用乳液插层法制备丙烯酸丁酯/有机蒙脱土纳米复合材料

用乳液插层法制备了丙烯酸丁酯/有机蒙脱土纳米复合材料。先将钠基蒙脱土有机化,然后用乳液聚合法反应制得纳米复合材料。X射线衍射分析表明,蒙脱土有机化后层间距增大,季铵盐插层进入蒙脱土层间,乳液聚合后层间距进一步增大,聚丙烯酸丁酯插层到蒙脱土层间,得到丙烯酸丁酯/有机蒙脱土纳米复合材料。动态力学分析表明,复合材料的储能模量大大提高,损耗因子几乎不变。     

有机蒙脱土改性PC/ABS合金材料的力学性能研究

以有机蒙脱土、相容剂为改性材料,采用熔融插层法制备了有机蒙脱土/聚碳酸酯(PC)/丙烯腈-苯乙烯-丁二烯共聚物(ABS)复合材料,研究了增容剂用量、有机蒙脱土用量对复合材料力学性能的影响。结果表明:相容剂和有机蒙脱土的加入不仅使PC/ABS合金材料的韧性显著增加,而且其刚性也有所增强。     

苯乙烯-丙烯酸丁酯／蒙脱土纳米复合涂料的研究

采用乳液插层聚合法合成苯乙烯-丙烯酸丁酯/蒙脱土(MMT)纳米复合阻燃涂料,对涂膜的机械性能和阻燃性进行了研究,结果表明:纳米插层复合阻燃涂料不但能增加涂膜的机械性能,而且还能提高涂膜的阻燃性.     

表面活性剂和硅烷偶联剂有机复合改性蒙脱土的制备及性能表征

为增加蒙脱土与有机物的相容性,采用十六烷基三甲基溴化铵(CTAB)与硅烷偶联剂(KH-560)对蒙脱土进行了有机复合改性。X-射线衍射和红外光谱的结果表明,CTAB已插入蒙脱土片层,平均层间距离从1.54 nm增大到3.98 nm和2.08 nm,而KH-560未插入蒙脱土片层,只是覆盖在蒙脱土表面,未改变蒙脱土的插层结构;分散性实验表明,表面活性剂和硅烷偶联剂有机复合改性的蒙脱土在苯乙烯、液体石蜡中的分散性好于其他改性蒙脱土;有机复合改性不仅增大了蒙脱土层间距,且改善了蒙脱土与聚氯乙烯的界面效果,提高了蒙脱土在聚氯乙烯基体中的分散均匀性,从而使聚氯乙烯/蒙脱土复合材料玻璃化转变温度的提高和力学性能的改善更明显。     

有机插层剂对聚酰胺6／MMT纳米复合材料制备的影响研究

以烷基胺、季铵盐和氨基酸作为有机插层剂与蒙脱土片层进行阳离子交换，制备出层间距不同的有机蒙脱土。采用熔融插层法和原位聚合法分别制备聚酰胺（R％）／蒙脱土（MMT）纳米复合材料，并利用XRD、FT-IR、TEM对有机蒙脱土及纳米复合材料进行结构表征。研究结果表明：用烷基胺、季铵盐和氨基酸有机插层剂改性的蒙脱土层间距由原来的1．25nm分别增大到3．21nm、3．99nm和1．82m；季铵盐有机插层剂更适用于熔融插层法制备PA6／MMT纳米复合材料，而氨基酸有机插层剂更适用于原位聚合法制备PA6／MMT纳米复合材料。     

季铵盐插层钠基蒙脱土的工艺研究

采用溴化十六碳烷基三甲铵对钠基蒙脱土进行改性,研究了反应温度、反应配比、反应时间和搅拌方式对蒙脱土插层效果的影响。FTIR证明有机插层剂已进入蒙脱土的层间;XRD结果表明蒙脱土的层间距由1．4nm增加到2．8～3．9nm;TEM观察表明蒙脱土的层间距增大。     

SBS/蒙脱土复合材料的制备及其性能Ⅱ.复合材料的性能

分别采用大分子溶液插层法和大分子熔融插层法制备了苯乙烯-丁二烯-苯乙烯共聚物（SBS）／蒙脱土纳米复合材料．研究了材料的力学性能。纳米结构的形成对复合材料的性能产生显著影响,少量蒙脱士的引入可以明显改善SBS／蒙脱土复合材料的力学性能。无论溶液插层法制备的星型SBS／蒙脱土纳米复合材料,还是熔融插层法制备的线型SBS／蒙脱土纳米复合材料,其拉伸强度和断裂伸长率都同时增加。其中,溶液插层法制备的纳米复合材料的拉伸强度和断裂伸长率分别较纯SBS增加了75％和55％;熔融法制备的纳米复合材料的托伸强度和断裂伸长率分别较纯SBS增加了70％和18％。     

乳液法有机蒙脱土/SBR纳米复合技术的改进

对现有大分子乳液插层法制备蒙脱土 /SBR纳米复合材料技术进行改进。试验结果表明 ,使用低分子醇类混合物预分散有机蒙脱土 ,可使疏水的有机蒙脱土直接用于乳液插层法制备有机蒙脱土 /SBR纳米复合材料 ;在SBR胶乳中加入少量带羟基的聚合物水溶液 ,能够使有机蒙脱土层间距扩大 ,有利于提高插层动力 ;超声波对聚合物插层没有明显的强化作用     

有机改性蒙脱土制备聚酰胺6/蒙脱土复合材料

采用有机复合改性的方法制备了改性蒙脱土,并采用原位聚合方法制备了尼龙-6/蒙脱土复合材料,利用FTIR、TG-DTA、XRD对有机蒙脱土进行了表征。结果表明,有机插层剂已进入蒙脱土的层间,使蒙脱土的层间距由原来的1.39 nm增大到2.32 nm,从而改善了它的分散性以及与尼龙-6之间的粘结作用,二者构成的纳米复合材料具有很好的力学性能。当加入2%的有机蒙脱土时,拉伸强度提高16%,冲击强度提高5%。     

紫外辐照对EVOH／蒙脱土纳米复合材料性能影响的研究

对蒙脱土进行有机改性,并对改性蒙脱土进行红外(FT-IR)、X射线(XRD)、扫描电镜(SEM)表征;同时采用溶液插层法制备了乙烯-乙烯醇共聚物(EVOH)/蒙脱土纳米复合膜,并对其进行不等时间的紫外辐照处理.结果表明:改性后的蒙脱土表面由亲水变为疏水;层距南1.467 nm增大到3.5 nm;而经紫外辐照处理的复合膜的力学性能、阻隔性能得到了较好的提高,同时复合膜的透明性没受到影响.     

聚合物/有机蒙脱土纳米复合材料分散形态的制备影响因素

选择不同种类的有机蒙脱土（OMMT）和不同聚合物种类,采用不同加工条件和工艺,利用机械混炼法或挤出法制备出了不同亚微观形态的聚合物/有机蒙脱土纳米复合材料。首先通过研究具有不同的改性层间距的OMMT,发现改性后层间距的增大有利于聚合物分子的插层及蒙脱土片层的剥离,有利于制备剥离型纳米复合材料,并用示意图简要说明了形成过程;而同一种OMMT在具有不同分子结构的聚合物中,利用实例（高密度、低密度、线型低密度聚乙烯）以及简易示意图说明了聚合物分子链结构对于制备的纳米复合材料的亚微观形态的影响机理。在加工工艺条件中,加工过程中的剪切力大小是主要影响因素,通过以挤出法和机械混炼法制备的PP/OMMT与EPDM/OMMT纳米复合材料的TEM结果对比分析,说明剪切力的增大有利于蒙脱土片层的分离,更倾向于制备出剥离型纳米复合材料。     

Prepared hydrogenated nitrile rubber (HNBR)/organo–montmorillonite nanocomposites by the melt intercalation method

The polymer, Hydrogenated Nitrile‐Butadiene Rubber (HNBR) was melt compounded with organophilic montmorillonite (OMMT). The dispersion of the OMMT in the HNBR matrix was characterized by X‐ray diffraction (XRD), which indicated that at the temperature of 100°C, the organoclay belong to the exfoliated and interlayer structure. The effect of sulfur on the dispersion of OMMT in the polymer matrix was also studied. The vulcanization changed the dispersion of OMMT in polymer matrix greatly and the basal spacing of clay layers is decreased after vulcanization. The mechanical properties, Akron abrasion and the crude oil medium aging‐resistant of HNBR nanocomposites were examined as a function of the OMMT content in the matrix of polymer. The results of the test show remarkable improvement in tensile strength, tear strength, aging‐resistant, and hardness of HNBR nanocomposites than that of unfilled HNBR. It is obvious that the 10 phr of OMMT filled nanocomposites have the best mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Graft copolymerization of sodium acrylate onto organophilic montmorillonites initiated by potassium diperiodatonickelate (IV) and application of graft copolymer in water‐superabsorbent

The graft copolymerization of sodium acrylate (SA) onto organophilic montmorillonites (OMMT) initiated by redox reaction of potassium diperiodatonickelate (IV) [Ni(IV)] with reactive groups on OMMT substrate was studied in alkaline medium. The grafting parameters have been investigated as a function of the ratio of monomer to OMMT, the concentration of initiator, temperature, and pH value. The structure of the graft copolymer (OMMT‐g‐PSA) was systematically characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscope (SEM). It was found that [Ni(IV)] belongs to a highly efficient initiator for graft copolymerization of SA onto OMMT via the redox iniation (grafting efficiency > 95%). Furthermore, the experimental results also showed that the graft copolymer gels synthesized under optimal condition exhibited a maximum water absorbency of 1104 g/g in distilled water and 111 g/g in 0.2 wt % NaCl solution, respectively, and its water retention ability is more than 91% after centrifugal separation for 2 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation of Cu/OMMT/LLDPE nanocomposites and synergistic effect study of two different nano materials in polymer matrix

Cu/OMMT (organo-montmorillonite)/LLDPE (linear low-density polyethylene) nanocomposites were prepared via melt mixing combined with melt extruding process. X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectra, scanning electron microscope (SEM), and transmission electron microscopy (TEM) were employed to characterize the resultant nanocomposites. The results showed that the OMMT layers were exfoliated and the nano-Cu particles were distributed uniformly in the polymer matrix. And the introduction of nanofiller into LLDPE matrix had little effect on the crystallinity of the polymer. The salt spray tests showed that OMMT and nano-Cu could improve the anticorrosion properties of LLDPE matrix, respectively. And the coexistence of OMMT and nano-Cu in Cu/OMMT/LLDPE nanocomposites could produce a synergistic effect on enhancing the anticorrosion properties. Furthermore, the co-incorporation of OMMT and nano-Cu into the polymer matrix also increased the thermal-oxidative stability and mechanical properties of LLDPE matrix significantly, as compared with the Cu/LLDPE and OMMT/LLDPE nanocomposites due to the synergistic effect. The bactericidal properties evaluation showed that the bactericidal ability of Cu/OMMT/LLDPE increases with nano-Cu content effectively.     

有机蒙脱土对PA6/PP合金体系的作用机制及其对材料性能的影响

研究了有机蒙脱土对PA6/PP合金体系的作用机制及其对材料性能的影响。结果表明,OMMT的添加可以提高体系的拉伸强度、弯曲强度和弯曲模量,但冲击强度会有某种程度的下降;OMMT主要分散在PA6连续相中,且当其添加量质量份数低于5%时,可以在PA6相中实现较充分的剥离;OMMT对PA6/PP合金体系有着显著的增容作用,这可能和片层对PP分散相凝聚时的阻隔,以及片层所起到的类似接枝物的增容作用有关;OMMT在PA6基体中被充分剥离后,将有利于使复合体系的拉伸强度、弯曲强度得到提高,但OMMT片层及和片层有关的类似接枝物的存在,将束缚并限制界面层附近PP相的屈服,而使材料冲击韧性下降。     

PVC/PA1212/OMMT纳米复合材料的结构与性能

采用熔融插层法制备了聚氯乙烯(PVC)/聚酰胺1212(PA1212)/有机蒙脱土(OMMT)纳米复合材料,通过X射线衍射、透射电镜、扫描电镜等分析方法研究了OMMT在聚合物基体中的分布及其对PVC/PA1212复合材料分散相形态和力学性能的影响。结果表明:OMMT以剥离态选择性分布于PA1212相中;OMMT在PVC/PA1212复合材料中起到了细化PA1212的作用,促使PA1212分散更加均匀;适量OMMT的加入提高了PVC/PA1212复合材料的力学性能。     

Solid‐state mechanical properties of polypropylene/nylon 6/clay nanocomposites

The mechanical and thermomechanical properties as well as microstructures of polypropylene/nylon 6/clay nanocomposites prepared by varying the loading of PP‐MA compatibilizer and organoclay (OMMT) were investigated. The compatibilizer PP‐MA was used to improve the adhesion between the phases of polymers and the dispersion of OMMT in polymer matrix. Improvement of interfacial adhesion between the PP and PA6 phases occurred after the addition of PP‐MA as confirmed by SEM micrographs. Moreover, as shown by the DSC thermograms and XRD results, the degree of crystallinity of PA6 decreased in the presence of PP‐MA. The presence of OMMT increased the tensile modulus as a function of OMMT loading due to the good dispersion of OMMT in the matrix. The insertion of polymer chains between clay platelets was verified by both XRD and TEM techniques. The viscosity of the nanocomposites decreased as PP‐MA loading increased due to the change in sizes of PA6 dispersed phase, and the viscosity increased as OMMT loading increased due to the interaction between the clay platelets and polymer chains. The clay platelets were located at the interface between PP and PA6 as confirmed by both SEM and TEM. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

OMMT/ZDMA协同增强HNBR复合材料的性能研究

以离子聚合物(ZDMA)、有机蒙脱土作补强剂,采用机械混炼法制备了氢化丁腈橡胶/有机蒙脱土纳米复合材料,研究了OMMT/ZDMA协同作用对氢化丁腈橡胶纳米复合材料性能的影响,并使用扫描电镜(SEM)、热失重分析(TG)、差示扫描量热分析(DSC)及力学性能测试等方法分析了复合材料的结构和性能。结果表明,有机蒙脱土用量较少可达到纳米级分散,材料力学性能得到相应改善;用量较大时,OMMT团聚几率增大,可能形成应力集中点,影响复合材料力学性能。热性能分析表明,加入有机蒙脱土在一定程度上提高了HNBR的热稳定性。     

Studies on the viscoelasticity of poly(trimethylene terephthalate)/poly(ethylene–octene)/organomontmorillonite nanocomposites

The viscoelasticity of poly(trimethylene terephthalate)/maleinized poly(octene‐ethylene) copolymer/organomontmorillonite (OMMT) nanocomposites were investigated at both liquid and glassy states by using the rotational rheometer and dynamic mechanical analysis, respectively. The viscoelasticity results suggest that OMMT has many important influences on the structure, modulus, toughness, and cold‐crystallization of the nanocomposites. The OMMT has a strip‐like sheet morphology in the polymer matrix and when OMMT content increases to 4 wt%, the physical network‐like structure begins to form in the nanocomposites. The pseudoplasticity of the melts is increased by OMMT. In addition, the complex viscosity, storage modulus, and viscous behavior of the melts are increased with increasing OMMT content. The creep resistance of the nanocomposites is improved by OMMT, and it plays an important role on reinforcing the melts. The stress relaxation of the melts suggests that the nanofillers can not only enhance the interfacial interactions of the nanocomposites but also inhibit the recovery of the polymer chain segments. At glassy state, the nanocomposites' storage modulus increases with increasing OMMT content. As glass transition occurs, the loss factor and loss modulus suggest that OMMT toughens the polymer matrix. At rubber‐elastic state, OMMT depresses the cold‐crystallization of the polymer matrix due to its limitation effect on the motion of molecular chains. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Cellulose nanocrystals-organic montmorillonite nanohybrid material by electrostatic self-assembly

The hybridization based on various nanoparticles is an emerging technological field, involving the synergistic hybrid assembly of nanoparticles. In order to broaden the application of existing nanomaterials such as cellulose nanocrystals (CNC) and montmorillonite (MMT), a novel CNC–organic MMT (OMMT) nanohybrid material was constructed by electrostatic self-assembly. Morphology observations showed that one-dimensional needle-like CNC were adsorbed on the surface of two-dimensional flake-like OMMT, thereby forming a three-dimensional nanohybrid. In the nanohybrid, CNC and OMMT still maintained their original chemical structures. Zeta potential results indicated that there was a strong electrostatic adsorption between CNC and OMMT. Based on this, the lamellar structure of OMMT can hide sulfate groups on the CNC surface and had a shielding effect on heat transfer, thereby evidently improving the thermal stability of the nanohybrid. The nanohybrid with unique nanostructure is expected to achieve synergistic effects in polymer nanocomposites, which may provide a promising strategy for the fabrication of high-performance polymer nanocomposites.