Preparation and investigation of ethylene–vinyl acetate copolymer/silicone rubber/clay nanocomposites

In this article, the combination of silicone rubber (SR) elastomer with synthetic iron montmorillonite (Fe‐MMT) to form a kind of new flame‐retardant system based on an ethylene–vinyl acetate (EVA) copolymer is first reported. Also, the flame retardancy of the EVA/SR/Fe‐MMT hybrid are compared with that of EVA/SR/natural sodium montmorillonite. The structures of the nanocomposites were characterized with X‐ray diffraction and transmission electron microscopy. Cone calorimeter tests and thermogravimetric analysis were used to evaluate the flame‐retardant properties and thermal stability of the composites, respectively. In addition, tensile tests were carried out with a universal testing machine, and the morphology of the fracture surface was observed with environmental scanning electron microscopy. We found that SR/organophilic montmorillonite (Fe‐OMT) was more effective in reducing the primary peak heat release rate of the nanocomposite, and the EVA/SR/Fe‐OMT hybrid had a higher thermal stability in the deacetylated polymer than EVA/SR/sodium organophilic montmorillonite. Moreover, the exfoliated EVA/SR/Fe‐OMT nanocomposite displayed excellent mechanical properties because of a better dispersion of Fe‐OMT in the polymer matrix, and a possible mechanism is discussed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Influence of organophilic clay and preparation methods on EVA/montmorillonite nanocomposites

Ethylene‐vinyl acetate copolymer (EVA)/montmorillonite MMT nanocomposites have been prepared by using different methods: one is from the organophilic montmorillonite (OMT) and the other is from the pristine MMT and reactive compatibilizer hexadecyl trimethyl ammonium bromide (C16). In this study, different kneaders were used (twin‐screw extruder and twin‐roll mill) to prepare nanocomposites. The nanocomposite structures are evidenced by the X‐ray diffraction (XRD) and high‐resolution electronic microscope (HREM). The thermal properties of the nanocomposites were investigated by thermogravimetric analysis (TGA). Moreover, the tensile tests were carried out with a Universal testing machine DCS‐5000. It is shown that different methods and organophilic montmorillonite have influence on EVA/MMT nanocomposites.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2416–2421, 2004     

ABS／PVC共混改性的研究

考察了PVC含量对ABS/PVC共混体系性能的影响。为了进一步提高共混体系的性能，在体系中分别加入CPE、MBS做为第三组分。通过性能比较，发现MBS可有效提高共混体系的综合性能。为了增加共混体系的阻燃性能，加入助阻燃剂Sb2O3，结果表明共混体系的阻燃性能有了很大提高。     

低烟阻燃ABS专用料的研制

研究了十溴联苯醚/四溴双酚A/三氧化二锑复合阻燃体系、氢氧化镁/硼酸锌/三氧化钼复合抑烟体系对(丙烯腈/丁二烯/苯乙烯)共聚物(ABS)的阻燃、抑烟作用,以及增韧剂对低烟阻燃体系的增韧效果,制备了低烟阻燃ABS专用料。测试结果表明,该专用料抑烟、阻燃性能及综合力学性能良好,可满足家电、汽车等对低烟阻燃ABS专用料的要求。     

Mechanical properties,flame retardancy,and smoke suppression of lanthanum organic montmorillonite/poly(vinyl chloride) nanocomposites

A dimethyl dioctadecyl ammonium chloride modified organic montmorillonite (OMMT_‐I.44P)/poly(vinyl chloride) (PVC) nanocomposite and anionic‐surfactant‐modified lanthanum organic montmorillonite (La‐OMMT)/PVC nanocomposites (with three different anionic surfactants for the La‐OMMTs) were prepared via melt‐intercalation technology. The effects of the La‐OMMTs and OMMT_‐I.44P on the mechanical properties, flame retardancy, and smoke suppression of PVC were studied. X‐ray diffraction characterization showed that the La‐OMMTs were exfoliated in the PVC matrix. The mechanical properties of the nanocomposites were enhanced by the incorporation of the La‐OMMTs. Cone calorimetry and gas chromatography–mass spectrometry analyses indicated that the incorporation of the La‐OMMTs enhanced the flame retardancy and smoke suppression of the PVC nanocomposites. Scanning electron microscopy photos further showed that the residual char surfaces of La‐OMMT/PVC were all intact and, thus, provided better barriers to energy and smoke transport. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43951.     

HIPS/纳米蒙脱土复合材料的研究

添加不同种类，不同数量的纳米蒙脱土，混炼制得HIPS／纳米蒙脱土复合材料，以改善高抗冲聚苯乙烯（HIPS）的性能，测试了其力学性能，热稳定性性。结果表明，添加3％烘干的蒙脱土Cloisite 30A的HIPS／纳米蒙脱土复合材料具有较好的综合力学性能，可作为工程塑料使用；HIPS／纳米蒙脱土复合材料的热稳定性与阻燃性有所改善，添加5％烘干的蒙脱土Cloisite 15A的HIPS／纳米蒙脱土复合材料具有较好的阻燃性。     

The catalyzing carbonization properties of acrylonitrile-butadiene-styrene copolymer (ABS)/rare earth oxide (La<Subscript>2</Subscript>O<Subscript>3</Subscript>)/organophilic montmorillonite(OMT) nanocomposites

The catalyzing carbonization properties of acrylonitrile-butadiene-styrene copolymer (ABS) /rare earth oxide (La₂O₃) /organophilic montmorillonite(OMT) nanocomposites have been studied. X-ray diffraction (XRD), transmission electron microscopy (TEM),thermogravimetric analyses (TGA), laser raman spectroscopy (LSR) and high-resolution electron microscopy (HRTEM) are used to characterize the morphology and properties of the nanocomposites. The results show that intercalated nanocomposites have formed no matter with or without La₂O₃, and nanocomposites have better thermal stability with high charred residue, especially at the presence of La₂O_3. With the addition of 3wt%La₂O₃, the char residue yield of ABS/5wt% OMT can be up to 12.6wt% in comparison to 2.4wt% of pure ABS. The LSR and HRTEM are carried out to investigate the structure of the purified char residue of ABS/5wt%OMT/3wt%La₂O₃, and demonstrate the formation of the graphite structure. The possible catalyzing carbonization mechanism is discussed in this paper.     

Effect of order of mixing on morphology and thermal properties of the compatibilized PBT and ABS alloys/OMT nanocomposites

Poly(butylene terephthalate) (PBT) and acrylonitrile–butadiene–styrene terpolymers (ABS) alloys/organically modified montmorillonite (OMT) nanocomposites using terpolymers of random ethylene, methyl acrylate, and glycidyl methacrylate as the reactive compatibilizer were prepared by different melt‐mixing sequences. The microstructures were characterized by scanning electron microscopy, X‐ray diffraction, transmission electron microscopy, and high‐resolution electron microscopy. It was found that order of mixing affects the dispersion state of OMT in the alloy matrix. The crystallization behavior of PBT in the compatibilized PBT and ABS alloys/OMT nanocomposites was studied by wide angle X‐ray diffraction. It revealed that order of mixing has influence on the preferential crystal growing direction of PBT owing to the antagonistic effect of ABS and OMT. Thermogravimetric analyses and differential scanning calorimetry also showed order of mixing changes the thermal property of the compatibilized PBT and ABS alloys/OMT nanocomposites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2130–2139, 2007     

羟基锡酸锌包覆纳米氢氧化镁在PVC中的应用

通过均匀沉淀法制备了羟基锡酸锌包覆纳米氢氧化镁并将其应用到聚氯乙烯(PVC)中。利用XRD、TG、DTA对羟基锡酸锌包覆纳米氢氧化镁的性能进行了研究,并通过氧指数、烟密度研究了羟基锡酸锌包覆纳米氢氧化镁对PVC的阻燃和抑烟性能的影响,同时对其力学性能也进行了研究。结果表明:纳米氢氧化镁表面均匀地包覆了羟基锡酸锌;羟基锡酸锌包覆纳米氢氧化镁对PVC的阻燃和抑烟性能明显优于单独添加羟基锡酸锌、纳米氢氧化镁以及羟基锡酸锌包覆微米氢氧化镁和羟基锡酸锌与纳米氢氧化镁混和物时的阻燃、抑烟性能;纳米材料的加入对PVC的力学性能也产生了有利的影响。     

PVC/montmorillonite nanocomposites based on a thermally stable,rigid‐rod aromatic amine modifier

Two kinds of polyvinyl chloride (PVC)/montmorillonite (MMT) nanocomposites were prepared by the melt intercalation method based on a thermally stable, rigid‐rod aromatic amine modifier and a commonly used 1‐hexadecylamine. The information on morphological structure of PVC/MMT nanocomposites was obtained using XRD and TEM. The mechanical, thermal, and flame retardant properties of the nanocomposites were characterized by universal tester, DMA, TGA, and cone calorimeter. The degree of degradation of PVC was studied by ¹H‐NMR. MMT treated by the aromatic amine exhibited better dispersibility than that treated by 1‐hexadecylamine. The nanocomposites, based on this MMT, consequently exhibited better mechanical, thermal, and flame retardant properties and lower degradation degree than those based on 1‐hexadecylamine‐treated MMT. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 567–575, 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     

Flammability and thermal stability studies of ABS/Montmorillonite nanocomposite

Acrylonitrile–butadiene–styrene (ABS)/montmorillonite nanocomposites have been prepared using a direct melt intercalation technique by blending ABS and organophilic clay of two different particle sizes: OMTa (5 µm) and OMTb (38 µm). Their structure and flammability properties were characterized by X‐ray diffraction, high resolution electronic microscopy (HREM), thermogravimetric analysis (TGA) and cone calorimeter experiments. The results of HREM showed that ABS/5 wt% OMTa nanocomposite was a kind of intercalated–delaminated structure, while ABS/5 wt% OMTb nanocomposite was mainly an intercalated structure. The nanocomposites showed a lower heat release rate peak and higher thermal stability than the original ABS by TGA and cone calorimeter experiments. Also, the intercalated nanocomposite was more effective than an exfoliated–intercalated nanocomposite in fire retardancy. Copyright © 2003 Society of Chemical Industry     

Morphology,mechanical properties,and thermal stability of rigid PVC/clay nanocomposites

PVC/Poly(ε‐caprolactone) (PCL)/organophilic‐montmorillonite (OMMT) and PVC/Polylactide (PLA)/OMMT nanocomposites were prepared by a two‐step process. PCL/OMMT and PLA/OMMT master batches were prepared by melt blending using a two‐roller mill first, and then they were blended with PVC via extrusion. PVC/OMMT nanocomposites were also prepared using a two‐roller mill. Morphology, mechanical properties, and thermal stability were investigated. The formation of exfoliated or intercalated nanocomposites was confirmed by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). Only the PVC/PCL/OMMT nanocomposite showed both higher tensile strength and stiffness than unfilled PVC. Atomic force microscopy (AFM) indicated dependency of this behavior not only on the clay dispersion, but also on the adhesion between the OMMT and the polymer matrix. Furthermore, scanning electron microscopy (SEM) showed that the large plastic deformation of the PVC/PCL matrix also contributed to the strength increase of the PVC nanocomposites. The effect of PCL/OMMT on the improvement of the thermal stability of PVC was remarkable while the effect of PLA/OMMT was moderate. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.     

Compatibilizing effect of maleated polypropylene on the mechanical properties and morphology of injection molded polyamide 6/polypropylene/organoclay nanocomposites

Polyamide 6/polypropylene (PA6/PP=70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic modified montmorillonite (organoclay) were prepared using twin screw extruder followed by injection molding. Maleated polypropylene (MAH-g-PP) was used to compatibilize the blend system. The mechanical properties of PA6/PP nanocomposites were studied through tensile and flexural tests. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to assess the fracture surface morphology and the dispersion of the organoclay, respectively. X-ray diffraction (XRD) was used to characterize the formation of nanocomposites. The thermal properties were characterized by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The dynamic mechanical properties of PA6/PP nanocomposites were analyzed by using dynamic mechanical thermal analyzer (DMTA). The strength and stiffness of PA6/PP nanocomposites were improved significantly in the presence of MAH-g-PP. This has been attributed to the synergistic effect of organoclay and MAH-g-PP. The MAH-g-PP compatibilized PA6/PP nanocomposites showed a homogeneous morphology supporting the compatibility improvement between PA6, PP and organoclay. TEM and XRD results revealed the formation of nanocomposites as the organoclay was intercalated and exfoliated. A possible chemical interaction between PA6, PP, organophilic modified montmorillonite and MAH-g-PP was proposed based on the experimental work.     

聚氯乙烯/丙烯腈-丁二烯-苯乙烯共聚物共混体系的研究

以国产聚氯乙烯、丙烯腈 丁二烯 苯乙烯共聚物为主要原料,配以合适助剂,在研究了PVC ABS共混体系的相容性、流变特性的基础上,研制了PVC ABS共混塑料,并对共混塑料的力学性能、热稳定性能进行了研究。结果表明,以合适配比制成的PVC ABS共混塑料具有优良的综合性能。     

Flame retardance of montmorillonite/rubber composites

The effect of dispersion of clay in rubber on the mechanical properties and flame retardance of rubber/montmorillonite (MMT) nanocomposites and rubber/MMT microcomposites were investigated in the present article, and the results were compared with the performance of silica reinforced rubber composites. Cone calorimeter test and limiting oxygen index test were employed to evaluate the flame retardance. From the results, it could be seen that the rubber/MMT nanocomposites always possessed the best flame retardance, such as lower peak heat release rate and higher fire performance index value. In addition, the rubber/MMT nanocomposites also showed better mechanical properties than the pure rubber and the other composites, especially in tear strength. With the rubber/silica composites, as expected, the silica could appropriately endow the rubber with flame retardance. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Investigation on polypropylene and polyamide-6 alloys/montmorillonite nanocomposites

Propropylene (PP) and polyamide-6 (PA6) alloys nanocomposites were prepared using melt intercalation technique by blending PP and PA6 while used organophilic montmorillonite (OMT). The melt intercalation of PP and PA6 alloys was carried out in the presence of a compatibilizer such as maleic anhydride-g-polypropylene (MAPP). Their structures were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and High Resolution Electronic Microscope (HREM). It was found different blend sequences have influence on the dispersibility of OMT and self-assembled structures of OMT appeared in PP and PA6 alloys. The crystallization behavior and crystal structure of PP and PA6 alloys/montmorillonite nanocomposites were investigated by X-ray diffraction. It showed that the blend sequences have influence on crystal structure and a higher cooling rate results in increasing of γ-crystalline phase. Flammability properties are characterized by Cone Calorimeter, which show an unusual phenomenon.     

Preparation,characterization, and properties of poly(vinyl chloride)/organophilic‐montmorillonite nanocomposites

Poly(vinyl chloride) (PVC)/organophilic‐montmorillonite (OMMT) nanocomposites were prepared by direct melt intercalation. PVC/compatibilizer ((vinyl acetate) copolymer (VAc))/OMMT nanocomposites were also prepared by melt intercalation by a masterbatch process. The effect of OMMT content on the nanostructures and properties of nanocomposites was studied. The nanostructures were studied by wide angle X‐ray diffraction (WAXD) and transmission electron microscopy (TEM). The linear viscoelastic properties and dynamic mechanical properties of PVC/OMMT nanocomposites were also investigated by an advanced rheometric expansion system (ARES) rheometer. The results showed that partially exfoliated and partially intercalated structures coexisted in the PVC/OMMT and PVC/VAc/OMMT nanocomposites. The mechanical properties test results indicated that the notched Charpy impact strengths of nanocomposites were improved compared to that of pristine PVC and had a maximum value at 1 phr OMMT loadings. The compatibilizer could further improve the impact strengths. But the existence of OMMT decreased the thermal stability of PVC/OMMT and PVC/VAc/OMMT nanocomposites. The linear viscoelastic properties test results indicated the dependence of G′ and G″ on ω shows nonterminal behaviors, and they had better processibility compared with pristine PVC. However, the glass transition temperatures of PVC/OMMT nanocomposites almost had little change compared to that of pristine PVC. POLYM. COMPOS., 27:55–64, 2006. © 2005 Society of Plastics Engineers     

羟基锡酸锌的制备及其对PVC电缆材料的阻燃消烟作用

研究了在Sn4+和Zn2+共存的水溶液中,以氢氧化钠为沉淀剂合成的纳米羟基锡酸锌（ZHS）。采用X射线粉末衍射、傅里叶红外和环境扫描电镜表征证明合成的ZHS是边长为380nm左右的纳米立方体。采用"熔融共混法"制备PVC电缆材料,通过极限氧指数、烟密度、环境扫描电镜炭渣形貌表征比较了ZHS与三氧化二锑（AO）对PVC的阻燃消烟作用。通过真空裂解气相色谱－质谱联用分析了阻燃PVC电缆材料的裂解产物,并结合燃烧性能的测试结果,推断了ZHS对PVC电缆材料阻燃消烟作用的机理。结果表明,用量相同时,ZHS对PVC电缆材料的成炭作用总是优于AO。添加量小于10份时,AO对LOI和SDR的影响优于ZHS;但添加量大于15份后,增加ZHS的用量可以进一步提高氧指数和降低烟密度值。     

Preparation and characterization of polystyrene–clay nanocomposites by free‐radical polymerization

The polymerizable cationic surfactant, vinylbenzyldimethylethanolammouium chloride (VBDEAC), was synthesized to functionalize montmorillonite (MMT) clay and used to prepare exfoliated polystyrene–clay nanocomposites. The organophilic MMT was prepared by Na⁺ exchanged montmorillonite and ammonium cations of the VBDEAC in an aqueous medium. Polystyrene–clay nanocomposites were prepared by free‐radical polymerization of the styrene containing intercalated organophilic MMT. Dispersion of the intercalated montmorillonite in the polystyrene matrix determined by X‐ray diffraction reveals that the basal spacing is higher than 17.6 nm. These nanocomposites were characterized by differential scanning calorimetry (DSC), transmission electron micrograph (TEM), thermal gravimetric analysis (TGA), and mechanical properties. The exfoliated nanocomposites have higher thermal stability and better mechanical properties than the pure polystyrene. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1370–1377, 2002