洞和离层等缺陷,采用化学固相分步法制备的高纯度负热膨胀材料钨酸锆(ZrW2O8)颗粒作为填料,制备ZrW2O8/E-51及SiO2/E-51电子封装材料,测试了不同种类和含量的填料下封装材料线膨胀系数、显微硬度、玻璃化转变温度及磨损性能。实验结果表明:随ZrW2O8含量的增加,ZrW2O8/E-51材料线膨胀系数不断下降,显微硬度不断提高。ZrW2O8/E-51材料的磨损性能优于SiO2/E-51材料,磨损机理主要是粘着磨损和疲劳剥落,后期发生了磨粒磨损。     

Epoxy nanocomposites with reduced coefficient of thermal expansion

Control of the coefficient of thermal expansion (CTE) of polymeric materials is critical in many applications, particularly the electronics industry where CTE mismatches have caused failures. In theory, adding exfoliated nanoplatelets with high aspect ratios would offer an effective solution for reducing CTE, but reported results have not been compelling due to poor dispersion. In this study, α-zirconium phosphate (ZrP) nanoplatelets, along with organic surfactants, were added to epoxy thermosets. The CTE reduction and glass-transition temperature (T_g) were measured while the molecular weight of the surfactant was varied. High-molecular-weight surfactants are effective for ZrP exfoliation and dispersion, but they can also lead to a reduction in T_g and hinder the drop in CTE. A combination of two low-molecular-weight tetrabutylammonium hydroxide and 2-methoxyethylamine surfactants for exfoliation of ZrP were found to give a CTE reduction of 40% with just 3.5 vol % of ZrP added. This CTE reduction correlates well with theory. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47703.     

超支化聚合物改性环氧树脂的研究进展

超支化聚合物因其独特的结构和性能特点,已在众多领域得到了广泛的应用,尤其是在热固性树脂的改性中的应用,可作为热固性树脂的增韧剂。该文介绍了环氧树脂的性能特点及应用,超支化聚合物的结构及特点,着重论述了近年来超支化聚合物在改性环氧树脂力学性能、固化行为及热性能方面的研究进展,并指出了超支化聚合物在环氧树脂和其它热固性树脂改性方面的发展方向。     

Superiority of nanosized over microsized hyperbranched polymer second phase in modifying brittle epoxy resin

A hydroxyl‐functionalized hyperbranched polymer (HBP, H30) is used to modify 4,4′‐diaminodiphenylsulfone‐cured bisphenol‐A type epoxy resin and a separate phase structure of modified epoxy resins is observed. The effects of the H30 second phase size on the mechanical properties of modified epoxy systems are investigated systematically. The dependence of the toughening mechanisms on the HBP particle size is reported for the first time. It is shown that the nanosized H30 second phase is superior over microsized counterparts in modifying brittle epoxy resin. The tensile strength is slightly enhanced by the introduction of nanosized H30 second phase, whereas the strength is significantly reduced by the addition of microsized H30 phase. The failure strain and impact strength are obviously enhanced by the introduction of nanosized H30 second phase at low contents, whereas these properties are reduced by the addition of microsized H30 second phase at high contents. Finally, differential scanning calorimetric and thermogravimetric analyses are conducted to examine the effects of the HBP content on the glass transition temperature and the thermal stability, respectively. The glass transition temperature is slightly reduced while the thermal stability is not obviously influenced by the introduction of H30 second phase. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

有机硅改性双酚F环氧树脂热性能研究

以TMA和TGA研究了含酚羟基的有机烷氧基硅烷及3,3′,3″-三羟基苯氧基硅烷三缩水甘油醚等多种自行设计、合成的有机硅改性剂改性双酚F环氧树脂的热性能。研究结果表明,有机硅可降低改性树脂的线胀系数,但端环氧基脂肪族聚硅氧烷及含酚羟基的二官能度有机硅的加入均使固化物玻璃化温度降低10℃以上;含环氧基的多官能度有机硅改性剂3,3′,3″-三羟基苯氧基硅烷三缩水甘油醚的加入可使线胀系数降低约20%,内应力指数降低约20%,抗开裂指数提高50%以上,固化物玻璃化温度基本不变,热分解温度有较大幅度的提高,是一种理想的环氧树脂增韧改性剂,可用于电子封装等行业用环氧树脂的改性。     

环氧树脂基导热复合材料的研究进展

介绍了环氧树脂基导热复合材料的导热机理和导热模型,概述了国内外近年来在环氧树脂复合材料导热方面的研究开发和应用情况。