原位聚合法制备PA6荧光材料及其性能

将荧光粉分散到己内酰胺（CL）水溶液中,除水以后加入引发剂促使CL阴离子开环聚合制备了一组不同荧光粉含量的聚酰胺6（PA6）荧光材料样品并对其性能进行表征。结果表明,少量荧光粉的加入对PA6晶型影响不大;采用CL阴离子开环聚合制备的PA6荧光材料光至荧光强度较高,其光至荧光强度受其中荧光粉含量影响较大;荧光粉含量为0.15 %（质量分数,下同）的PA6荧光材料荧光强度最强;荧光粉在PA6荧光材料样品中分布比较均匀,且随着荧光粉含量的提高,荧光粉容易团聚;荧光粉的加入未改变PA6的热分解规律,PA6荧光合材料样品的最大分解温度均低于PA6;荧光粉会抑制PA6 γ晶型的形成,促进PA6 α晶型形成。     

聚酰胺6/环氧树脂改性蒙脱土纳米复合材料的制备与性能

采用环氧树脂改性蒙脱土（MMT）得到有机化蒙脱土（OMMT）,再用熔融插层法制备了聚酰胺6 （PA6）/ OMMT纳米复合材料。采用X射线衍射仪、透射电子显微镜、万能材料试验机、热重分析仪等研究了PA6/OMMT复合材料的形态结构、力学性能和热稳定性。结果表明,经环氧树脂改性得到的OMMT的层间距明显增加,从未改性的1.22 nm增加到5.13 nm,并以纳米尺度分散于PA6基体中;随着OMMT含量的增加,PA6/ OMMT复合材料的强度和模量增加,热变形温度提高,其拉伸强度可达76 MPa,弯曲模量达到3.462 GPa,热变形温度为134 ℃;PA6/ OMMT复合材料失重10 %时的温度为422 ℃,比纯PA6的406 ℃提高了16 ℃,改善了PA6的热稳定性。     

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。     

原位聚合制备SiO2高含量PA6/SiO2母料及其复合材料

采用溶剂转移法对二氧化硅(SiO₂)进行改性处理,并通过原位聚合方法制备了高含量聚酰胺6(PA6)/ SiO₂母料,并通过母料与外购纯PA6共混制备了纳米复合材料。通过X-射线衍射、透射电镜(TEM)等仪器分别对PA6/SiO₂纳米复合材料的结晶及晶型结构、微观分散形态进行了表征;并对纳米复合材料的力学性能等进行了测试。结果表明,改性后的SiO₂在PA6原位聚合体系中分散均匀且能够达到纳米级的分散效果,并会起到异相成核剂的作用。通过母料与纯PA6共混制备的SiO₂纳米复合材料与传统熔融法相比拉伸强度提高了12.17%,断裂伸长率提高了37.30%,缺口冲击强度提高了37.25%。     

聚酰胺6／凹凸棒土纳米复合材料的结构与性能研究

用聚丙烯酸钠（PAAS）及六偏磷酸钠（SHMP）对凹凸棒土（ATP）进行分散、提纯和改性处理；利用透射电镜研究了其在水中的分散情况；利用热失重、红外和XRD对改性前后的ATP进行了表征。结果表明：PAAS及SHMP都能较好地分散ATP，PAAS对ATP的提纯改性效果要优于SHMP。在反应釜内通过水解开环聚合制备了聚酰胺6／凹凸棒土（PA6／ATP）纳米复合材料，利用XRD和DSC等测试手段分析了该复合材料的结晶结构；通过TEM分析了ATP在该复合材料中的分散情况，并测定了其力学性能。结果表明：ATP在PA6基体中分散较为均匀，当ATP用量为3．5％时，PA6的结晶度增加4．5％，材料的弯曲强度、弯曲模量和拉伸屈服强度分别较纯PA6提高33．7％、32．5％和29．4％。     

无机成核剂改性聚酰胺6/碳纤维复合材料的结构与性能

以钛酸钾晶须（PTW）、高岭土（Kaolin）和滑石粉（Talc）为成核剂,制备了无机成核剂改性聚酰胺6/碳纤维（PA6/CF/NA）三元复合材料。通过分析复合材料的力学性能、动态热力学性能、微观形貌、结晶行为、晶体结构、热性能等对其结构和性能进行了系统的研究。结果表明,加入Talc可以大幅提高PA6/CF复合材料的冲击性能,添加2%（质量分数,下同）的Talc时,复合材料的冲击强度提高了44.5%;Talc在挤出过程中能够充分解离成片层并均匀地分散在PA6基体中,PA6/CF/Talc复合材料中存在大量纤维拔出后形成的孔洞,片层与基体黏结较好;与PTW和Kaolin相比,Talc突出的异相成核作用可以显著提高PA6/CF复合材料的结晶温度,并促进PA6形成更为完善的晶体结构。     

PS/PA6聚合物纳米合金的制备--共混方法对聚合物纳米合金的影响

用原位聚合/原位增容的方法,成功地制备了PS/PA6的纳米复合物。通过不同的共混方法发现,直接将PS和CL共混时,由于物料在混炼机中分布不均匀,很难得到分散均匀的纳米共混物;如果先将两者制成均匀的溶液而后再共混、聚合,则可以得到分散相粒径分布均匀的PS/PA6纳米复合物。     

Fe2O3/PA6复合材料的制备及性能研究

将通过液压-热晶法合成的纳米Fe2O3粒子加入到聚合反应体系中进行原位聚合,制得纳米Fe2O3/PA6复合材料。通过扫描电镜研究了纳米Fe2O3在PA6基体中的分散情况,将复合材料挤压成直径为1mm的细线,测试了其力学性能和热学性能。结果表明,纳米Fe2O3在基体中分散均匀,当纳米Fe2O3质量分数为16.7%时,复合材料的最大失重速率温度比纯PA6提高了16.0℃,热稳定性得到提高,拉伸强度和拉伸模量比纯PA6分别提高了27.78%和109%。     

马来酸酐含量及制备工艺对PA6/POE-g-MAH/Nano-CaCO3复合材料形态及力学性能的影响

通过改变共混物中乙烯辛烯共聚物（POE）与马来酸酐接枝POE（POE-g-MAH）的比例,研究了MAH含量对聚酰胺6（PA6）/POE/POE-g-MAH/纳米碳酸钙（nano-CaCO3）复合材料的微观结构和力学性能的影响。结果表明,MAH含量较高时,POE-g-MAH与PA6基体的相容性好,复合材料的冲击强度最高;制备工艺对复合材料的形态及力学性能有很大影响,采用两步法制备的复合材料中nano-CaCO3分散效果更好,其增容作用使弹性体分散相直径增大约100 nm,冲击强度较一步法提高21 %。     

螺杆构型对反应挤出制备聚乙烯/聚酰胺6原位合金的影响

以己内酰胺（CL）、高密度聚乙烯(PE-HD)、马来酸酐接枝高密度聚乙烯（PE-HD-g-MAH）为主要原料,采用反应挤出法制备PE-HD /聚酰胺6（PA6）原位合金,研究螺杆构型对PE-HD/PA6原位合金制备的影响。研究发现,停留时间长的螺杆构型,其对应的原位合金中CL单体转化率较高;在3种螺杆构型中,带有大导程拉伸元件的螺杆,所制备的原位合金中分散相PA6的粒径最小,其原因在于CL单体在PE-HD中的初始分散状态对合金中分散相PA6的粒径有直接影响,而大导程拉伸元件更有利于CL在PE-HD基体中的破碎与分散。     

Preparation and properties of PET/PA6 copolymer/montmorillonite hybrid nanocomposite

From in situ polycondensation, a poly(ethylene terephthalate)/Polyamide 6 copolymer/montmorillonite nanocomposite was prepared, after the treatment of montmorillonite (MMT) with a water soluble polymer. The resulting nanocomposites were characterized by X‐ray diffraction (XRD), differential scanning calorimeter (DSC), nuclear magnetic resonance (NMR), dynamic mechanical analysis (DMA), and transmission electron microscopy (TEM). The results of DSC, ¹H NMR, and DMA proved that the nanocomposite synthesized was PET/PA6 copolymer/MMT nanocomposite, not the PET/PA6 blend/MMT nanocomposite. The results of XRD and TEM proved that the dispersion of MMT was improved observably after the introduction of PA6 molecular chain into PET. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2512–2517, 2006     

尼龙6/高岭土纳米复合材料的结晶行为

采用广角X射线衍射仪(WAXD)、偏光显微镜和差示扫描量热仪(DSC)等手段研究尼龙6(PA6)/高岭土纳米复合材料的结晶行为.结果表明:高岭土的加入起到成核剂的作用,影响到PA6成核机理和结晶的生长,且改变了PA6的晶型,使PA6结晶温度略有升高,结晶速率增加,更易于结晶.同时从Avrami方程出发,得出纳米高岭土的存在可以明显改变PA6的结晶行为.     

Investigation on the polyamide 6/organoclay nanocomposites with or without a maleated polyolefin elastomer as a toughener

Polyamide 6 (PA 6)-based nanocomposites were prepared using a melt-mixing technique in this study. One commercial organoclay (denoted 30B) and one maleated polyolefin elastomer (denoted POEMA) served as the reinforcing filler and toughener, respectively. The X-ray diffraction (XRD), scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS) and transmission electron microscopy (TEM) results confirmed the nano-scaled dispersion of 30B in the composites. Different mixing sequences presented similar phase morphology for the same formulated nanocomposites. XRD results also revealed that both 30B and POEMA would induce the formation of γ form PA 6 crystal, with 30B exhibiting a higher efficiency. Differential scanning calorimetry (DSC) results indicated that the addition of 30B altered the crystallization kinetics of PA 6, which was mainly attributed to the prevailing formation of γ form crystal. Complex melting behaviors were observed for neat PA 6 and the nanocomposites. These complex behaviors are associated with different polymorphs and the ‘melting-recrystallization-remelting’ phenomenon. Moderate thermal stability enhancement of PA 6 after adding 30B and/or POEMA was confirmed using thermogravimetric analysis (TGA). The storage modulus, Young's modulus and tensile strength of PA 6 were increased after adding 30B. However, these properties declined after further incorporation of POEMA. The different-processed PA 6/30B/POEMA nanocomposites displayed balanced tensile properties and toughness between those of neat PA 6 and PA 6/30B nanocomposite.     

良好分散尼龙6/多壁碳纳米管复合材料的研究

采用柔和混合法制备纳米粒子良好分散的尼龙-6/多壁碳纳米管(PA6/MWNTs)复合材料,采用差示扫描量热仪(DSC)和广角X射线衍射法(XRD)研究了MWNTs对PA6基体结晶熔融行为的影响。DSC结果表明,MWNTs的加入大幅度地提高了PA6的结晶温度(最高提高约20℃),基体的结晶度也有所提高,说明良好分散的MWNTs在PA6结晶过程中呈现明显的异相成核作用;XRD结果证实,分散良好的MWNT促进PA6形成α晶型,抑制γ晶型的形成。同时,MWNT的加入导致复合材料出现熔融双峰现象,其形状随MWNT含量的变化而改变,双峰结构可能是由于熔融过程中伴随着重结晶而引起的。     

Study on the dynamic self‐organization of montmorillonite in two phases

Polycarbonate (PC)/acrylonitrile–butadiene–styrene (ABS) polymer alloy/montmorillonite (MMT) and nylon 6 (PA6)/ABS polymer alloy/MMT nanocomposites were prepared using the direct melt intercalation technique. Their structures were characterized by XRD and TEM. The results of TEM show that the silicate layers dispersed differently in two phases. In the PC/ABS/MMT nanocomposite, the silicate layers were self‐organized in the ABS phase, whereas in the PA6/ABS/MMT nanocomposite, the silicate layers were dispersed in both phases but mainly in the PA6 phase. Furthermore, the PC/MMT nanocomposite was melt‐mixed with pure ABS, and the changed morphology of the hybrid with the change of melt‐mixing time was characterized by XRD and TEM, to study the dynamic self‐assembly of clay layers in two phases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1457–1462, 2004     

Effect of clay modification on the morphological,mechanical, and thermal properties of polyamide 6/polypropylene/montmorillonite nanocomposites

Polyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic montmorillonite (OMMT) were prepared by melt compounding. The sodium montmorillonite (Na‐MMT) was modified using three different types of alkyl ammonium salts, namely dodecylamine, 12‐aminolauric acid, and stearylamine. The effect of clay modification on the morphological and mechanical properties of PA6/PP nanocomposites was investigated using x‐ray diffraction (XRD), transmission electron microscopy (TEM), tensile, flexural, and impact tests. The thermal properties of PA6/PP nanocomposites were characterized using thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and heat distortion temperature (HDT). XRD and TEM results indicated the formation of exfoliated structure for the PA6/PP nanocomposites prepared using stearylamine modified montmorillonite. On the other hand, a mixture of intercalated and exfoliated structures was found for the PA6/PP nanocomposites prepared using 12‐aminolauric acid and dodecylamine modified montmorillonite. Incorporation of OMMT increased the stiffness but decreased the ductility and toughness of PA6/PP blend. The PA6/PP nanocomposite containing stearylamine modified montmorillonite showed the highest tensile, flexural, and thermal properties among all nanocomposites. This could be attributed to better exfoliated structure in the PA6/PP nanocomposite containing stearylamine modified montmorillonite. The storage modulus and HDT of PA6/PP blend were increased significantly with the incorporation of both Na‐MMT and OMMT. The highest value in both storage modulus and HDT was found in the PA6/PP nanocomposite containing stearylamine modified montmorillonite due to its better exfoliated structure. POLYM. COMPOS., 31:1156–1167, 2010. © 2009 Society of Plastics Engineers     

Non‐isothermal crystallization kinetics of polyamide 1010/montmorillonite nanocomposite

The non‐isothermal crystallization kinetics of pure polyamide 1010 (PA1010) and PA1010/montmorillonite nanocomposite (PA1010/MMT) was investigated by differential scanning calorimetry (DSC) at various cooling rates. The Avrami analysis modified by Jeziorny and a new method developed by Mo can describe the non‐isothermal crystallization process of PA1010 and PA1010/MMT nanocomposite very well. The difference in the value of exponent n between PA1010 and PA1010/MMT nanocomposite suggests that the nano‐size montmorillonite layers act as nucleation agents of PA1010. The values of half‐time of crystallization and crystallization rate coefficient (CRC) show that the crystallization rate of PA1010/MMT nanocomposite is faster than that of PA1010 at a given cooling rate. Polym. Eng. Sci. 44:861–867, 2004. © 2004 Society of Plastics Engineers.     

Morphology and Osteogenetic Characteristics of Polyamide/ NanoHydroxyapatite Biocomposites

Summary  The effect of shear or time of shearing – as exerted by different screw configurations – upon the nano hydroxyapatite (n-HA) dispersion, during the twin screw extrusion processing for the preparation of PA6-66/n-HA composites, was investigated. Three different screw configurations, designated as medium, high and very high shear, were used. A noticeable improvement in the n-HA dispersion, attributed to the increasing shear exerted upon the melt during mixing in the TSE, was observed. Crystallization and thermal behavior of n-HA reinforced PA6-66 composites were studied by X-Ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). An increase in the crystallization temperature, accompanied by a decrease in percent crystallinity with the addition of n-HA to the PA6-66 matrix was observed. That is, n-HA acted as a nucleating agent and enhanced the crystallization rate. In addition, it was observed that the n-HA promoted the occurrence of the Brill transition. The decomposition temperature increased with the addition of n-HA. The PA6-66/ n-HA nanocomposite was thereafter, immersed in simulated body fluid (SBF) and the generation of a new calcium phosphate layer on the nanocomposite surface was monitored by SEM, FTIR and Atomic Absorption. The Ca/P ratio in the forming apatite layer started at a low value, ca. 1.3, which corresponds to octacalcic phosphate, but increased with the immersion time to 1.6, which corresponds to carbonated apatite.     

Effect of Compatibilizer Type on Properties of 70:30 Polyamide 6/Polypropylene/MMT Nanocomposites

PA6/PP nanocomposites with either polyethylene octene elastomer grafted maleic anhydride (POEgMAH) or PP grafted maleic anhydride (PPgMAH) as compatibilizer were prepared using co-rotating twin-screw extruder followed by injection molding. The mechanical and microstructural properties of the composites were investigated by means of tensile, flexural, and impact testing and by scanning electron microscopy (SEM). X-ray diffraction (XRD) was used to characterize the formation of nanocomposites. The result indicated that the miscibility of PA6/PP nanocomposites was improved with the addition of POEgMAH and PPgMAH. The impact strength of PA6/PP nanocomposite with POEgMAH increased about 5 times higher than uncompatibilized composite. Increment in tensile properties was observed when PPgMAH was used as compatibilizer. XRD results revealed that PA6/PP nanocomposites were successfully formed. Uniform dispersion of PP in matrix were observed through SEM, which showed the improvement of the compatibility between polymers.     

金属离子配位作用下PA6的受限结晶

采用熔融共混法,制备了聚酰胺6/氯化钙(PA6/CaCl2)复合材料。通过差示扫描量热法(DSC)、X射线衍射法(XRD)研究了PA6基体在受限条件下的非等温结晶及晶型转变行为。结果表明:金属离子Ca2+与酰胺基团的络合配位作用使PA6/CaCl2复合材料中PA6的结晶行为和结晶度受到了限制。随着CaCl2含量的增加,PA6的结晶度、结晶峰温度、熔融峰温度逐渐降低,结晶速率减小,结晶半峰宽增大,当CaCl2的含量大于8%时,PA6变为无定形态;此外,CaCl2的引入有利于PA6中α晶的生成。