耐高温定形相变材料对聚酰胺6熔体流变行为的影响

为了研究定形相变材料(ssPCM)的引入对聚酰胺6(PA6)可纺性能的影响,采用环境扫描电镜观察了ssPCM在PA6基体中的分散情况,并使用毛细管流变仪对系列PA6/ssPCM复合材料的流变性能进行了分析。结果表明:ssPCM在PA6基体中分布均匀,未出现明显团聚,显示出良好的分散性;PA6/ssPCM熔体表现出明显的剪切变稀特性,属于非牛顿流体行为;随着ssPCM质量分数的增加,PA6/ssPCM熔体的剪切变稀现象更加显著;当ssPCM质量分数增加至20%时,PA6/ssPCM的非牛顿指数从0.735降至0.536,而结构黏度指数从0.406增加至0.683。此外,PA6/ssPCM的黏流活化能随剪切速率的增加而降低,即熔体黏度对温度的敏感性随着剪切速率的增加而减弱。

High-performance all-solid-state polymer electrolyte with fast conductivity pathway formed by hierarchical structure polyamide 6 nanofiber for lithium metal battery

The utilization of all-solid-state electrolytes is considered to be an effective way to enhance the safety performance of lithium metal batteries.However,the low ionic conductivity and poor interface compatibility greatly restrict the development of all-solid-state battery.In this study,a composite electrolyte combining the electrospun polyamide 6(PA6)nanofiber membrane with hierarchical structure and the polyethylene oxide(PEO)polymer is investigated.The introduction of PA6 nanofiber membrane can effectively reduce the crystallinity of the polymer,so that the ionic conductivity of the electrolyte can be enhanced.Moreover,it is found that the presence of finely branched fibers in the hierarchical structure PA6 membrane allows the polar functional groups(C=O and N-H bonds)to be fully exposed,which provides sufficient functional sites for lithium ion transport and helps to regulate the uniform deposition of lithium metal.Moreover,the hierarchical structure can enhance the mechanical strength(9.2 MPa)of the electrolyte,thereby effectively improving the safety and cycle stability of the battery.The prepared Li/Li symmetric battery can be stably cycled for 1500 h under 0.3 mA cm^(-2) and 60℃.This study demonstrates that the prepared electrolyte has excellent application prospects in the next generation all-solid-state lithium metal batteries.

COMPARISON OF POLYAMIDE 66/MONTMORILLONITE NANOCOMPOSITES PREPARED FROM POLYAMIDE 6 AND POLYAMIDE 66 BASED MASTER-BATCHES

Two master-batches,polyamide 66 (PA66)/organo-montmorillonite (OMMT) and polyamide 6 (PA6)/OMMT, prepared by melt compounding with methyl methacrylate (MMA) as co-intercalation agent,have been used to prepare nearly exfoliated PA661montmorillonite (MMT) nanocomposites.The resulting nanocomposites are compared in view of their morphology and properties.Nano-scale dispersion of OMMT is realized in both types of nanocomposites,as revealed by XRD,TEM and Molau tests.PA66/MMT nanocomposites having superior mecha...

INTERFACIAL MOLECULAR DESIGN OF A RIGID- PARTICLE TOUGHENED POLYAMIDE 6 COMPOSITE

The effects of interfacial modifier on the mechanical properties of kaolin-filled polyamide 6 (PA6) have been studied. The interracial interaction between polyamide 6 and kaolin has been character ized by means of infrared spectroscopy (IR) and scanning electron microscopy (SEM). The results show that the role of the interracial modifier lies in forming an elastic interlayer with good adhesion between kaolin and PA 6. A composite with high impact strength, high tensile strength and high elastic modulus can be obtained by inserting the elastic interfacial modifier into the rigid-particle-filled polymer system.

Synthesis and Electrical Properties of TiO_2 Nanoparticles Embedded in Polyamide-6 Nanofibers Via Electrospinning

We report on the synthesis and characterizations of TiO2 nanoparticles embedded in polyamide-6composite nanofibers by using electrospinning technique. The influence of substrate on the electrical characteristics of polyamide-6/TiO2 composite nanofibers was investigated. The resultant nanofibers exhibit good incorporation of TiO2 nanoparticles. The doping of TiO2 nanoparticles into the polyamide-6 nanofibers were confirmed by high resolution transmission electron microscopy and energy dispersive X-ray spectroscopy. Photoluminescence（PL） and cathodoluminescence（CL） spectroscopy were also used to characterize the samples.The PL and CL spectra reveal that the as-spun polyamide-6/TiO2 composite nanofibers consisted of overlapping of two broad emission bands due to the contribution of polyamide-6（centered at about 475 nm）, which might originate from organic functional groups of polyamide-6 and TiO2 nanoparticles（centered around 550 nm）. The electrical conductivity of the polyamide-6/TiO2 composite nanofibers on different substrates was carried out.It was found that the electrical conductivity of the polyamide-6/TiO2 composite nanofibers on silicon substrate was in the range of 13 μA, and about 1 to 20 p A for the paper and glass substrates.

聚酰胺(PA6)液相增粘反应技术的研究与开发

聚酰胺(PA6)作为重要的工程塑料之一,由于具有拉伸强度高、弹性模量大、耐磨损、自润滑和耐高温等特性,因此在汽车工业、电子行业、机械设备、海洋工程等行业得到广泛应用。本文主要针对聚酰胺(PA6)通过水解开环及固相增粘技术工艺存在反应效率低,工艺流程长,能耗高、分子量分布不均匀等缺点,通过PA6液相增粘反应技术小试试验研究,研究不同温度、停留时间及真空度下等条件下的增粘效果,其主要流程是缩聚反应完成之后的熔融物料直接进入液相增粘反应器中,通过双轴同向差速叶片连续搅拌不断的进行表面更新,同时低聚物、溶剂等小分子在更新表面溢出并被外部负压系统带走,完成增粘反应。聚酰胺(PA6)液相增粘反应技能耗显著降低,产品质量稳定,产品综合竞争力显著提高。

HCCP添加下建筑阻燃用PA6无纺布性能分析

聚酰胺6(PA6)是制备无纺布的主要化工材料,广泛应用于建筑阻燃领域。通过添加六氯环三磷腈(HCCP)可以更加有效地提高阻燃性能。采取熔喷工艺制备了一种PA6/HCCP无纺布,并通过实验测试的手段表征其阻燃性能。研究结果表明:HCCP与PA6范德华作用不能直接作用于PA6分子链,是以物理吸附方式与其他大分子相互作用,加入HCCP后可使提高PA6阻燃性能。添加HCCP后,织物面密度和厚度均减小,其厚度在1.2~1.7 mm之间,其表面密度大于261.4 g/m^(2)。该研究有助于提高对树脂高分子原理的认识,也可拓宽到其它的化工领域。

Numerical Simulation of Mechanical Properties of Nano Particle Modified Polyamide 6 via RVE Modeling

In this paper the physical influences on the mechanical behavior of a Polyamide 6 (PA 6)/Mont- morillonit (MMT)-nanocomposite are examined by a selected structure modification in a numerical parameter study. Experimental data of tensile tests of three different volume fractions at ambient temperature are used as reference. These were compared to homogenized stress-strain curves calculated with 3D representative volume elements (RVE) under periodic boundary conditions, in which the curve areas are considered until the tensile yield strength is reached. Besides the influence of filler orientation, exfoliation and its volume fraction, both adhesive interface behavior between the filler and matrix, and local partially crystalline interphases around the MMT-plates were also taken into account. A good approximation of the numerical representation of the experimental curves was achieved only after the introduction of the 30 - 40 nm thick partially crystalline interphases with higher stiffness and strength around the MMT-plates. The use of an exclusively isotropic matrix led to an underestimation of the mechanical values. The local modifications of the morphology were assumed to be transversely isotropic both in the elastic and in the plastic region. The transverse plane is defined by the lateral particle surface. Compared with the experimentally determined values of the corresponding Young’s Modulus, an excellent correlation was achieved. The yield strength for the largest volume fraction shows the best agreement with experimental values.

Modeling and Simulation of Mechanical Properties of Nano Particle Modified Polyamide 6

This paper discusses the utilization of nano-sized fillers in Polyamide 6 to increase the fracture resistance of the composites, which are crucial for various engineering applications. The toughening of the composites is achieved by using dispersed nano-scaled rubber particles (Polyether block copolymer) as the inclusion in Polyamide 6 matrix. For a better understanding of the mechanical behavior of the composites, it is indispensable to use analytical and numerical models for evaluating the overall mechanical behavior and damage mechanism of the composite. In this work the toughening mechanism is studied through literature review and by analytical modeling. The mechanical behavior of the composites such as elastic plastic and damage properties are calculated numerically with 3D representative volume element (RVE) models. The numerical results are compared with previously obtained experiments. The influence of volume fraction and aspect ratio of inclusions on the macroscopic stress strain curve as well as the size effect of inclusions and also the failure properties of the composite are studied in detail.

Preparation of porous polyamide 6(PA6)membrane with copper oxide(CuO)nanoparticles selectively localized at the wall of the pores via reactive extrusion

In this study,CuO nanoparticles are pre-modified with styrene-maleic anhydride copolymers(SMAs)of different molecular weights and MAH contents.Then the pre-modified CuO nanoparticles(CuO-SMAs)are added to the PA6/SEBS(Styrene Ethylene Butylene Styrene copolymer)(40/60 wt/wt)polymer blends with a co-continuous morphology.When SMA3(MAH=8 wt%,M_(n)=250000 g/mol)is used to modify CuO nanoparticles,and the grafting degree of SMA3 on the surface of CuO reaches 2.74 wt%,90.71%of the added mCuO-SMA3 nanoparticles can be located at the interface of PA6 and SEBS.A porous PA6 membrane with CuO nanoparticles located at the pore walls can be obtained after the SEBS phase is etched with xylene.The catalytic reaction velocity constant(k)for the reduction of p-nitrophenol in NaBH_(4)solutions with the PA6/mCuO-SMA3 porous membrane can reach 1.0040 min^(-1).This work provides a feasible and straightforward method for the preparation of porous polymer membranes with functional nanoparticles located at the wall of the pores.

Compatibility between Polyamide 6 and Polycarbonate Detected by SEM

Polyamide （PA6） and polycarbonate （PC） were prepared by a Brabender mixer （ PLV- 151） at 240℃ with 30 rpm for duration of 8 and 6 minutes respectively. The epoxy resin （E） addition can lead to substantial microstructural changes in the PA6/PC blends. Scanning electron microscope （SEM） was used to observe the mixtures characterized by the domains of clearly segregated homophases and voids between the two polymers. PA6/PC of polyamide 6 and polycarbonate with epoxy resin addition under the composition ratio of 20/80, 20/80/1, 40/60/1 and 40/60, were tested to verify the key role of epoxy in promoting the compatibility of PA6 with PC during blending.

单向CF/PA6复合材料性能劣化及老化寿命预测

利用热压成型工艺制备出碳纤维(CF)/尼龙6(PA6)复合材料单向板,并将复合材料试样置于蒸馏水热水浴中,分别在25,60,80℃下进行不同时间的湿热老化,再对湿热老化后复合材料试样进行吸湿测试、三点弯曲测试、微观形貌表征,探究复合材料的吸湿规律、力学性能劣化规律和微观形貌变化,并对复合材料的长期寿命进行预测。结果发现,复合材料在25,60℃下的吸湿行为基本符合Fick扩散定律,而80℃下在老化最后阶段出现了背离Fick扩散定律现象。复合材料的弯曲强度随老化温度、老化时间的增加呈下降趋势,分别在25,60,80℃下老化120 d后,试样弯曲强度分别下降了22.78%,25.0%,26.25%。但是老化温度、老化时间对弯曲弹性模量无显著影响,且CF与PA6树脂之间的界面黏合性能随着温度、时间的增加逐渐变差。以绍兴2021年平均温度作为服役温度,基于加速老化测试模型和阿伦尼乌斯理论建立了CF/PA6复合材料在服役环境下剩余弯曲强度的预测模型,可预测到1 400 d后,CF/PA6复合材料的弯曲强度保留率在64.8%左右。

基于二苯甲酮季铵盐化合物改善PA6的抗紫外性能

以2,4-二羟基-二苯甲酮、二甲氨基氯乙烷盐酸盐和溴代烷为原料,采用二步法制备了二苯甲酮季铵盐化合物(BP-Qas)。将BP-Qas引入聚己内酰胺(PA6)中,以溶液流延方式制备抗紫外PA6薄膜。其紫外光谱结果表明,当BP-Qas质量分数为1.5%时,抗紫外膜在200~350 nm实现了对紫外光线的零透过、零反射。同时,采用BP-Qas对PA6织物进行后整理,当pH=4、BP-Qas质量分数为3%时,PA6织物具有良好的抗紫外效果,其紫外线防护系数(UPF)达到50+。

凹凸棒石增强PA6复合线材制备及3D打印研究

为提高聚酰胺6(PA6)3D打印样件的力学性能,以凹凸棒石(ATP)为增强填料,通过γ-氨丙基三乙氧基硅烷(KH-550)表面改性ATP,采用熔融共混制备PA6/ATP复合材料并通过单螺杆挤出形成3D打印线材,研究了ATP在3D打印过程中的取向行为及其对PA6力学性能的影响,探讨了填料的增强机制。结果表明,适量的ATP能显著提升PA6的力学性能,拉伸强度和杨氏模量分别为73.8 MPa和3.11 GPa,较纯PA6提升35%和27%,ATP在PA6基体中有序取向。

呋喃基磷酰胺类阻燃剂的合成及其在阻燃PA6中的应用

为了抑制聚酰胺6(PA6)在燃烧过程中的放热情况,将可以在高温下成炭的呋喃基团引入到了阻燃剂中,设计并合成了一系列含有呋喃基团的阻燃剂,通过极限氧指数(LOI)、垂直燃烧试验和锥形量热仪对其阻燃抑热性能及机理进行了研究。结果表明,呋喃基团在不同的外部环境及内部形态下会表现出不同的抑热效果,加入了大分子阻燃剂的PA6样品在锥形量热仪测试中的抑热效果优于加入小分子阻燃剂的PA6样品。

玻纤增强PA6焊机外壳性能的影响因素数值模拟

深入探讨了玻璃纤维增强聚酰胺6在焊机外壳应用中的性能表现,并基于ANSYS软件平台,进行了静力学仿真和落球冲击仿真分析,旨在揭示玻纤含量、玻纤长径比以及玻纤取向等关键参数对焊机外壳性能的影响。静力学分析显示,当外壳承受2500 N的拉力时,玻纤含量的增加对焊机外壳应力强度的影响较小,但能够降低了外壳变形程度。当玻纤质量分数超过25%时,等效应力趋于稳定(约51 MPa)。此外,玻纤的取向对焊机外壳性能具有显著影响。当纤维沿X轴和Z轴取向且各占50%时(方向向量为a2),外壳的等效应力达54.6 MPa,同时变形量最小,仅为0.5 mm,这一性能与玻纤质量分数为40%的外壳相当。而玻纤长径比的增加对等效应力的影响并不显著,但有助于减少变形。进一步,通过落球冲击分析发现,随着玻纤含量的增加,外壳的等效应力逐渐增大,变形逐渐减小,这一趋势与静力学分析结果高度一致。当玻纤质量分数低于20%时,焊机外壳在冲击下易出现破裂;然而,当玻纤质量分数为20%~35%时,外壳表现出了优异的冲击性能,未出现开裂现象。

PBAT/PA6原位微纤复合材料的性能

为了对聚己二酸-对苯二甲酸丁二酯(PBAT)进行增强改性,选择尼龙6(PA6)作为分散相,采用自制的多级挤出拉伸装置制备了PBAT/PA6原位微纤复合材料。通过扫描电子显微镜、万能试验机、差示扫描量热仪与旋转流变仪对PBAT/PA6原位微纤复合材料的微观结构、力学性能、结晶性能及流变性能进行研究。结果表明,分散相PA6在PBAT基体中形成了微纤,当PA6质量分数为4%时,在PBAT-4试样的断面中PA6分散相呈短棒状形状,随着PA6含量的增大,PA6微纤平均直径逐渐增大,其直径分布范围也增大;当PA6质量分数为12%时,PBAT-12试样中的PA6微纤长度较长,大部分PA6微纤的长度大于30μm。PA6的加入提高了PBAT的结晶温度及屈服强度,PA6微纤对PBAT的结晶起到明显异相成核作用,使PBAT的结晶温度提高了14℃左右,PBAT/PA6原位微纤复合材料的玻璃化转变温度随PA6含量增加而逐渐向高温方向移动;随着PA6含量的增加,PBAT/PA6原位微纤复合材料的屈服强度及拉伸弹性模量先增大后减小,PBAT-12试样的屈服强度及拉伸弹性模量最大,分别为10.3MPa和233.5MPa。随着PA6微纤含量增加,PBAT/PA6复合材料的储能模量(G′)、损耗模量(G′′)和复数黏度(η*)值先增大后减小,PBAT-12试样呈现出最高的G′,G′′和η^(*)值。

PA6对LDPE/LLDPE薄膜性能影响的研究

研究了不同含量的PA6(聚酰胺6)对LDPE(低密度聚乙烯)/LLDPE(线性低密度聚乙烯)复合膜性能的影响。通过紫外-可见光-近红外吸收光谱、DSC(差示扫描量热法)熔融曲线、DSC结晶曲线和力学性能测试,系统分析了PA6含量对复合膜光学性能、热性能及力学性能的影响。结果表明,随着PA6含量的增加,LDPE/LLDPE/PA6膜的紫外吸收能力增强、透光率下降;复合材料硬度、弯曲强度和弯曲模量升高,拉伸强度增加,断裂伸长率下降。

阻燃抗熔滴PA 6膨体长丝的制备及其性能研究

采用自制的阻燃抗熔滴母粒与聚酰胺6(PA 6)切片共混,通过熔融纺丝-拉伸-变形一步法制备阻燃抗熔滴PA 6膨体长丝,重点研究母粒含量对纤维阻燃抗熔滴性能的影响,并对纤维形貌、力学性能、热收缩性能和结晶性能进行表征。结果表明:阻燃抗熔滴PA 6膨体长丝单纤维直径约50μm,截面为弧边三角形,随着母粒含量的增加,纤维的变形蓬松效果变差;随着母粒含量的增加,阻燃抗熔滴PA 6膨体长丝的极限氧指数(LOI)增加,母粒质量分数为7.5%时纤维LOI达29%,母粒质量分数为10.0%时纤维LOI达33%,且抗熔滴性好;随着母粒含量的增加,阻燃抗熔滴PA 6膨体长丝的断裂强度变化不大,约2.60 cN/dtex,母粒质量分数为7.5%时纤维综合力学性能最好;随着母粒含量的增加,阻燃抗熔滴PA 6膨体长丝的沸水收缩率降低,玻璃化转变温度、熔程先降低后升高,熔融峰顶温度、熔融热焓、结晶度先升高后降低;综合考虑纤维的阻燃抗熔滴性及力学性能,同时兼顾纤维的蓬松性,制备阻燃抗熔滴PA 6膨体长丝时添加阻燃抗熔滴母粒质量分数为7.5%较合适。

端氨基含量对PA 6非等温结晶动力学的影响

为探究端氨基含量对聚酰胺6(PA 6)非等温结晶动力学的影响,以端氨基含量分别为57.5,70.7,83.4 mmol/kg的PA 6(相对黏度均为2.8)为研究对象,使用热重分析仪测试PA 6的热稳定性,利用差示扫描量热仪研究不同冷却速率(∅)下PA 6的非等温结晶过程,通过Jeziorny法和莫志深法修正的Avrami方程对PA 6的非等温结晶动力学进行分析,并运用Kissinger方程计算PA 6的非等温结晶活化能(△E)。结果表明:不同端氨基含量PA 6均具有较高的热稳定性,且随着端氨基含量增加,热稳定性逐渐提高;随着∅的增大,不同端氨基含量PA 6的结晶区间均有向低温区移动的趋势;PA 6晶体以二维片状和三维球晶共存的方式进行生长,且端氨基含量较高的PA 6更倾向于以三维球晶的形式进行生长,端氨基含量的增加对PA 6的结晶过程具有促进作用;莫志深法修正的Avrami方程能很好地描述结晶过程,单位时间内PA 6的结晶度与∅成正比;随着端氨基含量的增加,PA 6非等温结晶活化能增大,结晶过程释放的热量增加,分子链的运动能力增强,结晶速率更大,结晶能力更强。