EVA/MMT-ODA+AUA纳米复合材料的制备与性能

采用复合插层剂十八烷基胺(ODA)和氨基十一烷酸(AUA)处理蒙脱土(MM T)。通过离子交换反应,复合插层剂进入了蒙脱土片层间,使蒙脱土片层间距增大。把该有机改性蒙脱土(MM T-ODA AUA)与EVA熔融共混,EVA分子链进入MM T-ODA AUA片层间使其间距进一步增大。EVA/MM T-ODA AUA纳米复合材料中的MM T片层与基体EVA之间的界面相互作用强,其复合材料的拉伸强度和撕裂强度比EVA有较大提高。由于纳米硅酸盐片层的阻隔作用,EVA/MM T-ODA AUA纳米复合材料的吸水率比EVA低。     

PMAA／MMT纳米复合材料的制备

采用原位插层聚合法制备聚甲基丙烯酸/蒙脱土(PMAA/MMT)纳米复合材料,探讨了引发剂用量对复合材料结构的影响。通过X射线衍射、红外光谱、固体核磁共振表征了改性蒙脱土及复合材料的结构。研究结果表明,甲基丙烯酸钠与蒙脱土具有一定的相互作用,甲基丙烯酸或甲基丙烯酸钠在蒙脱土层间聚合形成的PMAA/MMT纳米复合材料属于插层型纳米复合材料,引发剂用量对蒙脱土的层间距影响较小。     

活性炭/蒙脱土纳米复合材料的制备及吸附性能研究

以钠基蒙脱土为原料,用十六烷基三甲基溴化铵(HTMAB)制备有机蒙脱土.用自制的苯并噁嗪预聚体作插层剂,原位插层聚合制备出苯并噁嗪/蒙脱土纳米复合材料.经炭化、活化得到活性炭/有机蒙脱土纳米复合材料.经FT-IR、X射线衍射(XRD)和透射电镜(TEM)分析表明,蒙脱土片层在活性炭中已达到纳米级分散.研究其对小柴胡汤中总生物碱以及烟碱的静态吸附,试验结果表明平衡吸附数据基本符合Freundlich方程.     

超声波原位插层制备硅树脂/蒙脱土纳米复合材料

采用超声波技术,原位插层聚合法制备了甲基苯基硅树脂/有机蒙脱土(OMMT)纳米复合材料。利用X射线衍射(XRD),透射电镜(TEM)研究了复合材料内部结构以及超声波时间对蒙脱土分散性影响。结果表明,蒙脱土片层间距随着超声波时间延长而增加,当超声波时间短于20min时,有机蒙脱土片层以有序的插层型存在,形成插层型的聚合物/蒙脱土纳米复合材料(PLSN);超声波时间长于30min时,有机蒙脱土片层被剥离,无序地分散在硅树脂基体中,形成剥离型的聚合物/蒙脱土纳米复合材料。     

聚氨酯和蒙脱土协同增韧增强环氧树脂

采用聚合物互穿技术与原位插层聚合相结合的方法制备了有机蒙脱土修饰的环氧树脂/聚氨酯互穿网络纳米复合材料.傅立叶红外光谱,X射线衍射及透射电镜分析表明剥离或插层的蒙脱土片层表面羟基能与环氧树脂/聚氨酯基体发生交联反应,并且均匀分散在环氧树脂/聚氨酯基体中.力学性能测试结果表明聚氨酯,蒙脱土的加入同时增加了环氧树脂的拉伸强度和断裂韧性.扫描电镜分析表明聚氨酯和蒙脱土协同增韧增强环氧树脂的主要原因为剪切屈服和微裂纹增韧.     

乙烯基硅橡胶/改性蒙脱土纳米复合材料结构性能研究

采用机械共混原位插层法制备乙烯基硅橡胶/蒙脱土纳米复合材料,在乙烯基硅橡胶混炼和硫化过程中实现与蒙脱土的插层复合.XRD和SEM扫描分析表明,蒙脱土的层间结构发生变化,蒙脱土的层间间距由1.28m扩撑到4.90m,乙烯基硅橡胶/改性蒙脱土纳米复合材料的tanδ值在160～175℃之间显著降低,内耗下降.     

MC尼龙蒙脱土纳米复合材料的制备与表征

在超声条件下以KH550硅烷偶联剂插层蒙脱土,采用阴离子聚合反应制备MC尼龙蒙脱土纳米复合材料(MMT/PA),并对改性蒙脱土和纳米复合材料的结构进行表征与性能测试。结果表明,在超声分散条件下KH-550硅烷偶联剂进入蒙脱土的片层间,增大层间距;聚合过程中己内酰胺进入蒙脱土的片层间,实现蒙脱土与己内酰胺的键性结合,并使得最终尼龙分子插层进入蒙脱土的片层间形成纳米复合材料。蒙脱土以部分剥离的多片层聚集体均匀地分散在尼龙基体中,起到增强增韧作用,当蒙脱土含量在3%左右时纳米复合材料的力学性能达到最优。     

PA6/MMT纳米复合材料的制备与表征

采用原位聚合法制备PA6/MMT纳米复合材料。利用超薄切片法制备原子力显微镜观测样品,实现了对复合材料中纳米蒙脱土分散情况的原位观测。对复合材料进行了扫描电镜、差示扫描量热、热重、X射线衍射、单轴拉伸、缺口冲击等实验,结果表明,超薄切片法制备的PA6/MMT纳米复合材料原子力实验样品较好地实现了对纳米蒙脱土分散情况的原位观测。插层过程扩大了蒙脱土片层的间距,蒙脱土在基体中分散均匀。蒙脱土在基体中起到了异相形核作用,复合材料的结晶速率升高,热分解温度有所下降。拉伸强度与弹性模量随蒙脱土含量的增加而增加。相比于纯尼PA6,复合材料的冲击强度有不同程度的增加。     

一锅法乳液聚合制备聚苯乙烯/蒙脱土纳米复合材料

采用一锅法乳液聚合制备了聚幕乙烯／蒙脱土(PS／MMT)蚋米复合材料．一锅法即在无机蒙脱土(Na—MMT)有机化处理后,直接将乳化剂和幕乙烯单体等加入有机蒙脱土(O—MMT)悬浮液进行乳液聚合,克服了传统方法中有机蒙脱土在乳液聚合体系中不易分散的难题。XRD谱图表明,该方法成功地实现了聚苯乙烯对蒙脱土的插层．获得了良好的插层效果(蒙脱土d001面片层间距＞4nm);FT—IR表明,PS大分子链已插层进入蒙脱土片层间;DSC显示,蒙脱土的加入使聚幕乙烯的玻璃化温度Tε由原来的99．7℃提高到107．1℃;TGA表明．插层复合提高了聚幕乙烯的热稳定性。此外,由XRD谱图还初步提出了一锅法乳液聚合的插层机理。     

聚苯乙烯/粘土纳米复合材料研究进展

介绍了采用各种插层荆插层处理蒙脱土并用插层聚合、熔融插层法制备聚苯乙烯／粘土纳米复合材料及其结构特性、性能的研究进展．并对乳液聚合法制备聚苯乙烯／粘土纳米复合材料及其性能进行了简单介绍。     

浓乳液聚合方法制备聚丙烯酸酯/膨润土纳米复合材料

采用阳离子交换的方法将膨润土表面进行有机化预处理,X射线衍射的测定结果表明,膨润土的层间距由原来的1.5 nm增加到2.3 nm,并且层间距与预处理时间、温度和阳离子表面活性剂的浓度有密切关系.采用浓乳液聚合方法制备聚丙烯酸酯/膨润土纳米材料并用透射电镜对所得聚合产物进行了表征,发现聚合物中的膨润土片层分散均匀,且达到了纳米级尺寸.以所制备的聚丙烯酸酯/膨润土纳米材料为抗冲改性剂对聚氯乙烯进行抗冲改性,结果表明能极大地提高其抗冲性能.     

阳离子聚丙烯酸酯乳液纸张增强剂的制备及性能

以过硫酸钾为引发剂,壬基酚聚氧乙烯醚(OP-10)为乳化剂,醋酸乙烯酯(VAc)、丙烯酸丁酯(BA)、苯乙烯(St)、二甲基二烯丙基氯化铵(DADMAC)、丙烯酰胺(AM)为单体,在氮气的保护下通过乳液聚合制备了阳离子丙烯酸酯乳液聚合物纸张增强剂。探讨了合成过程中阳离子单体用量、乳化剂用量、引发剂用量以及反应温度对纸张增强效果的影响。同时考察了湿部应用中增强剂用量、pH值、浆种与纸张增强效果间的关系。结果发现,阳离子单体二甲基二烯丙基氯化铵用量为6%、反应温度为80℃、乳化剂用量5%和引发剂用量0.75%时,乳液聚合物的增强效果最佳。增强剂的最佳使用条件为增强剂用量0.8%,体系的pH值为7。使用增强剂时,应先调体系的pH值,再加入增强剂以充分发挥增强剂的作用。     

聚丙烯酰胺纳米复合材料的合成与溶液特性

用长链烷基季铵盐处理蒙脱土进行插层反应得到有机蒙脱土及中间相,然后与丙烯酰胺水溶液聚合,经原位插层复合反应制备聚丙烯酰胺纳米复合材料.优化聚合条件为:单体质量分数25%,氧化剂、还原剂均占单体质量分数0.08%,偶氮引发剂占单体质量分数0.05%,无机中间体含量1.0%,所得产物分子量850万.耐温抗盐实验结果表明,聚...     

Structure and melt rheology of polystyrene-based layered silicate nanocomposites

The melt-state viscoelastic properties of exfoliated in?situ polymerized and intercalated solution-blended polystyrene (PS) and organically modified montmorillonite nanocomposites were investigated and compared. The PS nanocomposites prepared by nitroxide-mediated polymerization (NMP) exhibit a stable exfoliated structure whereas the PS nanocomposites prepared by solution mixing exhibit an intercalated structure. The linear viscoelastic properties were strongly correlated with the dispersion state of the nanocomposites. On the other hand, the non-linear oscillatory shear properties exhibited shear thinning character and were consistent with the weak interactions between the polymer and the layered silicate.     

PS／OMMT纳米复合材料作为润滑油添加剂的摩擦学性能

用乳液聚合法制备了聚苯乙烯/有机蒙脱土(PS/OMMT)纳米复合材料,并利用 XRD对其结构进行表征.利用四球机考察了纳米复合材料在AN 10油中的摩擦学性能,表明所合成的PS/OMMT纳米杂化材料能提高基础油的抗磨性能及承载能力,降低其摩擦系数;复合材料中OMMT含量对摩擦学性能影响很大.EDX能谱研究结果表明,在低负荷下PS/OMMT纳米复合材料在钢球表面铺展成膜,在高负荷下,聚合物分解,裸露出纳米结构的高度分散蒙脱土片层具有高活性,能在钢球的磨斑表面成膜,改善润滑油高负荷下的摩擦学性能.     

Preparation of charged polystyrene microlatexes by emulsion polymerization induced by gamma rays

Ionic polymerizable surfactants MOBS and MOTB were synthesized and used as emulsifier to synthesize monodisperse polystyrene microlatexes by emulsion polymerization induced by gamma rays. Transmission electron microscopy and X-ray fluorescence were used to characterize the prepared polystyrene. The results show that ionic polymerizable surfactants are effective in the preparation of monodisperse polystyrene microlatexes, and that emulsion polymerization induced by gamma rays has advantages over initiator-induced emulsion polymerization. A possible nucleation stage was suggested and the kinetics of the process was also analyzed.     

添加剂对聚吡咯/氧化石墨纳米复合材料结构和性能的影响

采用单体原位聚合法制备了三种聚吡咯/氧化石墨纳米复合材料。通过XRD、FT-IR和TEM对产物进行结构表征,探讨了未加添加剂及分别以N aOH和十二烷基苯磺酸钠为添加剂制得的聚吡咯/氧化石墨纳米复合材料的结构与性能的差别。结果表明,未加添加剂和以N aOH为添加剂时产物为非晶态的剥离型聚吡咯/氧化石墨纳米复合材料;而以十二烷基苯磺酸钠为添加剂时可得到具有层状有序结构的插层型聚吡咯/氧化石墨纳米复合材料。插层型聚吡咯/氧化石墨纳米复合材料的导电和电化学性能优于剥离型聚吡咯/氧化石墨纳米复合材料,它们的提高归因于聚吡咯分子链共轭程度的增加。     

PVAc-nano-OMMT/PP-EVA复合材料的制备与性能

利用乳液聚合法引发醋酸乙烯酯(VAc)在有机蒙脱土(OMMT)中原位插层聚合, 与聚丙烯(PP)-乙烯-醋酸乙烯酯共聚物(EVA)复合体系熔融共挤制备出PVAc-nano-OMMT/PP-EVA复合材料。X射线衍射(XRD)与透射电镜(TEM)测试结果表明, 在强剪切作用下, PVAc-nano-OMMT/PP-EVA形成了剥离型纳米复合材料结构; 热失重(TGA)测试结果显示PVAc-nano-OMMT/PP-EVA的起始分解温度明显高于PP-EVA和nano-OMMT/PP-EVA, PVAc-nano-OMMT的存在使材料的热性能得以改善; 在PVAc-nano-OMMT/PP-EVA共混物中, PVAc-nano-OMMT具有明显的增韧作用; 通过氧指数(LOI)和锥形量热(CONE)测试, PVAc-nano-OMMT/PP-EVA的氧指数为24.1%, 可较大幅度地降低材料燃烧的热释放程度、 有效燃烧热和烟释放过程, 阻燃性能提高。      

Graphite oxide/poly(methyl methacrylate) nanocomposites prepared by a novel method utilizing macroazoinitiator

Graphite oxide (GO)/poly(methyl methacrylate) (PMMA) nanocomposites were prepared by a novel method utilizing macroazoinitiator (MAI). The MAI, which has a poly(ethylene oxide) (PEO) segment, was intercalated between the lamellae of GO to induce the inter-gallery polymerization of methyl methacrylate (MMA) and exfoliate the GO. The morphological, conductivity, thermal, mechanical and rheological properties of these nanocomposites were examined and compared with those of intercalated nanocomposites prepared by polymerization with the normal radical initiator, 2,2′-azobisisobutyronitrile. The improvement in conductivity by GO was more evident in exfoliated nanocomposites compared to that of intercalated nanocomposites. For example, a conductivity of 1.78 × 10⁻⁷ S/cm was attained in the exfoliated nanocomposite prepared with 2.5 parts GO per 100 parts MMA, which was about 50-fold higher than that of the intercalated nanocomposite. The thermal, mechanical and rheological properties also indicate that thin GO with a high aspect ratio is finely dispersed and effectively reinforced the PMMA matrix in both exfoliated and intercalated nanocomposites.     

Thermal stabilities of vermiculites/polystyrene (VMTs/PS) naonocomposites via in-situ bulk polymerization

Serials of vermiculites/polystyrene (VMTs/PS) nanocomposites with different contents of organo-modified vermiculites (organo-VMTs) were successfully prepared by the in-situ bulk polymerization of styrene with the organo-VMTs as macromonomers. The thermogravimetric analysis TGA results showed that the thermal stabilities of the VMTs/PS nanocomposites prepared via the bulk polymerization were better than the pure polystyrene. And the maximum thermal degradation temperature of the nanocomposites increased with the increasing of the amount of the VMTs fillers added. The polymer grafted nanoparticles had lower thermal stabilities than the pure polystyrene because of the lower molecular weight of the grafted polymers. This also showed that the crosslink reactions occurred in the grafted polystyrene chains.