Synergistic effects of organically modified montmorillonite in combination with metal oxides on the fire safety enhancement of intumescent flame-retarded epoxy resins

Synergistic effects of organically modified montmorillonite (OMMT) in combination with different metal oxides (Bi₂O₃, Sb₂O₃, and MoO₃) on the fire safety enhancement of the intumescent flame-retarded epoxy resins (EPs) were systematically evaluated. The results from X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses show that the OMMT and metal oxides acquire a uniform distribution in the EP matrix, and OMMT platelets exhibit a fully exfoliated state. The flammability and thermogravimetry (TG) tests show that the intumescent flame retardant (IFR)-OMMT-metal oxide ternary system can endow EPs with the higher synergistic efficiencies on the enhancement of flame retardancy, smoke suppression properties, and charring ability compared to those of IFR or IFR-OMMT system, and the synergistic efficiency is the following order: IFR/OMMT/Sb₂O₃ > IFR/OMMT/MoO₃ > IFR/OMMT/Bi₂O₃. In particular, the sample, filled with 1.5 wt% OMMT, 1.5 wt% Sb₂O₃, and 27 wt% IFR, passes the UL94 V-0 rating and acquires the highest limiting oxygen index value of 28.5% among the samples. The IFR-OMMT-metal oxide ternary system exerts a better synergistic effect on the generation of crosslinking and aromatic structures that supply the excellent charring effect and barrier effect for the EPs, and the synergistic efficiency of IFR-OMMT-metal oxide ternary system is varied with the types of metal oxides.     

几种丁腈橡胶/有机蒙脱土纳米复合材料的制备与对比表征

选择几种自制的有机蒙脱土,利用双辊直接混炼法与丁腈橡胶复合,测试材料的力学性能,确定出了最佳的有机蒙脱土牌号。利用透射电子显微镜观察,确定制备出了半剥离型的丁腈橡胶/有机蒙脱土（NBR/OMMT）纳米复合材料;测试材料的应力-应变曲线表征了不同有机蒙脱土含量的纳米复合材料的力学性能;利用溶剂渗透性测试实验表征了纳米复合材料的耐油性提高;通过透射电子显微镜观察发现,采用有机蒙脱土预凝胶,成功地制备了全剥离型的NBR/OMMT纳米复合材料。     

OMMT/IIR纳米复合材料结构与性能的研究

采用熔体插层法制备有机蒙脱土(OMMT)／IIR纳米复合材料。试验结果表明，OMMT／IIR纳米复合材料是插层型纳米复合材料；与无机粘土／IIR微米复合材料及IIR相比，OMMT／HR纳米复合材料具有良好的物理性能，且其物理性能均随OMMT用量的增大而明显提高；与IIR相比，OMMT／HR纳米复合材料具有优异的气密性。     

有机蒙脱土增强聚氯乙烯手套材料的制备与表征

通过在乳液聚氯乙烯（PVC）中添加有机蒙脱土（OMMT）来研究OMMT对其各项性能的影响。结果表明：OMMT对乳液PVC／邻苯二甲酸二辛酯（DOP）／OMMT纳米复合材料的力学性能有一定的改善效果;对复合材料的抗增塑剂迁移效果明显;在耐酸和耐碱试验中,未添加OMMT的复合材料的拉伸强度和撕裂强度分别降低了7．3％、5．i％和5．5％、13．3％,而添加3份OMMT后,仅仅降低了2．5％、2．6％和1．5％、4．2％,效果显著。     

PBA/OMMT制备及其对PA6力学性能的影响

用十二烷基磺酸钠(SDS)将Na基蒙脱土(MMT)改性成有机蒙脱土(OMMT),采用原位聚合法制备了聚丙烯酸丁酯(PBA)/OMMT,并将其按适当比例添加到尼龙6(PA6)中。通过红外光谱仪、差示扫描量热仪等表征了OMMT、PBA/OMMT的结构,并检测了PA6/PBA/OMMT复合材料的力学性能。结果表明:添加5%的PBA/OMMT后,PA6/PBA/OMMT复合材料的拉伸强度提高了23.1%,缺口冲击强度的降低幅度有所减缓。     

Joint Effect of Compatibilizer and Organo-Montmorillonite on Compatibilization of Polyamide-6/Poly(phenylene oxide) Blend: Morphology and Properties

Compatibilizer (styrene–maleic anhydride copolymer, SMA) and organo-montmorillonite (OMMT) were introduced into immiscible polyamide-6 (PA6)/ poly(phenylene oxide) (PPO) blend to obtain quaternary nanocomposites simply by melt extrusion. OMMT tactoids formed in PA6/PPO/OMMT ternary blend would become smaller or disappear with the addition of SMA. Besides, viscosity of SMA compatibilized PA6/PPO blend decreased a lot with the addition of OMMT. Based on these results, a mechanism for joint effect of SMA and OMMT in compatibilizing PA6 and PPO was proposed. We further studied water absorption and tensile properties of the nanocomposites, which were in consistent with the proposed mechanism.     

炭黑/蒙脱土并用对 HNBR复合材料性能的影响

为提高HNBR/OMMT纳米复合材料的性能,在分析螺杆泵定子橡胶实际破坏形式的基础上,结合各种检测手段研究炭黑的最佳加入份数以及炭黑/蒙脱土材料并用的效果.结果表明:炭黑N330用量对材料的硫化时间影响较小,但能显著提高门尼粘度和邵氏硬度;对HNBR/OMMT复合材料的机械性能、阿克隆磨耗性能及耐原油介质老化等性能进行...     

SMC/BMC用不饱和聚酯提高玻纤浸润的改性与研究

采用与玻纤具有良好亲和性的有机蒙脱土/气相白炭黑(OMMT/SiO2)改性不饱和聚酯,通过XRD、FTIR、接触角和力学性能,研究了改性不饱和聚酯的微观结构和主要性能.研究结果表明,随着OMMT/SiO2的加入,树脂与玻纤接触角变小,改性不饱和聚酯与玻纤的浸润性增强.物理性能测试表明,当OMMT/SiO2含量为4%时,不饱和聚酯浇铸体冲击强度可提高50%,弯曲强度下降低于15%.     

Mechanical and rheological properties of PP/SEBS/OMMT ternary composites

The microstructure and mechanical properties of polypropylene (PP)/OMMT binary nanocomposites and PP/styrene‐6‐(ethylene‐co‐butylenes)‐6‐styrene triblock copolymer (SEBS)/OMMT ternary nanocomposites were investigated using X‐ray diffraction (XRD), transmission electron microscopy (TEM), and rheology and electromechanical testing machine. The results show that the organoclay layers are mainly intercalated and partially exfoliated in the PP‐based nanocomposites. The additions of SEBS and OMMT have no significant effect on the crystallization behavior of PP. At the same time, it can be concluded that the polymer chains of PP and SEBS have intercalated into the organoclay layers and increase the gallery distance after blending process based on the analytical results from TEM, XRD, and rheology, which result in the form of a percolated nanostructure in the PP‐based nanocomposites. The results of mechanical properties show that SEBS filler greatly improve the notched impact strength of PP, but with the sacrifice of strength and stiffness. OMMT can improve the strength and stiffness of PP and slightly enhance the notched impact strength of PP/PP‐g‐MA. In comparison with neat PP, PP/OMMT, and PP/SEBS binary composites, notched impact toughness of the PP/SEBS/OMMT ternary composites significantly increase. Moreover, the stiffness and strength of PP/SEBS/OMMT ternary nanocomposites are slightly enhanced when compared with neat PP. It is believed that the synergistic effect of both SEBS elastomer and OMMT nanoparticles account for the balanced mechanical performance of the ternary nanocomposites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of functionalized SWCNTs on microstructure of PP‐g‐MA/OMMT/f‐SWCNTs nanocomposite

The aim of this work was to study the effect of functionalized single‐walled carbon nanotubes (f‐SWCNTs) on the microstructure of PP‐g‐MA/organic modified montmorillonite (OMMT)/f‐SWCNTs ternary nanocomposite. Pristine SWCNTs were chemically modified by maleic anhydride to improve the interaction between PP‐g‐MA and nanotubes. The dispersion states of OMMT in the different nanocomposites were investigated by wide angle X‐ray diffraction. The morphologies of the nanocomposites were characterized by scanning electron microscopy. Crystallization behaviors of nanocomposites were studied through differential scanning calorimetry and polarizing optical microscopy. Different than the PP‐g‐MA/OMMT binary nanocomposite, in which the OMMT is mainly in an exfoliated state, the ternary PP‐g‐MA/OMMT/f‐SWCNTs nanocomposite exhibits mostly intercalated OMMT. Furthermore, in the ternary nanocomposite, the crystallization of polymer is mainly induced by f‐SWCNTs rather than by OMMT. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009