中温固化环氧复合材料的颗粒增韧技术

介绍了几种复合材料的颗粒增韧方法,通过分析比较选择了热塑性树脂颗粒层间增韧和基体增韧的方法对中温固化环氧树脂进行改进,着重研究了增韧剂用量对增韧效果的影响。     

纳米CaCO_3高填充ABS复合材料的制备

分别采用苯乙烯-丁二烯-苯乙烯共聚物(SBS)和乙烯-乙酸乙烯共聚物(EVA)作增韧剂,利用熔融挤出法制备纳米CaCO_3高填充丙烯腈-丁二烯-苯乙烯三元共聚物(ABS)/CaCO_3复合材料,研究了纳米CaCO_3填充量和增韧剂种类对ABS/CaCO_3复合材料力学性能和熔体流动速率的影响。结果表明:SBS对ABS/CaCO_3复合材料的增韧效果优于EVA;当ABS用量为100.0 phr、纳米CaCO_3填充量为25.0 phr、SBS用量为5.0 phr时,可得到力学性能符合GB/T 10009—1988要求的ABS/CaCO_3复合材料;当SBS和EVA用量较低时,SBS更能明显提高ABS/CaCO_3复合材料的熔体流动速率。     

矿用电器外壳材料改性ABS的研制

以丙烯腈-苯乙烯-丁二烯共聚物(ABS)为基体材料,加入阻燃剂(溴-锑阻燃体系)、抗静电剂、增韧剂制备了矿用电器外壳材料。考察了不同阻燃剂、抗静电剂、增韧剂对ABS性能的影响。结果表明:选用优化配方的阻燃抗静电ABS复合体系具有良好的阻燃和抗静电性能;分别采用SBS、ABS髙胶粉、MBS对阻燃抗静电ABS进行增韧,ABS髙胶粉增韧效果最好,当其质量分数为15%时,制品在-25℃、冲能7J时不损坏、无裂纹,而且对材料阻燃性未造成影响;利用该改性ABS材料制备的电器外壳各项性能均能满足矿用标准要求。     

环氧/酸酐固化体系耐湿性研究

对酸酐固化EP(环氧树脂)体系、加入增韧剂后的增韧体系进行了耐湿性研究,对增韧体系基体制作的玻璃纤维增强复合材料进行了水煮后性能试验。研究结果表明:EP/酸酐体系和增韧体系都具有优良的耐湿性,吸水率低于1%;水煮24 h后的复合材料也具有优良的耐水煮性,常温弯曲性能和剪切强度保持率均在90%以上。     

溴代三嗪/十溴二苯乙烷及CPE对ABS的增韧阻燃

以十溴二苯乙烷(DBDPE)与溴代三嗪(FR-245)为阻燃剂、三氧化二锑(Sb_2O_3)为协效剂、氯化聚乙烯(CPE)为增韧剂,对丙烯腈-丁二烯-苯乙烯共聚物(ABS)进行增韧阻燃,研究了阻燃剂与增韧剂对ABS力学性能及阻燃性能的影响。通过物理共混的方式制备了阻燃ABS复合材料,结果表明,FR-245/DBDPE质量比为3∶2,阻燃剂总质量分数为13%、CPE质量分数为8%时,增韧阻燃ABS复合材料综合性能优异,其垂直燃烧测试达到V-0级别,LOI值达到28%,拉伸强度为30.8MPa,缺口冲击强度为12.1kJ/m~2。     

微晶纤维素增强聚丙烯复合材料的制备与力学性能研究

以聚丙烯(PP)为基体、微晶纤维素(MCC)为增强材料、马来酸酐接枝聚丙烯(PP-g-MA)为相容剂,利用双螺杆挤出机制备了PP/MCC/PP-g-MA复合材料,同时研究了该复合材料的力学性能。随后分别选用三元乙丙橡胶(EPDM)和乙烯-辛烯共聚物(POE)对PP/MCC/PP-g-MA复合材料进行增韧改性,考察了两种增韧剂的增韧效果。结果表明:加入PP-g-MA后,PP/MCC复合材料的力学性能明显提高。另外,增韧剂的引入使PP/MCC/PP-g-MA复合材料的冲击性能显著改善,其中POE对复合材料的增韧效果优于EPDM。但是增韧剂的引入会造成复合材料的拉伸强度、弹性模量和弯曲强度分别出现不同程度的下降,其中EPDM增韧复合材料的上述性能下降幅度相对较小。     

阻燃ABS的增韧研究

分别以苯乙烯-丁二烯-苯乙烯共聚物(SBS)、乙烯-1-辛烯共聚物(POE)、三元乙丙橡胶(EPDM)为增韧剂,研究了它们对阻燃丙烯腈-丁二烯-苯乙烯共聚物(ABS)复合材料力学性能和阻燃性能的影响。结果表明:以SBS为增韧剂所得复合材料的综合性能优于以POE或EPDM为增韧剂所得复合材料;随SBS用量的增大,复合材料的冲击强度提高,当SBS用量为15%时,其冲击强度达到15.91kJ/m2,较未经增韧改性复合材料的冲击强度提高了9.99kJ/m2;并且SBS的加入不会对复合材料的阻燃性能产生不利影响。     

树脂基体中热塑性树脂含量对碳纤维环氧复合材料压缩性能的影响

制备了国产CCF800H碳纤维增强环氧树脂基复合材料,通过调控环氧树脂中的热塑性树脂增韧剂含量,探索增韧剂含量对树脂浇注体拉伸弹性模量的影响规律,并进一步研究增韧剂含量对碳纤维增强环氧树脂基复合材料纵向压缩性能的影响。结果表明,随着树脂基体中增韧剂含量的升高,环氧树脂浇注体拉伸弹性模量降低,其对应碳纤维增强复合材料单向层合板泊松比升高。增韧剂含量对单向复合材料压缩模量的影响不明显,但复合材料纵向压缩强度会随着增韧剂含量的升高而降低。     

阻燃高抗冲聚苯乙烯/弹性体复合材料性能研究

分别以弹性体SBS、POE和EVA为增韧剂,对阻燃高抗冲聚苯乙烯(HIPS)进行增韧改性,研究了增韧剂的引入对阻燃HIPS力学性能、阻燃性能和热稳定性的影响,同时采用扫描电镜(SEM)分析了各弹性体在HIPS基体中的分散性以及它们与基体间的界面黏结性。结果表明:以SBS为增韧剂时,所得阻燃HIPS/弹性体复合材料的冲击性能、弯曲性能、阻燃性能、热稳定性、增韧剂在HIPS基体中的分散性及其与HIPS基体间的界面黏结性均优于以POE或EVA为增韧剂的复合材料,但是该阻燃HIPS/SBS复合材料的拉伸性能相对较差。     

双酚A及端羧基丁腈橡胶对环氧树脂的增韧作用

以2-乙基-4-甲基咪唑为固化剂,分别以端羧基丁腈橡胶(CTBN)、CTBN/双酚A(BPA)或BPA为增韧剂增韧环氧树脂,研究了环氧树脂增韧体系的微观形貌和力学性能,考察了不同混料方式对CTBN增韧环氧树脂性能的影响。结果表明:CTBN增韧环氧树脂能使其固化物的冲击韧性有所提高,但其他力学性能降低;采用环氧树脂先与其进行预聚反应再经固化剂固化的方法能提高CTBN对环氧树脂的增韧效果;用CTBN/BPA为增韧剂不仅可以大幅度提高材料的冲击强度和扯断伸长率,而且可以提高弯曲强度与模量,克服了CTBN单一增韧导致材料强度下降的不足。BPA的加入可使环氧树脂固化物体系的弯曲强度、冲击强度和扯断伸长率有较大幅度的提高。     

Preparation and properties of MWCNTs/poly(acrylonitrile‐ styrene‐butadiene)/epoxy hybrid composites

Poly(acrylonitrile‐styrene‐butadiene) (ABS) was used to modify diglycidyl ether of bisphenol‐A (DGEBA) type epoxy resin, and the modified epoxy resin was used as the matrix for making multiwaled carbon tubes (MWCNTs) reinforced composites and were cured with diamino diphenyl sulfone (DDS) for better mechanical and thermal properties. The samples were characterized by using infrared spectroscopy, pressure volume temperature analyzer (PVT), thermogravimetric analyzer (TGA), dynamic mechanical analyzer (DMA), thermo mechanical analyzer (TMA), universal testing machine (UTM), and scanning electron microscopy (SEM). Infrared spectroscopy was employed to follow the curing progress in epoxy blend and hybrid composites by determining the decrease of the band intensity due to the epoxide groups. Thermal and dimensional stability was not much affected by the addition of MWCNTs. The hybrid composite induces a significant increase in both impact strength (45%) and fracture toughness (56%) of the epoxy matrix. Field emission scanning electron micrographs (FESEM) of fractured surfaces were examined to understand the toughening mechanism. FESEM micrographs reveal a synergetic effect of both ABS and MWCNTs on the toughness of brittle epoxy matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synergistic improvement of mechanical and thermal properties in epoxy composites via polyimide microspheres

Achieving synergetic improvements of mechanical strength, toughness, and thermal stability of epoxy resin has been a crucial but very challenging issue. Herein, to explore a new solution for circumventing this issue, polyimide microspheres were successfully prepared through the inverse nonaqueous emulsion process, and the structure, size distribution and morphologies of polyimide (PI) microspheres were comprehensively investigated. Then the PI microspheres were incorporated in epoxy resin matrix to systematically investigate the mechanical and thermal properties of obtained epoxy/PI microspheres composites. It was found that the PI microspheres can not only enhance the mechanical strength of epoxy resin, but also significantly improve the toughness. Specially, the epoxy-based composites containing 3 wt% PI microspheres exhibit a 47% increase in tensile strength, while the G_IC and Charpy impact strength increase by 106% and 200%, respectively. The toughing mechanism of epoxy/PI microspheres composites was discussed. Moreover, the PI microspheres can also endow the epoxy resin with excellent thermal stability and heat resistance. Thus, this work may open a new opportunity to synergistically enhance the mechanical and thermal properties of epoxy-based composites and may also give some valuable inspiration for the rational design of other high-performance thermosetting composites.     

Preparation and properties of TiO2‐filled poly(acrylonitrile‐butadiene‐styrene)/epoxy hybrid composites

Poly (acrylonitrile‐butadiene‐styrene) (ABS) was used to modify diglycidyl ether of bisphenol‐A type of epoxy resin, and the modified epoxy resin was used as the matrix for making TiO₂ reinforced nanocomposites and were cured with diaminodiphenyl sulfone for superior mechanical and thermal properties. The hybrid nanocomposites were characterized by using thermogravimetric analyzer (TGA), dynamic mechanical analyzer (DMA), universal testing machine (UTM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The bulk morphology was carefully analyzed by SEM and TEM and was supported by other techniques. DMA studies revealed that the DDS‐cured epoxy/ABS/TiO₂ hybrid composites systems have two T_gs corresponding to epoxy and ABS rich phases and have better load bearing capacity with the addition of TiO₂ particles. The addition of TiO₂ induces a significant increase in tensile properties, impact strength, and fracture toughness with respect to neat blend matrix. Tensile toughness reveals a twofold increase with the addition of 0.7 wt % TiO₂ filler in the blend matrix with respect to neat blend. SEM micrographs of fractured surfaces establish a synergetic effect of both ABS and TiO₂ components in the epoxy matrix. The phenomenon such us cavitation, crack path deflection, crack pinning, ductile tearing of the thermoplastic, and local plastic deformation of the matrix with some minor agglomerates of TiO₂ are observed. However, between these agglomerates, the particles are separated well and are distributed homogeneously within the polymer matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

基体性能对芳纶Ⅲ纤维复合材料力学性能的影响

设计了三种环氧树脂基体,研究了基体性能对芳纶Ⅲ纤维复合材料力学性能的影响,对比分析了不同韧性的两种复合材料层间剪切破坏过程的声发射特性参数。结果表明:设计的R1、R2、R3三种树脂基体其韧性为R1R2R3;芳纶Ⅲ纤维复合材料层间剪切强度分别为49 MPa、44.8 MPa、40.1 MPa,层间剪切性能随树脂基体韧性的增加而增大;声发射实验表明,基体韧性增加,复合材料急剧损伤得到延迟,声发射事件数明显减少。     

环氧树脂/碳化硅复合材料的热性能及韧性

采用碳化硅作为增强剂制备了环氧树脂/碳化硅复合材料,考察了复合材料的热学及力学性能。实验结果表明,碳化硅的添加使环氧树脂的玻璃化温度提高。当碳化硅添加质量分数为3%时,复合材料的韧性与纯环氧树脂相比提高了35%。     

Study of the effect of poly(acrylonitrile‐co‐butadiene‐co‐styrene) on the mechanical properties of an epoxy system

The mechanical properties of an epoxy system containing a diglycidyl ether of bisphenol A and 1,3‐bis(aminomethylcyclohexane) modified with different amounts of poly(acrylonitrile‐co‐butadiene‐co‐styrene) (ABS) were studied. Properties examined include tensile stress, percentage strain, tensile modulus, and tensile toughness determined in tensile tests, Rockwell hardness, and energy and maximum force to break a specimen in Charpy impact tests. The effect of the modification produced with the ABS was also studied using statistical methods including analysis of variance and multiple comparisons. The obtained data showed a significant effect of the modification produced with the ABS on the mechanical properties of this epoxy system, especially with the amount of 5 ABS per hundred parts of resin on the tensile properties and on the hardness. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 461–467, 2004     

The synthesis of a secondary branched epoxy-modified silicone resin and its application at low temperature

To enhance the fracture toughness of epoxy resin at low temperature, a secondary branched epoxy-terminated silicone resin (ESR-6) was synthesized and incorporated into bisphenol A epoxy resin at different contents. The structure of ESR-6 was characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance (¹H NMR), and the fracture surface of the composites was observed by scanning electron microscope (SEM) and atomic force microscopy. At room temperature and − 70°C, the maximum values of elongation at break were 15.78% and 12.55% with 10 wt% ESR. Compared with those of neat epoxy resin, the values of elongation at break of the composite were increased by 50.86% and 36.12%. The results of dynamic mechanical analysis also showed that the toughness of the modified resin had been improved. The SEM images of the fracture surfaces suggested that the fracture mode of the modified resin changed from brittle one to plastic one because of the addition of ESR-6, which further confirmed the toughening effect of ESR-6. These research results may provide a new strategy for enhancing the low-temperature toughness of epoxy resins.     

Preparation of epoxy resin using n-hexadecane based shape stabilized PCM for applying wood-based flooring

Epoxy resin has excellent characteristics of moisture, low toughness, solvent and chemical resistance, low shrinkage on cure, superior electrical and mechanical resistance properties, and good adhesion to many substrates. In this experiment, we prepared epoxy resin with shape stabilized phase change material (SSPCM) to enhance the thermal properties of epoxy resin. The SSPCM was prepared through the vacuum impregnation method, and the SSPCM/epoxy resin composites were prepared through the shear stirring process and curing process. In the preparation process, the epoxy resin and hardener were mixed in a beaker at a one-to-one ratio. Then, 5, 10, 15, and 20 wt.% of the SSPCM was added to the mixture. The thermal properties and chemical properties of epoxy resin with SSPCM were analyzed from scanning electron microscopy, differential scanning calorimetry, thermal gravimetric analysis, and universal testing machine analyzer. From the analysis, we determined that the prepared epoxy resin with SSPCM has heat storage capacity and high thermal conductivity, compared with the epoxy resin.     

玻纤增强ABS复合材料的制备及性能

以丙烯腈-丁二烯-苯乙烯共聚物(ABS)及玻璃纤维(GF)为原料,以环氧树脂作为界面相容剂,研究了界面相容剂对玻璃纤维增强ABS复合材料力学性能及界面粘接的影响.结果表明:加入环氧树脂,玻纤增强ABS复合材料的力学性能明显提高;随着玻纤质量分数的增加,复合材料的拉伸强度、弯曲强度、冲击强度均逐渐增加;玻纤质量分数为30%时,GF/ABS/环氧树脂复合材料的拉伸强度比未改性的复合材料的拉伸强度提高了30%,弯曲强度提高了25%,冲击强度也提高了50%.     

Fracture and mechanical properties of epoxy resins and rubber-modified epoxy resins

Fracture and mechanical property data on a wide range of epoxy resin systems are presented. The extent to which toughening can be induced by heterophase rubber inclusions depends more on the curing agent used than on the resin component. The greatest improvements in toughness were obtained by rubber modification of epoxy resins cured with an anhydride. A preformed ABS polymer can be used to toughen many epoxy resin systems. With one major exception (where a large improvement was found) only small changes in tensile properties occur when small amounts of rubber are present.