剥离型(苯乙烯/马来酸酐)共聚物/蒙脱土纳米复合材料的制备

研究了制备剥离型(苯乙烯/马来酸酐)共聚物(SMAH)蒙/脱土(MMT)纳米复合材料的方法。研究表明,通过原位插层及熔融插层只能制备出插层型的SMAH/MMT纳米复合材料。为了制备剥离型的SMAH/MMT纳米复合材料,先将尼龙6(PA6)与MMT熔融插层制备出PA6/MMT纳米复合材料,再用抽提的方法将PA6/MMT复合材料中的部分PA6除去,得到含有少量PA6的剥离型MMT,然后将剥离型MMT与SMAH共混,从而制备出剥离型的SMAH/MMT纳米复合材料。该复合材料的粘度低于SMAH,且具有较好的加工性能。     

聚对苯二甲酸丙二酯/蒙脱土复合材料的制备及性能研究

通过熔融共混法制备了聚对苯二甲酸丙二酯/蒙脱土(PTT/MMT)复合材料。采用DSC法对其非等温结晶性能进行了研究,结果表明MMT在复合材料中起到了异相成核作用,随着MMT含量的增加,PTT/MMT复合材料的结晶峰温θp向高温方向移动;采用偏光显微镜观察PTT及PTT/MMT复合材料在190℃等温结晶的情况下的球晶形态,PTT/MMT复合材料的球晶尺寸比PTT球晶尺寸大大减小;采用电子万能试验机、邵氏硬度计和D JF-20动态冲击分析仪对PTT及PTT/MMT复合材料的综合力学性能进行了测试,结果表明当MMT的质量分数为2%时的PTT/MMT复合材料的综合力学性能最佳。     

PTT/MMT纳米复合材料的研究

采用熔融共混的方法制备了聚对苯二甲酸丙二醇酯/有机蒙脱土（PTT/MMT）纳米复合材料,通过DSC、热台偏光显微镜等研究了PTT/MMT纳米复合材料的结晶行为,测定了纳米复合材料的力学性能,并用熔体流变仪研究了PTT/MMT纳米复合材料熔体流变性能。结果表明：随着PTT/MMT纳米复合材料中蒙脱上含量的增加,PTT/MMT纳米复合材料的熔融结晶温度增高,纳米复合材料的力学性能有一定的提高;PTT-蒙脱土纳米复合材料熔体的流变性能随MMT含量的增加非牛顿性减弱,熔体的粘流活化能减小。     

PTT/MMT纳米复合材料的制备及性能的研究

采用熔融共混的方法制备了聚对苯二甲酸丙二醇蘸/蒙脱土(PTT/MMT)纳米复合材料,并用红外光谱表征了PTT/MMT纳米复合材料的结构.通过DSC、热台偏光显微镜等研究了PTT/MMT纳米复合材料的结晶行为,测定了纳米复合材料的力学性能.结果表明,随着PTT/MMT纳米复合材料中蒙脱土含量的增加,PTT/MMT纳米复合材料的熔融结晶温度增高.其结晶过程为异相成核,纳米复合材料的力学性能有一定的提高.     

聚乙烯醇／蒙脱土复合材料的结构与性能研究

采用熔融插层法制备了聚乙烯醇(PVA)／蒙脱土(MMT)复合材料。通过X射线衍射仪和透射电镜对复合材料的结构进行表征，结果表明所得复合材料为剥离型或部分剥离型结构。热重测试、电子拉力试验和水溶性试验结果显示聚乙烯醇／蒙脱土纳米复合材料与纯聚乙烯醇相比，其加工热稳定性、综合力学性能以及耐水性能都得到了明显提高。     

PTT/蒙脱土复合材料非等温结晶行为的研究

采用差示扫描量热仪对熔融共混制备的聚对苯二甲酸丙二醇酯(PTT)/蒙脱土(MMT)复合材料非等温结晶行为进行了测试分析。研究结果表明:在相同的降温速率时,随着MMT含量的增加,PTT/MMT复合材料的结晶峰温向高温方向移动,结晶峰变窄,半结晶期也缩短;随着降温速率的增大,PTT/MMT复合材料的结晶峰温向低温方向移动,半结晶期变短。采用Ozawa法处理了PTT/MMT复合材料的非等温结晶过程,结果表明:MMT的加入改变了PTT的成核机理,加快了PTT的结晶速率。     

PTT/MMT复合材料流变性能的研究

采用熔融共混法制备了聚对苯二甲酸丙二酯/蒙脱土（PTT/MMT）复合材料,并采用毛细管流变仪对复合材料的流变性能进行了研究。结果表明,PTT和PTT/MMT复合材料均为假塑性流体,1 %~3 %的MMT就可以显著改善复合材料的流动性。复合材料的非牛顿指数大于PTT,表观黏度小于PTT,流动性优于PTT,可以在较低的温度下成型加工;复合材料的黏流活化能高于PTT,更适合通过升高温度的方法来改善其流动性。     

聚乙烯/纳米蒙脱土复合材料的非等温结晶行为

原位聚合法制备了不同蒙脱土含量的聚乙烯(PE)/纳米蒙脱土(MMT)复合材料.用透射电镜分析了MMT在PE基体中的分散情况,结果表明:随着MMT含量的增加,复合材料的结构从剥离型转变为剥离型和插层型混合结构.用DSC分析了PE/纳米MMT复合材料的非等温结晶行为,结果表明:复合材料的非等温结晶行为符合Avramin方程,随着MMT含量的增加,Avramin方程指数(n)减小,结晶时间(t1/2)增加.     

DDS固化EP/MMT纳米复合材料性能研究

以4,4′-二氨基二苯砜(DDS)为固化剂,制备出一种剥离型MMT/EP(蒙脱土/环氧树脂)纳米复合材料。采用红外光谱(FT-IR)法、X射线衍射(XRD)法和动态力学分析(DMA)法等对复合材料的微观结构、插层剥离行为、热性能和力学性能等进行了研究。结果表明:MMT对EP分子结构无影响,有利于EP结构和性能的设计,也便于确定其固化工艺。在无促进剂的情况下,当体系中引入5%MMT(相对于EP质量而言)时,复合材料的干态热变形温度、玻璃化转变温度(Tg)、冲击强度和拉伸强度分别提高了39℃、21℃、27.30%和10.50%;适量的MMT能有效提高纳米复合材料的耐湿热性能。     

环氧树脂/蒙脱土纳米复合材料制备及性能的研究进展

介绍蒙脱土(MMT)的性质及其有机化改性,详细阐述了环氧树脂(EP)/MMT纳米复合材料的制备方法及其性能,以及MMT在EP中的剥离机理,指出实现MMT在EP基体中完全剥离的方法仍是目前制备EP/MMT纳米复合材料的关键问题.     

Preparation and Characterization of Organically Modified Montmorillonite-Filled High Density Polyethylene/Hydroxyapatite Nanocomposites for Biomedical Applications

The study investigated the introduction of organically modified montmorillonite (MMT) in high density polyethylene/hydroxyapatite (HDPE/HA) composites for biomedical applications. The addition of HA and MMT increased the strength and stiffness of HDPE/HA composites with deterioration in impact strength and elongation at break values. XRD and TEM analysis provided evidence of exfoliated MMT layers in HDPE/HA composites and the MMT layers remained exfoliated even with further addition of HA. Simulated body fluid (SBF) analysis revealed that the size of apatite layer increased with increasing immersion time and the formation of apatite layers on the surface of composites indicates excellent biocompatibility properties.     

Novel fabrication of disorderly exfoliated sodium montmorillonite in a styrene–butadiene rubber matrix

Using industrial technologies, we prepared a sodium montmorillonite (Na‐MMT) slurry and an irradiated styrene–butadiene rubber (SBR) latex, and then spray dried them to produce a novel, ultrafine fully vulcanized powder SBR (UFPSBR)/Na‐MMT nanocompound powder in which the nanoscale UFPSBR particles and exfoliated Na‐MMT were isolated and stuck together. When the UFPSBR/Na‐MMT nanocompound powder was mixed with crude SBR, the exfoliated Na‐MMT was disorderly dispersed in the SBR matrix because of the carrier nature of the UFPSBR particle, which is compatible with SBR and disperses easily in the SBR matrix, and the SBR/UFPSBR/Na‐MMT ternary nanocomposite was prepared. When compared with SBR/Na‐MMT binary composites, the SBR/UFPSBR/Na‐MMT ternary nanocomposite has a shorter vulcanization time, higher strength, and better flame retardancy because of the good dispersion of exfoliated Na‐MMT in the SBR matrix with a Na‐MMT loading range of 4 phr. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2013     

Effect of montmorillonite on properties of styrene–butadiene–styrene copolymer modified bitumen

Clay/styrene–butadiene–styrene (SBS) modified bitumen composites were prepared by melt blending with different contents of sodium montmorillonite (Na‐MMT) and organophilic montmorillonite (OMMT). The structures of clay/SBS modified bitumen composites were characterized by XRD. The XRD results showed that Na‐MMT/SBS modified bitumen composites may form an intercalated structure, whereas the OMMT/SBS modified bitumen composites may form an exfoliated structure. Effects of MMT on physical properties, dynamic rheological behaviors, and aging properties of SBS modified bitumen were investigated. The addition of Na‐MMT and OMMT increases both the softening point and viscosity of SBS modified bitumens and the clay/SBS modified bitumens exhibited higher complex modulus, lower phase angle. The high‐temperature storage stability can also be improved by clay with a proper amount added. Furthermore, clay/SBS modified bitumen composites showed better resistance to aging than SBS modified bitumen, which was ascribed to barrier of the intercalated or exfoliated structure to oxygen, reducing efficiently the oxidation of bitumen, and the degradation of SBS. POLYM. ENG. SCI., 47:1289–1295, 2007. © 2007 Society of Plastics Engineers     

UHMWPE/MMT纳米复合材料的研制

采用复配阳离子交换剂对蒙脱土（MMT）进行有机化处理,通过固相接枝技术对超高分子量聚乙烯（UHMWPE）进行表面改性,然后采用熔融插层法制备UHMWPE／MMT纳米复合材料。XRD和SEM分析表明,MMT在UHMWPE基体中达到了纳米级分散,同时,有机MMT能较大幅度改善UHMWPE的流动性能,少量有机MMT的加入就可使UHMWPE的力学性能有所提高,     

EVOH／有机蒙脱土插层复合材料的制备与表征

将经有机化处理过的蒙脱土与EVOH熔融共混制备插层复合材料，并对该复合材料进行了XRD分析，分析结果表明：聚合物基体已经插入了有机蒙脱土片层间；复合体系中蒙脱土含量越小，蒙脱土被插开的片层间距越大；当复合体系中有机蒙脱土含量≤8％时，形成剥离型复合材料；当有机蒙脱土含量在8％～15％时，形成插层型复合材料；当有机蒙脱土含量大于15％时，复合材料中蒙脱土片层间距无明显变化。对EVOH与蒙脱土熔融共混过程的扭矩分析表明：该复合材料熔融混合9min之后，达到均匀混合和完全塑化的状态。     

WC/MMT纳米复合材料制备及其对PNP的电催化活性

以剥离后的蒙脱石(MMT)为载体,将浸渍法与原位还原技术相结合制备了碳化钨/蒙脱石(WC/MMT)纳米复合材料。采用X射线衍射、扫描电子显微镜和透射电子显微镜等手段对样品进行了表征。结果表明,剥离后蒙脱石的片层厚度为10～15 nm,层间距增大,边缘发生卷曲;复合材料由碳化钨(WC)、碳化二钨(W₂C)和蒙脱石组成,碳化钨颗粒均匀地分布于蒙脱石外表面。采用循环伏安法测试了样品对对硝基苯酚(PNP)的电化学还原性能,结果表明,WC/MMT纳米复合材料对对硝基苯酚具有良好的电催化活性,且具有较好的稳定性。蒙脱石是碳化钨基复合电催化材料良好的载体。     

Influence of the clay modification and compatibilizer on the structure and mechanical properties of ethylene–propylene–diene rubber/montmorillonite composites

Ethylene–propylene–diene rubber (EPDM)/montmorillonite (MMT) composites were prepared through a melt process, and three kinds of surfactants with different ammonium cations were used to modify MMT and affect the morphology of the composites. The morphology of the composites depended on the alkyl ammonium salt length, that is, the hydrophobicity of the organic surfactants. Organophilic montmorillonite (OMMT), modified by octadecyltrimethyl ammonium salt and distearyldimethyl ammonium salt, was intercalated and partially exfoliated in the EPDM matrix, whereas OMMT modified by hexadecyltrimethyl ammonium chloride exhibited a morphology in which OMMT existed as a common filler. Ethylene–propylene–diene rubber grafted with maleic anhydride (MAH‐g‐EPDM) was used as a compatibilizer and greatly affected the dispersion of OMMT. When OMMTs were modified by octadecyltrimethyl ammonium chloride and distearydimethyl ammonium chloride, the EPDM/OMMT/MAH‐g‐EPDM composites (100/15/5) had an exfoliated structure, and they showed good mechanical properties and high dynamic moduli. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 638–646, 2004