PE⁃g⁃MAH对聚酰胺6/导电炭黑复合材料性能的影响

采用马来酸酐接枝聚乙烯（PE-g-MAH）以同时提高聚酰胺6/导电炭黑（PA6/CB）复合材料的抗静电性能和韧性,利用双螺杆挤出机和注射成型机制备了系列PA6/CB、PA6/PE-g-MAH和PA6/PE-g-MAH/CB复合材料,并通过扫描电子显微镜（SEM）、差示扫描量热仪 （DSC） 等观察和表征了材料的形貌和结晶性能,测试了材料的力学性能和抗静电性能。结果表明,添加7.5 %（质量分数,下同）的CB后PA6韧性显著降低,CB对PA6结晶有异相形核作用;PE-g-MAH与PA6有较好的相容性,PE-g-MAH韧相能均匀分散在PA6和PA6/7.5 %CB中;添加PE-g-MAH后可提高CB在PA6中的分散性,改变CB的选择性分布,提高PA6/PE-g-MAH/7.5 %CB三元复合材料的电导性能;添加PE-g-MAH还可显著提高PA6和PA6/CB7.5 %的冲击强度和断裂伸长率;添加少量PE-g-MAH能促进复合材料中PA6的结晶。     

PA 12导电复合材料的结构与性能

采用熔融共混的方法制备了炭黑含量不同的聚酰胺(PA)12导电复合材料,研究了复合材料的导电性能、结构以及炭黑的分散状况。复合材料的体积电阻率随炭黑含量的增加而显著降低,导电炭黑的逾渗阈值低于15%。炭黑具有异相成核的作用,可提高PA 12初始结晶温度。复合材料的储能模量随炭黑含量增加而升高,炭黑对PA 12的分子运动有明显的阻碍作用,使复合材料的玻璃化转变温度移向高温方向。炭黑在PA 12基体中分散较均匀,随炭黑含量增加,炭黑颗粒间距减小,使PA 12复合材料具有良好的导电性能,体积电阻率最低为1×105Ω.cm。     

分散剂在聚丙烯/炭黑抗静电材料中的应用

应用两种分散剂(Altfona 3050和 Altfona 3020)制备了聚丙烯/炭黑(PP/CB)复合材料,在 PP 中添加8份 CB和2份分散剂1时,PP/CB/分散剂1复合材料的体积电阻率从8.25×10~(16) Ω·cm 下降至1.08×10~6 Ω·cm,得到了静电消除材料。分散剂1和2在降低 PP/CB 复合材料体积电阻率的同时,对基体材料的拉伸强度影响不大。扫描电子显微镜分析表明,在 PP/CB 复合材料中,CB 在分散剂1的良好润湿下的分散粒径达到纳米尺度。     

分散剂对PA6纤维蓝色母粒着色性能的影响

以纺丝级聚酰胺(PA)6为载体树脂,酞菁蓝9680,K7090,BGSP–3SD为颜料,A–C540A,AClyn295A,A–C6A为分散剂制备纤维用蓝色母粒,并将制得的蓝色母粒用于PA6着色。用Datacolor测色仪测定材料的着色性能,用光学显微镜观察颜料的分散性,研究了三种颜料及三种分散剂对PA6纤维母粒色彩性能及分散性的影响。结果表明,三种颜料的着色力度相差不大,其中酞菁蓝9680分散相对较好;分散剂A–C540A相对更适用于PA6纤维原液着色,当其添加量为7%时,着色力达到119.73%,着色性能提高显著。     

玻纤增强尼龙6的挤出工艺及力学性能

采用长玻纤连续添加和短切玻纤制备了玻纤增强尼龙6(PA6)复合材料。主要考察了玻纤含量、玻纤种类以及挤出工艺条件对复合材料力学性能的影响,并利用扫描电子显微镜对复合材料的冲击断面和拉伸断面及玻纤形态进行了观察。结果表明,采用短切玻纤加入时,玻纤含量对GF/PA6复合材料的力学性能影响很大。随玻纤含量的增加,复合材料的力学性能越来越高,断裂伸长率变低。加工工艺参数对复合材料的力学性能有影响。采用长玻纤连续添加时,玻纤的添加位置对复合材料的性能影响不大。在玻纤含量相同时,采用长玻纤连续添加得到的材料力学性能明显优于采用短切玻纤时的性能。玻纤能均匀地分散在PA6基体中,玻纤的保留长度和长度分布对复合材料的性能有直接影响。     

SDS改性凹凸棒土的制备及其在PA6中的应用

以焦磷酸钠为分散剂,十二烷基磺酸钠(SDS)为改性剂,采用超声波与机械搅拌的方法对凹凸棒土(ATP)进行表面改性,制备出有机改性凹凸棒土(OATP),考察了不同pH值对改性效果的影响。利用FTIR、XRD、沉降试验、TEM等对改性前后的ATP进行表征。结果表明:SDS不能扩大ATP的层间距,只能以吸附的方式附着其表面,且pH为7时吸附效果最佳;OATP在有机介质中表现出很好的分散性。将OATP与聚酰胺6(PA6)经双螺杆挤出机熔融共混得到PA6/OATP复合材料,研究了OATP用量对该复合材料力学性能的影响;利用DSC分析了PA6/OATP复合材料热性能的变化。结果表明:当OATP用量为6份时,PA6的结晶度提高了18.2%,拉伸强度和弯曲强度分别较纯PA6提高了17.5%和13.9%。     

HDPE/CB/PA6复合材料的导电与力学性能研究

为了改善尼龙6低温与干态存在着冲击强度低、纤维状易于电荷富集的缺陷,制备了高密度聚乙烯(HDPE)/导电炭黑(CB)/尼龙6(PA6)复合材料。首先制备了HDPE/CB共混物作为功能改性剂,再以马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)为增容剂,通过双螺杆挤出机熔融共混制备了HDPE/CB/PA6复合材料。通过扫描电子显微镜(SEM)、万能试验机、高阻计等方法,研究了添加增容剂和HDPE与PA6配比以及导电炭黑粒子含量对复合材料力学性能和导电性能的影响。结果表明,加入5 phr的增容剂POE-g-MAH,明显提高了HDPE与PA6的界面黏附力,复合材料相容性较好;当HDPE与PA6的质量比为35/65时,复合材料的断裂伸长率从纯PA6的88%增加到251%,缺口冲击强度从12.5 kJ/m~2增加到53.7 kJ/m~2;当导电炭黑的含量增加到2.5 phr时,复合材料的室温体积电阻率降低了7~10个数量级,约为10~8Ω·cm。     

聚酰胺用蓝色母粒的制备与分散性能研究

以低密度聚乙烯为载体树脂,酞菁蓝为颜料,聚乙烯蜡、乙烯丙烯酸共聚物(AC–540A)为分散剂,用双螺杆挤出造粒法制备颜料含量为20%的蓝色母粒。将制得的蓝色母粒用于聚酰胺(PA)6的着色。评价了不同分散剂种类及含量对PA6色彩性能和颜料分散性能的影响。结果表明,选用AC–540A为分散剂,其含量为3%时,PA6制品的–b*值最大(蓝色最明显),反射率最高,透射率最低,以偏光显微镜观察发现酞菁蓝颜料在PA6中分散均匀。     

PE管材中炭黑分散影响因素的研究

利用转矩流变仪研究了PE本色树脂和不同炭黑色母料混合后炭黑分散的情况，重点考察了混合温度、混合时间、转速等对炭黑分散的影响。结果表明，温度对炭黑分散影响较大，混合温度高于色母料熔点50℃为最佳炭黑分散温度；在不影响产物性能的混合时间范围内时间和转速对炭黑分散影响相对较小。在最佳混合条件下，本色树脂添加质量分数为2．5％．4％的炭黑色母料可以制得合格的PE产品。不同色母料对炭黑分散有明显的影响，其优劣通过最佳混合条件下混合产物显微观察得出。     

PP-g-MAH对尼龙6/炭黑复合材料性能和形貌的影响

以炭黑(CB)为导电填料,马来酸酐接枝聚丙烯(PP-g-MAH)为增韧剂,通过双螺杆挤出机和注射成型机制备了尼龙(PA)6/PP-g-MAH/CB复合材料,研究了PP-g-MAH含量对7.5%CB填充PA6力学性能、抗静电性能、热稳定性能和形貌的影响。结果表明,添加质量分数20%的PP-g-MAH可提高PA6/CB复合材料的拉伸强度、韧性、抗静电性能和热稳定性。PA6/PP-g-MAH/CB复合材料力学强度和热稳定性的提高源于PP-g-MAH产生的能量耗散以及CB,PP-g-MAH与PA6之间较好的界面粘附和PP-g-MAH均匀细化分散在PA6/CB中。PP-g-MAH改变了CB在共混物中的选择性分布,使PA6/CB的表面电阻率和体积电阻率分别下降5个和3个数量级。     

Effect of morphology on the electric conductivity of binary polymer blends filled with carbon black

Several carbon black (CB)‐filled binary polymer blends were prepared in Haake rheometer. Distribution states of CB and effect of morphology on the electric conductivity of different ternary composites were investigated. Under our experimental condition CB particles located preferentially at the interface between polymethyl methacrylate (PMMA) and polypropylene (PP) in PMMA/PP/CB composites, in high‐density polyethylene (HDPE) phase in PP/HDPE/CB composites, and in Nylon6 (PA6) phase in polystyrene (PS)/PA6/CB, PP/PA6/CB, PMMA/PA6/CB, and polyacrylonitrile (PAN)/PA6/CB composites; the ternary composites in which CB particles locate at the interface of two polymer components have the highest electric conductivity when the mass ratio of the two polymers is near to 1 : 1. The ternary composites in which CB particles located preferentially in one polymer have the highest electric conductivity usually when the amount of the polymer component having CB particles is comparatively less than the amount of the polymer component not having CB particles; if the formulations of PS/PA6/CB, PP/PA6/CB, and PMMA/PA6/CB composites equaled and PA6/CB in them is in dispersed phase, PS/PA6/CB composites have the highest electric conductivity and PP/PA6/CB composites have the lowest electric conductivity; suitable amount of PS or PAN in PA6/CB composites increase the electric conductivity due in the formation of a parallel electrocircuit for electrons to transmit. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Influence of morphology on positive temperature coefficient effect for conductive polymer composites with carbon black dispersed at interface

Selective localization of carbon black (CB) at the interface of polymer blends was achieved by the method that EBA‐g‐MAH was first reacted with CB, and then blended with poly(ethylene‐co‐butyl acrylate)/nylon6 (EBA/PA6). In CB‐filled EBA/PA6 blends, EBA and PA6 phases formed cocontinuous morphology and CB was localized in PA6 phase. The percolation threshold was 5 wt%. A single PTC (positive temperature coefficient) effect was observed in this composite. The appearance of PTC effect was originated from the thermal expansion of EBA phase. In the EBA‐g‐MAH filled EBA/PA6 blends, TEM results showed that CB particles were induced by EBA‐g‐MAH to localize at the interface, resulting that the percolation threshold was much lower than that of EBA/PA6/CB. Influence of morphology on PTC effect of EBA/PA6/EBA‐g‐MAH/CB composites was studied. In the composites with sea‐island morphology, the conductive network was fabricated by dispersed phase and CB at the interface. Thermal expansion of matrix interrupted the contact of dispersed phases and conductive network formed by CB particles at the interface, resulting in the double PTC effect. The composites with co‐continuous morphology exhibited single PTC effect due to the fact that conductive network was only fabricated by CB localized at the interface. POLYM. ENG. SCI., 53:2640–2649, 2013. © 2013 Society of Plastics Engineers     

Nylon 6 induced morphological developments and electrical conductivity improvements of polypropylene/carbon black composites

In this study, a polar conductive filler [carbon black (CB)], a nonpolar polymer [polypropylene (PP)], and a polar polymer [nylon 6 (PA6)] were chosen to fabricate electrically conductive polymer composites by melt blending and compression molding. The morphological developments of these composites were studied. Scanning electron microscopy results showed that in a CB‐filled PP/PA6 (CPA) composite, CB particles were selectively dispersed in PA6 phases and could make the dispersed particles exist as microfiber particles, which could greatly improve the electrical conductivity. The PA6 and CB contents both could affect the morphologies of these composites. The results of electrical resistivity measurements of these composites proved the formation of conductive networks. The resistivity–temperature behaviors of these composites were also studied. For CB‐filled PP (CP) composites, there were apparent positive temperature coefficient (PTC) and negative temperature coefficient (NTC) effects and an unrepeatable resistivity–temperature characteristic. However, for CPA composites, there were no PTC or NTC effects from room temperature to 180°C, and the resistivity–temperature behavior showed a repeatable characteristic; this proved that CB particles were selectively dispersed in the PA6 phase from another point of view. All experimental results indicated that the addition of PA6 to a CP composite could lead to an expected morphological structure and improve the electrical conductivity of the CP composite. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of Mixing Process and Morphologies on the Electrical Conductivity of PA6/EVA/CB Composites

Nylon6 (PA6)/Ethylene-(vinyl acetate) (EVA)/carbon black (CB) composites with different electrical conductivity were prepared in an internal mixer. The factors influencing the electrical conductivity of the ternary composites were investigated, including mixing mode, mixing time and mass ratio of PA6 and EVA, and so on. Among three kinds of PA6/EVA/CB composites, including ones prepared by directly mixing (composites A), EVA and CB were mixed prior to melt-compounding with PA6 (composites B) and PA6 and CB were mixed prior to melt-compounding with EVA (composites C), the mixing time only significantly influenced the electrical conductivity of composites A. Good conductivity of the composites could be realized because the distance between CB particles became closer with the increasing of mixing time. However, the mixing time has no effect on the electrical properties of the composites B and the composites C, due to there were no CB particles migrated phenomenon happened. Scanning electron microscopy (SEM) was used to assess the fracture surface morphologies and the dispersion of the CB particles. The results showed that the dispersion of the CB particles significantly affects the electrical conductivity of the composites. Based on the study of the influence of various mass ratios of EVA and PA6 on the morphologies and electrical properties of PA6/EVA composites filled with 10 phr (parts per hundred resins) CB particles, we suggested that the mass ratio of EVA and PA6 affected the volume resistivity of the ternary composites significantly. In addition, the composites were almost insulation when the mass ratios of EVA and PA6 were 80/20 and 70/30, while the composites became conductivity with the mass ratio of EVA and PA6 higher than 60/40. The PA6/EVA/CB composites which CB particles locate at the interface of EVA and PA6 have the lowest volume resistivity when the mass ratio of two components was 60/40.     

Phase morphology evolution and compatibilization of immiscible polyamide 6/polystyrene blends using nano‐montmorillonite

Nanocomposites of organic nano‐montmorillonite (nano‐OMMT)‐filled immiscible polyamide 6 (PA6)/polystyrene (PS) blends were prepared by three different processing methods. Masterbatch M1 of OMMT/PA6 and masterbatch M2 of OMMT/PS were prepared as separate masterbatchs by melt mixing with PA6 or PS, and then either mixed together or each mixed individually with appropriate amounts of PS or PA6, respectively. The effects of nano‐OMMT content and processing method on the structure, phase morphology, and mechanical properties of the PA6/PS/OMMT nanocomposites were investigated by X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, and mechanical properties tests. The results showed that the nano‐OMMT by M1 and M2 masterbatches dispersed primarily as exfoliated platelets in the PA6 matrix in the final composites regardless of the method of preparation. A drastic decrease of dispersed PS phase size and a very homogeneous size distribution were observed with the addition of nano‐OMMT. The PA6/PS/OMMT nanocomposites prepared from the M2 displayed the smallest dispersed PS phase size and best distribution of OMMT. The improvement of the mechanical properties of the PA6/PS/OMMT nanocomposites was attributed to the enhanced compatibilization of the immiscible PA6/PS blends by using nano‐OMMT. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers     

聚丙烯/尼龙/玻璃纤维/炭黑四元双逾渗复合体系的压阻行为

研究了聚丙烯（PP）/尼龙（PA）/玻璃纤维（GF）/炭黑（CB）四元复合体系的逾渗现象与压阻行为。通过SEM分析得出PA/CB体系的逾渗作用及其包裹GF对PP逾渗作用形成的导电网络是四元体系导电的根源,而且电阻的变化与GF的含量密切相关。GF低含量下出现微弱的NPC现象,在高含量下随应力的增大先出现的NPC现象,后出现PPC现象,本文对两种现象出现的原因进行了理论阐述。经多次应力循环,体系电阻的稳定性得到很大改善。     

The influence of carbon black batches on the fracture behavior of glass fiber reinforced PA6/PA66 blends

The toughness behavior of 30 wt % glass fiber reinforced PA6/PA66 blends colored with different masterbatches containing carbon black (CB) was characterized by the instrumented Charpy impact test. Two different CB types with different particle diameters as well as two different polymers, PE and PA6, were used to prepare the masterbatches. The CB concentration was varied from 0 to 1.2 wt % in the compounds and all materials were examined dry and after water absorption. The toughness of the compounds significantly decreased when CB was incorporated. Moisture conditioning of the materials led to increased toughness and ductility but did not compensate for the negative influence of CB. Using PE as a masterbatch polymer succeeded in limiting the influence of CB on toughness whereas the largest particle diameter led to the highest reduction in toughness. By taking into account crack resistance curves, it could be shown that there is a significant change in crack propagation behavior when the concentration of the larger particle CB exceeds a certain level; this was ascribed to the existence of complex CB structures at this concentration. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Cocontinuous phase morphology for an asymmetric composition of polypropylene/polyamide 6 blend by melt mixing of polypropylene with premelted polyamide 6/organoclay masterbatch

Cocontinuous morphology was obtained for an asymmetric composition of polypropylene/polyamide 6 (70/30 w/w) blend by controlling melt compounding sequence of PP, PA6, and organoclay. Three different compounding sequences were tested: direct melt mixing of all the components, melt mixing of PP with PA6/organoclay masterbatch, and melt mixing of PP with premelted PA6/organoclay masterbatch. Only the third method promotes cocontinuous morphology. In all three cases, organoclay locates preferentially in the PA6 phase and at the interface, although the level of organoclay dispersion is poorer in the case of direct mixing than in the two‐masterbatch approaches. The morphology evolution processes of the three different compounding sequences were investigated and revealed that the main reason for the formation of cocontinuous morphology in the third method is the inhibiting effect of organoclay preincluded in the premelted PA6 phase on phase inversion. The viscosity of PA6 phase and the barrier effect of organoclay were confirmed to be two key factors in promoting cocontinuous structure. Dynamic mechanical analysis shows that the blend having cocontinuous morphology displays higher storage modulus than those having matrix‐dispersed morphology at the same organoclay loading. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011