Si3N4/SiC/环氧树脂纳米导热复合材料的制备

以硅烷偶联剂KH-560改性的微米氮化硅/纳米碳化硅晶须(Si3N4/SiCw)为导热填料,浇注制备Si3N4/SiC/环氧树脂纳米导热复合材料.研究了环氧树脂种类、Si3N4/SiCw用量、复配比及表面改性对环氧树脂导热、力学和介电性能的影响.结果表明,环氧树脂的热导率随Si3N4/SiCw用量的增加而增大,当改性Si3N4/SiCw用量为50％[m(Si3N4) /m(SiCw)]=3/1时,环氧树脂的热导率为0.98 W/(m· K);复合材料的介电常数随Si3N4/SiCw用量的增加而增大,而力学性能则先增加后降低.     

Si3N4／环氧树脂导热复合材料制备和性能研究

采用硅烷偶联剂KH-550对氮化硅（β—Si3N4）进行表面处理,浇注制备氮化硅／环氧树脂（Si3N4／EP-828）复合材料,研究了Si3N4粒径、用量和表面改性对复合材料导热性能和力学性能的影响。结果表明,Si3N4／EP-828的导热性能随Si3N4用量的增加而提高,当Si3N4体积分数为30％时,热导率为0．83W／mK,为纯环氧树脂4倍多;力学性能则随Si3N4用量的增加先增大后降低。表面改性有助于进一步提高复合材料的导热性能和力学性能。初步分析表明,Si3N4／EP-828热导率与Si3N4形成的导热网链和Si-O-Si键导热骨架有关。     

耐高温高导热环氧树脂／玻纤／BN复合材料的制备

以4,4-二氨基二苯砜（DDS）和内亚甲基四氢邻苯二甲酸酐（NA）为复配固化剂,采用高温模压成型法制备耐高温高导热环氧树脂／玻纤／氮化硼（BN）复合材料。探讨了BN用量和偶联剂处理对复合材料冲击强度、导热性能和电阻率的影响。结果表明：当nDDS：nNA=3：1时,复合材料的耐热性能最佳。当BN质量分数为8％时,复合材料的冲击强度最高;导热性能随BN用量的增加而增加,当BN用量为15％时,热导率为0．7560W／（mk）,此时复合材料仍保持较高的体积、表面电阻率;当BN填充量为一定值时,偶联剂处理使冲击强度和导热性能得到进一步提高。     

高导热高绝缘FEP／AIN复合材料的研究

采用聚全氟乙丙烯（FEP）为基体，偶联处理的氮化铝（AIN）为填料，通过共混、模压等方法制备了高导热、高绝缘的FEP／AIN复合材料。结合材料导热计算模型，分析了AIN用量对材料热导率、体积电阻率、力学以及流变性能的影响。结果表明：随AIN填充量的增加，复合材料的热导率呈近线性增加，当AIN的质量分数为30％时，材料的热导率可达2．22W／m·K），体积电阻率可达1．5×10^15Ω·cm，并具有较好的力学性能和流变性能。     

BN／Al2O3／环氧树脂导热复合材料的制备与性能

分别采用氮化硼（BN）、氧化铝（Al2O3）和复配BN／Al2O3作为导热填料制备环氧树脂导热复合材料。结果表明,环氧树脂热导率随导热填料用量的增加而增大;同等用量下,BN／Al2O3／环氧树脂复合材料的导热性能均优于BN／环氧树脂和Al2O3／环氧树脂。当BN／Al2O3质量分4~50％[m（BN）／m（Al2O3）=3／1J,复合材料热导率为08194W／mK。此外,随BN／Al2O3用量的增加,环氧树脂的介电常数和介电损耗角正切增加,而弯曲强度和冲击强度则先增加后降低。     

碳化硅晶须/碳化硅颗粒/聚丙烯复合材料的结构优化设计和模型拟合

以聚丙烯(PP)为基体,以单一碳化硅晶须( SiCw)、碳化硅颗粒(SiCp)和混杂SiCw/SiCp为导热填料,共混/模压制备PP基导热复合材料.结果表明:同等用量下,混杂SiCw/SiCp填充PP具有比单一SiCw或SiCp填充PP更佳的导热性能,且随SiCw/SiCp用量的增加而增加;当SiCw/SiCp质量分数为50％时,导热性能最佳,其导热系数为0.856 W/(m· K),为纯PP的5倍多.PP的拉伸强度与冲击强度随SiCw/SiCp用量的增加先增加后降低,当混杂SiCw/SiCp质量分数为10％时,力学性能最佳.相比SiCp而言,SiCw更易在PP中形成导热网链.     

热塑性聚酰亚胺复合材料导热性能研究

采用稳态热板法测定铜粉（Cu）填充热塑性聚酰亚胺（TPI）复合材料的热导率，研究了Cu填充量对复合材料的力学性能和导热性能的影响，初步探讨了温度与复合材料热导率的关系。通过扫描电子显微镜观察了复合材料的微观形态。在此基础上，理论计算复合材料热导率。研究表明，Cu填充TPI可有效提高复合材料力学性能和导热性能。当Cu体积分数提高到26％时，填料聚集形成导热链，Cu／TPI复合材料的热导率是纯TPI树脂的3．5倍；当填料含量低于10％时，Maxwell—Eucken模型适合预测复合材料热导率；基于导热链考虑的Y．Agan模型可较好地反映复合材料热导率随填料含量的变化情况；随着温度的升高，Cu／TPI复合材料热导率先增大后趋于平缓。     

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。     

氮化硅/碳纤维/环氧树脂复合材料的制备研究

采用高温模压成型法制备氮化硅/碳纤维/环氧树脂导热复合材料(SiN/CF/EP)。研究了34SiN用量和表面改性对SiN/CF/EP复合材料导热性能、导电性能和力学性能的影响。结果表明,复合材料3434的导热性能随SiN质量分数的增加而增大,当SiN质量分数为40%时,导热率为1.02W/mK;而3434SiN/CF/EP复合材料的导电率随SiN质量分数的增加而呈线性降低;力学性能则随SiN质量分数的增加先343434增大后降低。表面改性有助于进一步提高SiN/CF/EP复合材料的导热性能和力学性能。34     

聚偏氟乙烯/鳞片石墨/碳纤维高导热复合材料的制备

以聚偏氟乙烯（PVDF）树脂为基体,天然鳞片石墨（FG）、碳纤维（CF）为填料,采用熔融共混法制备了PVDF/FG/CF复合导热材料,并研究了FG、CF含量及其改性对复合材料导热性能和力学性能的影响。结果表明,复合材料的热导率随FG含量的增加而增大,力学性能随着FG含量的增加而降低;CF的加入提高了复合材料的力学性能,但热导率略有降低;对CF进行表面氧化处理将使得复合材料的热导率以及力学性能有所提高,当CF含量为5 %、FG含量为50 %时,复合材料的热导率为11.4 W/(m·K),拉伸强度为48 MPa,断裂伸长率为11 %。     

Preparation and properties of epoxy/BN highly thermal conductive composites reinforced with SiC whisker

A simple method is reported to increase the thermal conductivity and improve the poor mechanical properties caused by high filler loadings of epoxy composites, simultaneously. Epoxy composites were prepared with micro‐boron nitride (BN) and silicon carbon whisker (SiCw) chemically treated by 3‐aminopropyltriethoxysilane (KH550) and 3‐glycidyloxypropyltrimethoxysilane (KH560), respectively. Effects of surface modification of BN particles on the thermal conductivity and flexural strength of epoxy/BN composites were investigated. About 3% SiCw particles grafted with KH560 were incorporated into composites with BN grafted with KH550, which led to about 13.8–17.8% increase of the flexural strength as well as a marginal improvement of the thermal conductivity of composites, and they possessed good dielectric properties. In addition, dynamic mechanical analysis results showed that the storage modulus of composites increased significantly with the addition of fillers, while the glass transition temperature exhibited a slight decrease. POLYM. COMPOS., 37:2611–2621, 2016. © 2015 Society of Plastics Engineers     

Preparation and properties of polystyrene/SiCw/SiCp thermal conductivity composites

The silicon carbide whisker (SiCw) and silicon carbide particle (SiCp) were employed to prepare polystyrene/silicon carbide whisker/silicon carbide particle (PS/SiCw/SiCp) thermal conductivity composites, and the titanate coupling reagent of NDZ‐105 was introduced to functionalize the surface of fillers. The thermal conductive coefficient λ improved from 0.18 W/mK for native PS to 1.29 W/mK for the composites with 40% volume fraction of SiCw/SiCp (volume fraction, 3 : 1) hybrid fillers. Both the thermal decomposition temperature and dielectric constant of the composites increased with the addition of SiCw/SiCp hybrid fillers. At the same addition of SiCw/SiCp hybrid fillers, the surface modification of hybrid fillers by NDZ‐105 could improve the thermal conductivity and the mechanical properties of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

某高导热纤维及其复合材料性能研究

研究了某高导热纤维/环氧树脂单向层复合材料的导热系数和力学性能,发现某高导热纤维/环氧树脂单向层复合材料导热性能提高的同时其个别复合材料性能降低;分析认为某高导热纤维与环氧树脂的界面性能是影响复合材料力学性能的重要因素,同时研究了某高导热纤维的表面微观形貌和表面化学特性、结晶度及某高导热纤维/环氧树脂浸胶丝束的力学性能...     

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。     

PA6/BN/MgO导热复合材料的制备与性能研究

以聚酰胺6（PA6)为基体,以氮化硼（BN）、氧化镁（MgO）为导热填料制备了PA6/BN/MgO导热复合材料。固定填料含量为50%（质量分数,下同）不变,考察MgO/BN配比的变化对复合材料热导率、力学性能和熔体流动性的影响。结果表明,材料的热导率、拉伸强度和弯曲强度随着MgO/BN配比的增大而减小,冲击强度和断裂伸长率随着MgO/BN配比的增大而增大,材料熔体流动性则呈现了随MgO/BN配比的增大先增大后减小的趋势。     

Studies on Preparation and Property Researches of EP/SiC Thermal Conductivity Composites

The epoxy resin/silicon carbide thermal conductivity composites were prepared via casting method. The content of SiC and coupling reagents effecting on the thermal conductivity, mechanical and thermal properties of composites were investigated. Results revealed that the thermal conductivity properties of the composites were improved with the increasing mass fraction of SiC, and the thermal conductivity coefficient λ was 0.7152 W/mk with 50% mass fraction of SiC, being over 3 times of that of native epoxy resin. The flexural strength and impact strength of the EP/SiC composites increased firstly, but decreased with excessive addition of SiC, and the properties of EP/SiC composites were maximum with 10 wt% SiC. DSC and TGA analysis showed that the glass transition temperature (Tg) of composites decreased, but the heat resistance increased with the addition of SiC. SEM observation of impact fracture revealed that the impact strength had the relationships of large or small fracturing ability and the fracturing extended ability and the resin elasticity deformation.     

短切/连续碳纤维协同增强本征导热环氧树脂基复合材料研究

采用含有联苯介晶基元结构的3,3’,5,5’-四甲基联苯二酚二缩水甘油醚（TMBP）与含有芳香酰胺介晶基元结构的固化剂4,4-二氨基苯酰替苯胺（DABA）制备本征导热TMBP/DABA环氧树脂。结果表明,热导率高达0.33 W/（m·K）,比普通双酚A缩水甘油醚（DGEBA）/4,4’-二氨基二苯甲烷（DDM）环氧树脂的热导率高约50%,相应短切碳纤维（含量为75%,质量分数,下同）增强复合材料面外和面内热导率分别高约42.7%和40.2%。采用紫外臭氧氧化方法对短切碳纤维（SCF）和连续碳纤维（M55J）进行表面改性,发现能够明显改善纤维与基体树脂之间的界面结合强度,进而提高复合材料的导热性能。进一步采用SCF和M55J为增强纤维、本征导热TMBP/DABA环氧树脂为基体树脂制备出短切/连续碳纤维协同增强本征导热环氧树脂基复合材料SCF/M55J/TMBP/BADA。SCF的加入能够同时改善M55J/TMBP/DABA单向复合材料板沿X、Y、Z轴方向的热导率,分别最高达到98.07、48.23、9.40 W/（m·K）。为改善复合材料综合导热性能提供了一种新思路。     

纳米氧化铝/天然橡胶复合材料的性能研究

采用原位改性纳米氧化铝制备纳米氧化铝/天然橡胶(NR)复合材料,研究纳米氧化铝用量及原位改性时间、偶联剂Si69用量对纳米氧化铝/NR复合材料的物理性能、动态力学性能和导热性能的影响。结果表明:随着纳米氧化铝用量的增大,复合材料的拉伸强度减小,热导率和压缩疲劳温升增大。原位改性可以提高纳米氧化铝与NR之间的界面结合作用。随着原位改性时间的延长或随着偶联剂Si69用量的增大,复合材料的拉伸强度和热导率均先增大后减小,压缩疲劳温升逐渐减小。     

PP/PCL/石墨/碳纳米管复合材料的制备及电性能分析

采用熔融共混法制备了石墨（G）、碳纳米管（CNTs）与聚丙烯（PP）、聚己内酯（PCL）导电复合材料,通过改变G的添加量制备了系列导电复合材料。主要测试了熔体流动速率、力学性能、导电性能、电热性能,并进行了电子显微镜观察结构、差示扫描量热法分析、热失重分析。结果表明,PCL与PP混合后,PP的拉伸强度提升了4.375 MPa,在加入G/CNTs之后,力学性能受影响较大下降了约73.5 %;G/CNTs的加入还能有效降低PP的电阻率,使其从绝缘体变为半导体材料电阻率为7.83×10⁶ Ω·m;PP与PCL共混后复合材料的热稳定性得到了显著提高,初始分解温度从368.88 ℃升高至398.95 ℃,在加入G/CNTs管后又进一步提高至408.78 ℃。     

Preparation of β‐SiCw/BDM/DBA composites with excellent comprehensive properties

Functionalized β‐SiC whiskers (β‐SiCw) are employed to prepare β‐SiCw/N,N′‐4, 4′‐bimaleimide diphenyl methane/diallylbisphenol A (β‐SiCw/BDM/DBA) composites via powder blending‐casting method. The thermal conductive coefficient of the β‐SiCw/BDM/DBA composites is 0.994 W/mK with 40 wt% functionalized β‐SiCw, five times higher than that of pure BDM/DBA. The mechanical properties of the β‐SiCw/BDM/DBA composites are optimal with 10 wt% functionalized β‐SiCw. Both thermal resistance and dielectric constant are increased with the increasing addition of β‐SiCw. For a given β‐SiCw loading, the surface functionalization of β‐SiCw exhibits a positive effect on the thermal conductivities and mechanical properties of the β‐SiCw/BDM/DBA composites. POLYM. COMPOS., 35:1875–1878, 2014. © 2014 Society of Plastics Engineers