环氧树脂／碳化硅晶须导热复合材料的制备研究

用共混复合-浇注成型法制备环氧树脂／碳化硅晶须（EP／SiCw）导热复合材料,研究了导热填料种类、形状、用量和表面处理对复合材料的导热性能、力学性能和热性能的影响。结果表明,SiCw较SiCp更易改善材料的导热性能,热导率随SiCw用量的增加而增大,当SiCw体积分数为42．1％时,复合材料热导率为0．9611W／（m·K）;力学性能随SiCw用量的增加先增加后降低。表面处理有利于提高复合材料的导热性能和力学性能。SiCw的加入使环氧树脂的耐热性提高、Tg降低。     

Effect of nanoparticles on the performance of thermally conductive epoxy adhesives

Microsized or nanosized α‐alumina (Al₂O₃) and boron nitride (BN) were effectively treated by silanes or diisocyanate, and then filled into the epoxy to prepare thermally conductive adhesives. The effects of surface modification and particle size on the performance of thermally conductive epoxy adhesives were investigated. It was revealed that epoxy adhesives filled with nanosized particles performed higher thermal conductivity, electrical insulation, and mechanical strength than those filled with microsized ones. It was also indicated that surface modification of the particles was beneficial for improving thermal conductivity of the epoxy composites, which was due to the decrease of thermal contact resistance of the filler‐matrix through the improvement of the interface between filler and matrix by surface treatment. A synergic effect was found when epoxy adhesives were filled with combination of Al₂O₃ nanoparticles and microsized BN platelets, that is, the thermal conductivity was higher than that of any sole particles filled epoxy composites at a constant loading content. The heat conductive mechanism was proposed that conductive networks easily formed among nano‐Al₂O₃ particles and micro‐BN platelets and the thermal resistance decreased due to the contact between the nano‐Al₂O₃ and BN, which resulted in improving the thermal conductivity. POLYM. ENG. SCI., 50:1809–1819, 2010. © 2010 Society of Plastics Engineers     

BN/环氧树脂导热灌封胶的制备与性能

采用硅烷偶联剂KH-560对氮化硼(BN)进行表面处理,用于制备BN/环氧树脂导热灌封胶。结果表明,随着BN用量的增加,环氧导热灌封胶的剪切强度下降,导热性能则增加,表面改性有助于提高环氧灌封胶的剪切强度和导热性能。CTBN的加入可有效提高剪切强度。当改性BN和CTBN质量分数均为15%时,BN/环氧灌封胶具有较理想的剪切强度、热性能和导热性能。     

环氧树脂/石英纤维透波复合材料制备

为改善环氧树脂的介电性能及提升石英纤维的界面性能,使用缩水甘油醚基笼型倍半硅氧烷(G-POSS)和γ-氨丙基三乙氧基硅烷(KH-550)分别对环氧树脂和石英纤维进行改性.利用差示扫描量热法研究改性后环氧树脂的固化过程,并通过外推法确定了其固化工艺,根据固化工艺制备环氧树脂/石英纤维复合材料,分别对该复合材料的热稳定性、...     

Preparation and properties of multi‐walled carbon nanotubes/carbon fiber/epoxy composites

Multi‐walled carbon nanotubes/carbon fiber (MWCNTs/CF) hybrid fillers are employed to prepare MWCNTs/CF/epoxy composites. Results reveal that a great improvement of the thermal conductivities of the epoxy composites with the addition of MWCNTs/CF hybrid fillers, and the thermal conductivity of the MWCNTs/CF/epoxy composites is 1.426 W/mK with 8 vol% treated MWCNTs/CF hybrid fillers (5 vol% MWCNTs + 3 vol% CF). Both the flexural and impact strength of the MWCNTs/CF/epoxy composites are increased firstly, but decreased with the excessive addition of MWCNTs. The flexural and impact strength of the MWCNTs/epoxy composites are optimal with 2 vol% MWCNTs. For a given MWCNTs/CF hybrid fillers loading, the surface treatment of MWCNTs/CF hybrid fillers can further increase the thermal conductivities and mechanical properties of the MWCNTs/CF/epoxy composites. POLYM. COMPOS., 35:2150–2153, 2014. © 2014 Society of Plastics Engineers     

High thermal conductive m‐xylylenediamine functionalized multiwall carbon nanotubes/epoxy resin composites

In this study, multiwall carbon nanotubes (MWNTs) functionalized by m‐xylylenediamine is used as thermal conductive fillers to improve their dispersibility in epoxy resin and the thermal conductivity of the MWNTs/bisphenol‐A glycidol ether epoxy resin composites. Functionalization with amine groups of MWNTs is achieved after such steps as carboxylation, acylation and amidation. The thermal conductivity, impact strength, flexural strength, and fracture surfaces of MWNTs/epoxy composites are investigated with different MWNTs. The results show that m‐xylylenediamine is successfully grafted onto the surface of the MWNTs and the mass fraction of the organic molecules grafted onto MWNTs is about 20 wt %. The thermal conductivity of MWNTs/epoxy composites is further enhanced to 1.236 W/mK with 2 wt % m‐MWNTs. When the content of m‐MWNTs is 1.5 wt %, the impact strength and flexural strength of the composites are 25.85 KJ/m², 128.1 MPa, respectively. Scanning electron microscope (SEM) results show that the fracture pattern of composites is changed from brittle fracture to ductile fracture. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41255.     

环氧树脂/玻纤/BN导热绝缘复合材料制备研究

采用高温模压成型法制备环氧树脂/玻纤/BN导热复合材料,探讨了BN用量对复合材料力学性能、导热性能和电性能的影响,结果表明.当BN用量为10%时,复合材料的冲击强度和弯曲强度较佳;导热性能随BN用量的增加而提高,当BN用量为20%耐.热导率为0.7438 W/mk,此时复合材料仍保持较好的绝缘性能.     

影响中空玻璃微珠填充PS复合材料性能的因素

研究了中空玻璃微珠的表面改性和粒径分布,苯乙烯-丁二烯-苯乙烯弹性体(SBS)的加入对聚苯乙烯(PS)/中空玻璃微珠复合材料力学性能的影响.结果表明:硅烷偶联剂KH550对中空玻璃微珠的表面改性效果优于KH560;粒径分布窄的中空玻璃微珠填充PS复合材料具有较高的拉伸强度、弯曲强度和冲击强度:SBS的加入可以提高复合材料的力学性能,尤其可以大幅提高简支梁缺口冲击强度.     

稻壳二氧化硅/环氧树脂纳米复合材料机械性能研究

将稻壳用10%的盐酸处理后在600℃焚烧得到纯度为99.3%的SiO_2,将SiO_2用偶联剂γ-氨丙基三乙氧基硅烷(KH550)改性后与环氧树脂(EP)复合,探讨了SiO_2质量分数在0～5%范围内复合材料的力学性能.研究结果显示:经硅烷偶联剂KH550改性后稻壳SiO_2粒子为无定形态,尺寸在30～50 nm且能显著提高环氧树脂的力学性能.当稻壳SiO_2质量分数为3%时,材料的拉伸性能以及弯曲性能的提高率最大,拉伸强度、拉伸模量、弯曲模量和弯曲强度的提高率分别为27.25%、6.54%、61.7%和24.56%.SEM研究结果显示:复合材料中SiO_2与基体树脂之间有较好的相容性.     

环氧树脂/碳纤维/BN导热复合材料制备及研究

采用高温模压成型法制备环氧树脂/碳纤/BN导热复合材料.探讨了BN用量对复合材料导热性能和力学性能的影响.结果表明,当BN用量为6%(wt)时,复合材料的弯曲强度和剪切强度较佳,BN用量对复合材料的冲击强度影响不大;导热性能随BN用量的增加而增加,当BN用量为20%(wt)时,导热系数为0.8438W/m·K.     

SiO2气凝胶纤维隔热复合材料的常压制备及性能表征

SiO₂气凝胶的力学性能较差,隔热性能较强,为了使其成为良好的隔热材料,本文提出一种SiO₂气凝胶纤维隔热复合材料的制备方法。以正硅酸乙酯(TEOS)为前驱体,玻璃纤维和陶瓷纤维为增强体,硅烷偶联剂KH550和KH570为纤维处理剂,在常压条件下制备SiO₂气凝胶纤维隔热复合材料,并对材料性能进行表征。结果表明:前驱体中十六烷基三甲基溴化铵(CTAB)含量越高,复合材料中SiO₂气凝胶导热系数越低,低至0.028 W/(m·K);使用硅烷偶联剂KH550时,基体和纤维之间结合的紧密程度更高;纤维的加入使SiO₂气凝胶的力学性能达到很高水平;当前驱体中TEOS与CTAB摩尔比为1∶0.022时,经KH550处理的玻璃纤维/SiO₂气凝胶复合材料导热系数为0.054 W/(m·K),力学性能良好,隔热性能最优。     

偶联剂对nano-ZnO/HDPE复合材料性能的影响

通过熔融共混法制备出不同硅烷偶联剂(KH550,KH560)改性的nano-ZnO/HDPE复合材料,并考察了偶联剂及ZnO含量对复合材料性能的影响。结果表明:改性nano-ZnO对HDPE基体起到了明显的增强增韧的效果,当改性nano-ZnO含量为0.2%～0.5%时,复合材料的力学性能最好。此外,nano-ZnO在HDPE中起异相成核剂的作用,从而使体系的熔融温度、结晶温度和结晶度升高。经KH560处理的nano-ZnO/HDPE复合材料的力学性能和结晶性能均优于经KH550处理的nano-ZnO/HDPE复合材料的性能。     

Thermal and mechanical properties of epoxy composites reinforced by a natural hydrophobic sand

If a low weight percentage of crude fine fillers can improve properties of polymer materials directly without complicated chemical treatment process involved, it will be significant for many industrial applications. Our previous study indicated that a kind of Cancun natural sand could be an effective filler material for polymer composites. In this current work, the epoxy composites reinforced by this kind of natural sand particles were prepared and thermal and mechanical properties of the composites containing up to 5 wt % of the sand particles were characterized. Results showed that the highest flexural strength appears in the epoxy composite containing 1 wt % sand particles. A damage model was used to interpret the flexural properties, which showed an acceptable agreement with the experimental results. The glass transition temperature, high temperature storage modulus, and dimensional stability of the sand/epoxy composites monotonically increased with the addition of the sand particles. The sand particle/epoxy composites also displayed a noticeable enhancement in thermal conductivity. Theoretical analysis showed that in addition to conduction, other heat transport mechanisms played roles in the improved heat transmission through the composites. As a natural porous micron-scale material, Cancun sand has the potential for applications in cost-effective composites with enhanced mechanical and thermal properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

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。     

环氧树脂/玻璃布/BN导热复合材料的制备与性能研究

采用高温模压成型法制备环氧树脂(EP)/玻璃布/氮化硼(BN)导热复合材料。探讨了BN用量和偶联剂处理对复合材料力学性能、导热性能和介电性能等影响。结果表明:当w(BN)=15%时,复合材料的冲击强度较高;导热性能随着BN用量的增加而增大;当w(BN)=25%时,改性复合材料的热导率为0.901 2 W/(m.K),此时复合材料仍保持较低的介电常数和介电损耗。当BN用量相同时,偶联剂表面处理可有效改善复合材料的力学性能和导热性能。     

热致性液晶聚合物/酚醛树脂/氧化石墨烯混杂复合材料的性能研究

采用熔融挤出法将热致性液晶聚合物(TLCP)与酚醛树脂(PF)熔融挤出,分别加入改良Hummers法制备的氧化石墨烯(GO)、硅烷偶联剂改性GO(KH550 GO、KH560 GO),制备了TLCP/PF/GO混杂复合材料,研究了加入GO对TLCP/PF/GO混杂复合材料的力学性能、摩擦磨损性能的影响。结果表明,硅烷偶联剂处理的GO能一定程度提高复合材料的摩擦磨损性能和力学性能,特别是TLCP/PF/KH560 GO混杂复合材料的摩擦因数稳定,在150 ℃和250 ℃下的体积磨损率分别降低了20.6 %和23.1 %,材料的冲击强度提高了18.6 %。     

Liquid crystal epoxy composites based on functionalized boron nitride: Synthesis and thermal properties

A composite was prepared by in-situ polymerization of liquid crystal epoxy (LCE₄) with a low dielectric and high thermal conductivity boron nitride (BN) filler, which the filler (f-BN) was surface-functionalized by γ-glycidoxypropyltrimethoxysilane (KH560) and aminopropylisobutyl polyhedral oligomeric silsesquioxane (NH₂-POSS). The surface-functionalized BN was more uniformly dispersed in LCE₄, which improved the interfacial compatibility between inorganic and organic phases. Compared with pure LCE₄, KH560, and NH₂-POSS modified f-BN/LCE₄ composites exhibited a higher glass transition temperature, better thermal stability, and higher thermal conductivity. For example, when the f-BN content reached 30 wt%, the energy storage modulus of the composite increased to 2580 MPa, and the glass transition temperature was 103°C. The thermal conductivity of this 30 wt% f-BN composite was 0.48 W m⁻¹ K⁻¹, 128.6% higher than that of pure LCE₄. In addition, thermal stability, low hygroscopicity, and dielectric properties of the composites were characterized and analyzed to explore the application prospects of f-BN/LCE₄ composites in electronic packaging and in high-performance microelectronic devices.     

环氧树脂/氧化锌晶须/氮化硼导热绝缘复合材料的研究

以环氧树(脂EP)为基体,分别以氧化锌晶(须ZnOw)和ZnOw/氮化硼(BN)混合物为导热填料,制备了EP导热绝缘复合材料。研究了填料含量对复合材料导热性能、电绝缘性能及力学性能的影响,并利用扫描电镜对复合材料的断面形貌进行了观察。结果表明:随着导热填料含量的增大,复合材料的导热系数和介电常数增大,体积电阻率下降,而拉伸强度呈先增大后减小的趋势;在填料含量相同的情况下,EP/ZnOw/BN复合材料比EP/ZnOw复合材料具有更好的导热性能;当填料体积分数为15%时,EP/ZnOw/BN复合材料的热导率为1.06W/(mK)而,EP/ZnOw复合材料的热导率仅为0.98W/(mK)。     

Fabrication of thermally conductive composite with surface modified boron nitride by epoxy wetting method

Boron nitride (BN) particles fabricated with different surface treatments were used to prepare thermally conductive polymer composites by epoxy wetting. The polar functionality present on the BN particles allowed the permeation of the epoxy resin because of a secondary interaction, which allowed the fabrication of a composite containing high filler concentration. The different cohesive energy densities of the synthesized material due to a functional-group-induced surface treatment effect on surface free energy and wettability determined the thermal and mechanical properties of the polymer. The results indicate that surface-curing agents interrupt the interaction between the filler and matrix, and do not always enhance thermal conductivity. Moreover, the composites showed maximum thermal conductivity at 30 wt% epoxy loading when the fixed-pore volume fraction reached in the filtrated BN film. The measured storage modulus was also enhanced by surface treatment because of the sufficient interface produced and interaction between the large amount of the filler and epoxy.     

New composites with high thermal conductivity and low dielectric constant for microelectronic packaging

Three composites based on cyanate (CE) resin, aluminum nitride (AlN), surface‐treated aluminum nitride [AlN(KH560)], and silicon dioxide (SiO₂) for microelectronic packaging, coded as AlN/CE, AlN(KH560)‐SiO₂(KH560)/CE, and AlN‐SiO₂/CE composite, respectively, were developed for the first time. The thermal conductivity and dielectric constant of all composites were investigated in detail. Results show that properties of fillers in composites have great influence on the thermal conductivity and dielectric constant of composites. Surface treatment of fillers is beneficial to increase the thermal conductivity or reduce dielectric constant of the composites. Comparing with binary composite, when the filler content is high, ternary composites possess lower thermal conductivity and dielectric constant. The reasons leading to these outcomes are discussed intensively. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers