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。     

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。     

EVA/LDPE/CB导电复合材料结构与性能的研究

以炭黑(CB)粒子为导电填料,乙烯-乙酸乙烯共聚物(EVA)和低密度聚乙烯(LDPE)为基体树脂,在HAAKE转矩流变仪中制备了EVA/LDPE/CB导电复合材料,研究了CB粒子的分散形态、共混体系相形态以及其与EVA/LDPE/CB共混体系导电性能的关系。通过DSC、DMA、SEM、溶剂溶解等方法考察了EVA/LDPE两相体系随着EVA含量的变化引起的相转变情况,同时也考察了CB在EVA/LDPE共混体系中的选择性分散情况。     

熔融共混法丁腈橡胶/聚酰胺6复合材料的性能研究

为了考察丁腈橡胶(NBR)与聚酰胺6(PA6)共混产物综合性能变化,本文采用不同种类NBR与PA6熔融共混,考察共混过程中转矩值变化,表征了共混物的力学性能、耐溶剂性能,并且共混产物进行了红外光谱分析。研究结果表明:随着共混物体系中橡胶相含量的增加,共混物体系的熔体粘度上升。相同腈基含量下的NBR/PA6共混物的平衡转矩值随着NBR含量的增加而增加;拉伸强度随着共混物中NBR橡胶含量的上升,呈下降趋势。在相同的NBR含量条件下,拉伸强度随着腈基含量的增加而增加;红外测试结果显示NBR与PA间在高温高剪切作用下存在微化学反应,即双键与胺基间的反应;共混物体系中随着NBR含量的上升,共混物体系的体积溶胀率与质量溶胀率均呈上升趋势。     

尼龙66/聚酚氧共混体系的共混形态和力学性能

采用扫描电镜、动态力学分析仪和材料试验机研究了尼龙66(PA66)与聚酚氧(PHE)共混体系的共混形态和力学性能。研究表明:氢键作用使得二者熔融共混后形成部分相容的两相聚集态结构;以PA66为主体时,PHE以颗粒形态分散在PA66基体中,随PHE含量增加,分散相颗粒尺寸下降;此时尼龙相的玻璃化转变温度(Tg)增大,PHE相的Tg提高,共混体系拉伸强度增加,冲击强度下降。PA66/PHE质量比达到40/60后发生相反转,PA66分散相颗粒尺寸明显小于PHE为分散时相的颗粒尺寸。PHE相的Tg随PA66含量增加而增大,随PA66含量增加,共混体系拉伸强度和冲击强度均增大。     

酸酐化LLDPE/PS增容母料的制备及其应用

通过Friedel-Crafts烷基化反应和聚烯烃熔融接枝马来酸酐(MAH)技术,制备了酸酐化线型低密度聚乙烯(LLDPE)/聚苯乙烯(PS)增容母料,并用该母料增容LLDPE/PS/聚酰胺(PA)6三元共混物,考察了母料用量对LLDPE/PS/PA 6三元共混物结构及性能的影响。结果表明:酸酐化增容母料中主要含有MAH接枝LLDPE-g-PS与MAH接枝LLDPE,可用于提高LLDPE与PS和PA 6的相容性;该母料能有效增容LLDPE/PS/PA 6三元共混物,使三相之间界面作用增强,分散相粒径显著减小,力学性能提高;随着母料用量增加,共混物的熔体流动速率下降,LLDPE的结晶温度上升,而PA 6的结晶温度和PS的玻璃化转变温度呈下降趋势;当母料用量为8 phr时,共混物的力学性能和耐热性能最佳。     

熔融共混法丁腈橡胶/聚酰胺6复合材料的性能研究

丁腈橡胶是由丁二烯和丙烯腈通过乳液聚合而成的耐油型橡胶。因丁腈橡胶具有较好的耐油性、耐热性,已成为标准耐油橡胶弹性体制品。但是随着丁腈橡胶中丙烯腈百分含量增大,硫化胶耐油性能、耐磨性能、耐渗透性、耐热性、硬度及力学性能等获得提升。但其弹性、耐寒性能以及抗压缩永久变形性能降低。为了考察丁腈橡胶(NBR)与聚酰胺6(PA6)共混产物综合性能变化,本文采用不同种类NBR与PA6熔融共混,考察共混过程中转矩值变化,测试了NBR/PA6复合材料的力学性能以及耐溶剂性能。并对NBR/PA6进行了红外分析。研究结果表明:随着NBR/PA6体系中橡胶相(NBR)含量的增加,NBR/PA6熔体黏度上升。相同腈基含量下的NBR/PA6的平衡转矩值随着橡胶相(NBR)百分含量的增加而增大;拉伸强度随着NBR/PA6中橡胶相(NBR)百分含量的上升,呈现下降趋势。在相同的橡胶相(NBR)百分含量下,拉伸强度随着腈基百分含量的增加而增大;另外,在高温高剪切作用下,由红外分析知NBR与PA6间发生胺基与双键间的微化学反应;NBR/PA6体系中随着橡胶相(NBR)百分含量上升,NBR/PA6体系的体积溶胀率与质量溶胀率均呈上升趋势。     

PET/PE/CB导电母料的研制

采用分离喂料技术在聚对苯二甲酸乙二酯(PET)/聚乙烯(PE)共混物中加入导电炭黑(CB),通过布斯往复式脉动挤出机熔融共混、挤出造粒,制备了综合性能较好的纤维级PET/PE/CB导电母料。研究发现,以PET/PE不相容共混物代替PET作母料的基体树脂,能以较低的CB用量获得较好的导电性能;CB的质量分数为15%时,母料的体积电阻率随PET用量的增加呈先减小后增大的趋势,在PET与PE的质量比为60∶40时,母料的体积电阻率最低。     

CB/MWCNTs/PP导电复合材料的制备与性能表征

通过熔融共混、注塑成型将多壁碳纳米管(MWCNTs)母粒、炭黑(CB)母粒与聚丙烯(PP)混合制备CB/MWCNTs/PP导电复合材料。复合材料中导电填料MWCNTs体积分数为1%,通过改变炭黑体积分数,探究CB含量的变化对复合材料导电性能、力学性能和流变性能的影响。导电测试结果表明,当CB体积分数介于3%~5%时,复合材料达到电流逾渗;超声共振结果表明,复合材料的弹性模量会随着CB含量的增大而增大,而泊松比对CB含量的变化并不敏感;DMA结果表明,复合材料玻璃化转变温度(T_g)会随着CB含量的增加而降低,而储能模量和损耗模量在低温区会随着CB的增大而上升;MCR分析结果表明,当CB体积分数介于1%~3%时,复合材料达到流变逾渗,复合黏度对低频率扫描不敏感,随着CB体积分数的增大而增加。随着频率上升,不同含量材料的复合黏度越来越逼近,并且呈现剪切变稀现象。     

环氧树脂对PA6/EPDM-g-MAH共混体系性能的影响

将两种不同型号的环氧树脂（EP(903)、EP(619D)）分别与PA6/EPDM-MA体系进行共混,制备了PA6/EPDM-MA/EP三元共混物。通过力学测试、动态流变(DMA)、差示扫描量热法（DSC）研究了不同EP添加量和环氧当量对PA6/EPDM-MA/EP共混体系性能的影响。实验结果表明：添加EP可以提高PA6/EPDM-MA共混物的拉伸强度,缺口冲击强度,并随着EP含量的增加而增加;而PA6/EPDM-MA/EP三元共混体系的动态储能模量（G′）,复合黏度（η*）随着EP含量的增加而增大,损耗因子（tanδ）减小;结晶度比未加环氧的共混物的结晶度稍高,并且随着环氧含量增加先增加后降低。此外,添加EP(903)的共混物各种性能变化比EP(619D)快。     

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     

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.     

PA6/LDPE/PE-g-MAH共混纳米纤维的制备及结构研究

采用共混海岛纺丝法制备聚酰胺6/低密度聚乙烯/聚乙烯接枝马来酸酐(PA6/LDPE/PE-g-MAH)共混纤维,溶解剥离出LDPE基体相,可制备出PA6纳米纤维;研究了共混物的组成和纺丝条件对共混纤维的相结构、结晶、力学性能及PA6纳米纤维直径的影响。结果表明:随着共混物中PA6分散相含量增加,PA6纳米纤维的直径逐渐增大;PA6质量分数从30%增加至60%时,PA6纳米纤维平均直径由107 nm增至149nm;PA6质量分数为70%时,由于相逆转无法得到PA6纳米纤维;在PA6质量分数为55%条件下,提高拉伸倍数,PA6纳米纤维的直径进一步降低,且结晶度、力学性能增加。     

Improvement of melt spinning properties and conductivity of immiscible polypropylene/polystyrene blends containing carbon black by addition of styrene‐ethylene‐butene‐styrene block copolymer

Conducting polymeric materials prepared from immiscible blends, such as polypropylene (PP)/polystyrene (PS), together with carbon black (CB), are known to have a relatively high electrical conductivity, because of a selective distribution of CB (double percolation). Melt spinning of immiscible blends containing CB has, however, not been extensively reported on previously. An immiscible 1:1 blend of PP and PS to which 4 wt% CB was added exhibited a very low melt draw‐down ratio at rupture compared wit PP with the same content of CB. By adding 5 wt% SEBS (styrene‐ethylene‐butene‐styrene block copolymer), the ultimate melt draw‐down ratio increased about 10 times, which made the material more suitable for melt spinning. As‐extruded samples of the immiscible blends (with CB) did not have higher electrical conductivities than PP/CB. A heat treatment increased the conductivity of immiscible PP/PS/CB composites, and longer treatment times and higher temperatures promoted the conductivity. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Blend composition dependence of the compatibilizing efficiency of graft copolymers for immiscible polymer blends

This work is concerned with the dependence of the compatibilizing efficiency of graft copolymers on the composition of immiscible polymer blends. A series of graft copolymers of polystyrene (PS) and polyamide 6 (PA6), denoted as PS‐g‐PA6, with different molecular structures were used as compatibilizers. The PS‐g‐PA6 was more efficient for the PS/PA6 (80/20) blend than for the PS/PA6 (20/80) one, indicating that a graft copolymer whose backbone and grafts match the matrix and the disperse phase polymers, respectively, has higher compatibilizing efficiency. This is in disagreement with the literature. Moreover, whatever the blend composition, for PS‐g‐PA6 graft copolymers with the same backbone and the same number of grafts per backbone, the longer the grafts, the higher their compatibilizing and stabilizing efficiency; for a given backbone/graft mass ratio, the longer the grafts and concomitantly the smaller the number of grafts per backbone, the higher the compatibilizing and stabilizing efficiency of the graft copolymer. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

羧化聚苯乙烯增容PA1010/PS共混体系的形态及相容性研究

采用扫描电镜、动态粘弹谱和偏光显微镜等方法研究了羧化度的摩尔分数为３．２％时羧化聚苯然增容ＰＡ１０１０／ＰＳ共混体系的形态及相容性。结果表明,在ＰＡ１０１０／ＰＳ体系中ＣＰＳ的加入能有效地改善体系的相容性,这表现在加入ＣＰＳ后分散相与基体间的界面变得模糊。     

Electroconductive polyblend fibers of polyamide‐6/polypropylene/polyaniline: Electrical,morphological, and mechanical characteristics

Melt spun drawn fibers were prepared using a ternary blend of PP/PA6/PANI‐complex (polypropylene/polyamide‐6/polyaniline‐complex). Their electrical and mechanical properties were compared to those of binary blend fibers of PP/PANI‐complex. The results of the morphological studies on 55:25:20 PP/PA6/PANI‐complex ternary fibers were found to be in accordance with the predicted morphology for the observed conductivity vs. fiber draw ratio. The scanning electron microscopy (SEM) micrographs of the ternary blend illustrated at least a three‐phase morphology of a matrix/core‐shell dispersed phase style, with widely varying sizes of droplets. This resulted in a dispersed morphology that, in some parts of the blend, approached a bicontinuous/dispersed phase morphology due to coalescence of the small droplets. The matrix was PP and the core‐shell dispersed phase was PA6 and PANI‐complex, in which a part of the PANI‐complex had encapsulated the PA6 phase and the remaining was solved/dispersed in the PA6 core, as later confirmed by X‐ray mapping. When the ternary blend fibers were compared to the binary fibers, the formers were able to combine better conductivity (of an order of 10^?3 S cm^?1) with a greater tensile strength only at a draw ratio of 5. This indicated that the draw ratio is more critical for the ternary blend fibers, because both conductivity and tensile strength depended on the formation of fibrils from the core‐shell dispersed phase of the PA6/PANI‐complex. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Developing electrically conductive polypropylene/polyamide6/carbon black composites with microfibrillar morphology

We have established that the PP/PA6/CB composite with 3D microfibrillar conducting network can be prepared in situ using melt spinning process. CB particles preferably were localized at the interface between polypropylene as the matrix and PA6 microfibrils, which act as the conducting paths inside the matrix. The percolation threshold of the system reduced when aspect ratio of the conducting phase was increased by developing microfibrillar morphology. The effect of annealing process on the conductivity of PP/PA6/CB composite with co‐ continuous and microfibrillar morphologies was studied. It was observed that, annealing process forces CB particles towards the interface (2D space) of PP and PA6 co‐continuous phases, and percolation threshold and critical exponent of classical percolation theory will be decreased, while the conductivity of conducting composite with microfibrillar morphology was not affected considerably by annealing process at temperatures either higher or lower than the melting point of the PA6 microfibrils. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

PES/PA6的共混纺丝及其性能研究

将不同质量比的聚醚砜(PES)与聚酰胺6(PA6)共混进行熔融纺丝制得PES/PA6共混纤维;研究了共混物的流动性及其纺丝工艺,以及PES/PA6共混纤维的热稳定性和力学性能。结果表明:PA6的加入显著提高了PES的流动性,降低了纺丝温度,改善了PES的可纺性;与纯PES纤维相比,PES/PA6共混纤维的起始热分解温度有所降低,PES/PA6质量比为70/30～30/70的PES/PA6共混物的纺丝温度为320～340℃,卷绕速度为100～400 m/min,纤维的断裂强度为0.71～2.25 cN/dtex。