环氧树脂/有机化蒙脱土纳米复合材料的研究

采用插层原位聚合法制备了环氧树脂/有机化蒙脱土(EP/OMMT)纳米复合材料,探讨了OMMT的剥离结构及其对EP/OMMT纳米复合材料热性能和力学性能等影响。结果表明:当w(OMMT)=7%时,EP/OMMT纳米复合材料的热变形温度提高了24～27℃,Tg(玻璃化转变温度)提高了20～30℃,并且其力学性能和耐湿热性能均优于纯EP体系。     

聚酰亚胺/有机蒙脱土/丁苯橡胶复合材料性能的研究

将聚酰亚胺(PI)与有机蒙脱土(OMMT)混合,制备了PI/OMMT粉状材料;将粉状材料与丁苯胶乳(SBR)混合,制备了颗粒状PI/OMMT/SBR复合材料.SEM照片显示,有机蒙脱土可改善聚酰亚胺与丁苯橡胶的相容性.X射线衍射(XRD)结果表明,聚酰亚胺分子链与丁苯橡胶分子链一起插入有机蒙脱土层间,使层间距变大;有机蒙脱土作为交联点存在.动态力学性能测试结果表明,在频率扫描下,加入PI/OMMT后丁苯橡胶的G′最高,但tanδ较低.     

乳液插层法制备丁苯橡胶/有机蒙脱土纳米复合材料

对蒙脱土(MMT)进行了有机化改性,采用乳液插层法制备了丁苯橡胶(SBR)/有机蒙脱土(OMMT)纳米复合材料,用透射电子显微镜、X射线衍射法对OMMT及复合材料进行了表征,研究了复合材料的物理机械性能及动态力学性能.结果表明,MMT的层间距为1.47 nm,OMMT的层间距增大到2.94 nm;OMMT片层均匀分散在SBR基体中,具有良好的界面相容性;随着OMMT用量的增加,SBR/OMMT纳米复合材料的物理机械性能明显改善,且具有低填充量高增强效果的特点;SBR/OMMT纳米复合材料具有与SBR/炭黑N 330复合材料相当的抗湿滑性能,同时具有更小的滚动阻力.     

用原位有机改性法制备的溴化丁基橡胶／蒙脱土复合材料的性能

采用原位有机改性法制备了溴化丁基橡胶(BIIR)/蒙脱土(MMT)复合材料,并对其硫化特性和力学性能进行了研究,用X射线衍射仪时复合材料中MMT的层间距进行了表征,并与钠基蒙脱土(Na-MMT)、有机蒙脱土(OMMT)和BIIR形成的复合材料进行了对比.结果表明,用原位有机改性法制备的BIIR/MMT复合材料的硫化特性和力学性能优于BIIR/Na/MMT复合材料,甚至优于BIIR/OMMT复合材料;采用原位有机改性法,可使BIIR/MMT体系中MMT的插层效果明显改善.     

有机MMT对高密度聚乙烯改性的研究

采用十二烷基三甲基氯化铵、十六烷基三甲基氯化铵、十六烷基三甲基溴化铵和双十八烷基二甲基氯化铵4种阳离子表面活性剂对钠基蒙脱土(MMT)进行有机化处理,制备了有机MMT(OMMT)。将OMMT与高密度聚乙烯(HDPE)进行熔融插层制备了HDPE／OMMT纳米复合材料,研究了OMMT的层间距同季铵盐烷基链的关系。结果表明,OMMT的层间距随烷基链长度的增加而增大;随着OMMT含量的增加,HDPE／OMMT纳米复合材料的断裂伸长率和拉伸强度降低,弯曲弹性模量增加,弯曲强度出现极大值,使该纳米复合材料的力学性能得到了一定的改善。     

原位聚合法制备有机蒙脱土/聚碳酸酯二醇型热塑性聚氨酯弹性体复合材料

用十六烷基三甲基溴化铵改性钠基蒙脱土(MMT),以聚碳酸酯二醇(PCDL)为软段,4,4'-二苯基甲烷二异氰酸酯/1,4-丁二醇为硬段,采用两步原位聚合法制备了插层型有机蒙脱土(OMMT)/PCDL型热塑性聚氨酯弹性体(PCU)复合材料,通过傅里叶变换红外光谱和X射线衍射法表征了OMMT和复合材料,并考察了OMMT含量对复合材料耐热性能、结晶性能及物理机械性能的影响。结果表明,OMMT层间距由MMT的1.217 nm扩大到1.856 nm,复合材料的层间距扩大至3.425 nm;复合材料的耐热性能、结晶性能和物理机械性能均优于纯PCU,当OMMT质量分数为1%时,复合材料的耐热性能最佳;当OMMT质量分数为3%时,复合材料的结晶性能和物理机械性能最佳。     

EP/有机化蒙脱土纳米复合材料的制备与性能研究

采用插层聚合法制备了环氧树脂/有机化蒙脱土(EP/OMMT)纳米复合材料。利用红外光谱(FT-IR)法和X射线衍射(XRD)法对OMMT结构进行了分析,并探讨了OMMT含量对不同纳米复合材料的结构、热性能和力学性能等影响。结果表明:经EP插层后,OMMT的层间距变大,并且发生了比较完全的剥离行为;OMMT的引入可有效提高不同纳米复合材料的热变形温度和玻璃化转变温度(前者提高了14～29℃,后者提高了2～27℃),并且其力学性能和耐湿热性能均优于纯EP体系。     

母料法制备尼龙6/蒙脱土纳米复合材料及其性能

以高流动性聚丙烯接枝马来酸酐(PP-g-MAH)为载体树脂,制备了接枝聚丙烯/有机蒙脱土插层母料,并以此为增强剂制备了PA6/接枝聚丙烯/有机蒙脱土纳米复合材料,研究了有机蒙脱土(OMMT)含量对复合体系力学性能和耐热性能的影响。通过X射线衍射(XRD)、透射电子显微镜(TEM)研究了复合材料的微观结构。结果表明:在所制备的插层母料中,PP-g-MAH大分子能够部分插入OMMT的晶片层间,其层间距有所增大。母料法制备的PA6/接枝聚丙烯/有机蒙脱土纳米复合材料的力学性能得到了较大提高,当OMMT含量为6%时,拉伸强度和弯曲强度分别比PA6/PP-g-MAH共混体系提高了24%和25.1%。     

SEBS/PP/OMMT纳米复合材料的制备及性能

通过对蒙脱土的有机化处理,利用熔融插层的方法制备了苯乙烯-乙烯/丁烯-苯乙烯三嵌段聚合物(SEBS)/聚丙烯(PP)/有机蒙脱土(OMMT)纳米复合材料,对其结构、热性能及力学性能进行了研究.结果表明,少量有机化蒙脱土能够大幅度提高SEBS中聚苯乙烯嵌段的玻璃化转变温度,而对材料的力学性能影响很小.     

HIPS／OMMT纳米复合材料的性能研究

采用熔融插层法制备出了高抗冲聚苯乙烯(HIPS)/有机改性蒙脱土(OMMT)纳米复合材料,研究了OMMT用量对复合材料力学性能、阻燃性能和热稳定性的影响,并分析了OMMT在高抗冲聚苯乙烯基体中的分散状态.结果表明,OMMT的加入有助于提高高抗冲聚苯乙烯基体的力学性能、阻燃性能和热稳定性.熔融插层法可以使高抗冲聚苯乙烯的大分子链有效地插人到OMMT的片层之间.     

Effect of OMMT on microstructure,crystallisation and rheological behaviour of UHMWPE/PP nanocomposites under elongation flow

Different loadings of organo-montmorillonite (OMMT) were mixed with ultra-high molecular weight polyethylene (UHMWPE)/polypropylene (70/30) composites under elongation flow. Results showed that ideal dispersion of OMMT nanoparticles could be achieved and most OMMTs intercalated and exfoliated effectively. However, the layer spacing of OMMT decreased with the increase in the content of OMMT. UHMWPE was surrounded by the OMMT layers, and its shape evolved from a compatible phase to a sphere. OMMT caused heterogeneous nucleation in the blends, leading to a high crystallisation temperature. Meanwhile, the intercalated and exfoliated OMMTs promoted the motion of polymer chains, and inhibited the crystallisation process of UHMWPE in the composites. The crystallinity of UHMWPE with 5% OMMT markedly decreased from 48.39% to 41.46%. Various rheological analyses confirmed that the complex viscosity of composites and the storage modulus decreased first and then increased with the increase in the content of OMMT. UHMWPE/PP with 5% OMMT exhibited the ideal mobility.     

Preparation and characterization of thermoplastic polyurethane/organoclay nanocomposites by melt intercalation technique: Effect of nanoclay on morphology,mechanical, thermal,and rheological properties

Nanocomposites based on thermoplastic polyurethane (TPU) and organically modified montmorillonite (OMMT) were prepared by melt blending. Organically modified nanoclay was added to the TPU matrix in order to study the influence of the organoclay on nanophase morphology and materials properties. The interaction between TPU matrix and nanofiller was studied by infrared spectroscopy. Morphological characterization of the nanocomposites was carried out using X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy techniques. The results showed that melt mixing is an effective process for dispersing OMMT throughout the TPU matrix. Nanocomposites exhibit higher mechanical and thermal properties than pristine TPU. All these properties showed an increasing trend with the increase in OMMT content. Thermogravimetric analysis revealed that incorporation of organoclay enhances the thermal stability of nanocomposites significantly. Differential scanning calorimetry was used to measure the melting point and the glass transition temperature (T_g) of soft segments, which was found to shift toward higher temperature with the inclusion of organoclays. From dynamic mechanical thermal analysis, it is seen that addition of OMMT strongly influenced the storage and loss modulus of the TPU matrix. Dynamic viscoelastic properties of the nanocomposites were explored using rubber process analyzer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

The modification of lanthanum‐exchanged montmorillonite with anionic surfactants to enhance the thermal stability of polyvinyl chloride

A series of thermally stable lanthanum organic montmorillonites (La‐OMMTs) were successfully prepared by modifying Na‐MMT with anionic surfactants and lanthanum chloride. Fourier transform infrared spectroscopy and X‐ray diffraction indicated that the anionic surfactants resided in the interlayer spaces and expanded the MMT basal spacing from 1.23 nm to 3.3 nm. Thermogravimetric and differential thermal analysis (TG/DTA) results showed that the intercalation of sodium dodecyl sulfonate into the lanthanum organic MMT resulted in its excellent thermal stability. The use of the La‐OMMT samples in polyvinyl chloride (PVC) resins was tested, and the TG/DTG results revealed that the three La‐OMMTs could significantly enhance the thermal stability of PVC. The modified La‐OMMT with the highest thermal stability is expected to be useful in polymer/layered silicate nanocomposites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41535.     

TPU与CPE、HPVC共混物的研究

以CPE和CPE／HPVC为改性剂,用熔融共混的方式对TPU的共混体系进行了系统的研究。对TPU／CPE和TPU／CPE／HPVC共混体系的力学、耐寒及流变性能进行了测试及分析。实验结果表明：CPE及CPE／HPVC的加入,虽使体系的力学性能有所降低,但能明显改善TPU的加工性能,并且基本保持了TPU优异的耐寒性。     

Synthesis of organic montmorillonite contained polyhedral oligomeric silsesquioxane and its nanocomposites with poly(l‐lactide)

Three kinds of novel organic montmorillonites (OMMTs) were prepared by reacting the amino polyhedral oligomeric silsesquioxanes (POSSs) with the OMMTs that had already been modified by cationic surfactants. The layer spacing of OMMT increased from 1.68 to 3.81 nm after being intercalated by POSS. Poly(l ‐lactide) (PLLA) based nanocomposites with montmorillonites were produced by melt compounding. The PLLA nanocomposites with POSS modified OMMT were comprised of a random dispersion of intercalated/exfoliated aggregates of layered silicates throughout the PLLA matrix. The incorporation of POSS modified OMMT resulted in a significant increase in both crystallization temperature and decomposition temperature for 5% weight loss in comparison with the virgin PLLA. Gas Permeation Analysis showed that the increase of the montmorillonite concentration in the polymer matrix led to an expected decrease in permeation values. Gas barrier properties of the nanocomposites were compared with those predicted by phenomenological models such as the Nielsen model and Cussler model. POLYM. ENG. SCI., 54:2489–2496, 2014. © 2013 Society of Plastics Engineers     

Effects of thermoplastic polyurethane on the properties of poly(lactic acid)/organo‐montmorillonite nanocomposites based on novel vane extruder

Polylactic acid (PLA)/organo‐montmorillonite (OMMT) nanocomposites toughened with thermoplastic polyurethane (TPU) were prepared by melt‐compounding on a novel vane extruder (VE), which generates global dynamic elongational flow. In this work, the mechanical properties of the PLA/TPU/OMMT nanocomposites were evaluated by tensile, flexural, and tensile tests. The wide‐angle X‐ray diffraction and transmission electron microscopy results show that PLA/TPU/OMMT nanocomposites had clear intercalation and/or exfoliation structures. Moreover, the particles morphology of nanocomposites with the addition of TPU was investigated using high‐resolution scanning electronic microscopy. The results indicate that the spherical TPU particles dispersed in the PLA matrix, and the uniformity decreased with increasing TPU content (≤30%). Interestingly, there existed abundant filaments among amount of TPU droplets in composites with 30 and 40 wt% TPU. Furthermore, the thermal properties of the nanocomposites were examined with differential scanning calorimeter and dynamic mechanical analysis. The elongation at break and impact strength of the PLA/OMMT nanocomposites were increased significantly after addition of TPU. Specially, Elongation at break increased by 30 times, and notched impact strength improved 15 times when TPU loading was 40 wt%, compared with the neat PLA. Overall, the modified PLA nanocomposites can have greater application as a biodegradable material with enhanced mechanical properties. POLYM. ENG. SCI., 54:2292–2300, 2014. © 2013 Society of Plastics Engineers     

Effect of Organo-Modified Montmorillonite on the Morphology and Properties of SEBS/TPU Nanocomposites

In this study, novel polystyrene-b-poly(ethylene-butylene)-b-polystyrene (SEBS)/thermoplastic polyurethane (TPU)/organo-modified montmorillonites (OMMT) nanocomposites were prepared by melt mixing. Three different organo-modified montmorillonites, DK2, DK3, and DK4 (listed in descending order of hydrophilicity) were selected. The compatibilizing and reinforcing effects of OMMT on the structure, morphology, thermal stability, mechanical and rheological properties of the SEBS/TPU blends were studied. It was found that the hydrophilic DK2 nanoparticles were largely located in the continuous TPU phase and partially dispersed at the phase interphase, whereas DK3 and DK4 nanoparticles were preferentially located at the phase interface with an intercalated/exfoliated and intercalated structure, respectively. Scanning electron microscopy (SEM) results showed that SEBS/TPU/OMMT nanocomposites exhibited a more densely organized and interconnected structure compared with SEBS/TPU blends. Better thermal property was achieved after adding DK3, with the tensile properties of the SEBS/TPU increased considerably. Rheological analysis revealed that hydrophilic DK2 nanoparticles were more effective in improving rheology properties and showed a more pronounced nonlinear effect. The prepared SEBS/TPU/OMMT nanocomposites displayed desired thermal, mechanical and rheological properties, which are important for many applications. POLYM. ENG. SCI., 60:850–859, 2020. © 2020 Society of Plastics Engineers     

Thermal characteristics of organoclay and their effects upon the formation of polypropylene/organoclay nanocomposites

Summary We have examined thermal characteristics of two types of organically modified montmorillonite (OMMT) with different alkylammonium cations and their effects upon the formation of PP nanocomposite, when using a maleic anhydride grafted polypropylene oligomer (maPP) as a compatibilizer. The microstructure of the composite has been characterized by X-ray diffraction (XRD) analysis, transmission electron microscopy and Fourier transform infrared spectroscopy. OMMT showed the decrease of the interlayer spacing at the processing temperature, due to the release of organic ion by thermal decomposition. Thermal characteristics of OMMTs depended greatly on the interlayer structure of OMMT. When the OMMT with small interlayer spacing and less organophilicity was used, PP composite resulted in the only partial exfoliation due to thermal decomposition of the clay layers. Received: 21 June 2000/Revised version: 11 August 2000/Accepted: 11 August 2000     

Structural and ordering behavior of lamellar polystyrene‐block‐polybutadiene‐block‐polystyrene triblock copolymer containing layered silicates

Nanocomposites based on organically modified montmorillonites (OMMTs) and sodium montmorillonite (CLO‐Na⁺) with poly(styrene‐b‐butadiene‐b‐styrene) (SBS) diblock copolymer have been investigated. Solution blending of OMMT suspension in toluene with SBS and subsequent static casting and annealing resulted in transparent films. Final samples were processed by compression molding. The intercalation spacing in the nanocomposites, microphase separation of the SBS, and the degree of dispersion of nanocomposites were investigated by X‐ray diffraction (Wide and small‐angle X‐ray scattering), transmission optical microscopy (TOM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The increase of basal spacing of OMMT in the nanocomposites suggested the intercalation of SBS. The lamellar structure perfection was extensively affected by both OMMT. AFM images and TOM micrographs only showed well dispersed but not exfoliated nanocomposites. On the other hand, TEM showed inserted tactoids into both blocks depending on the surfactant used (stained samples) and the dispersion of those tactoids (unstained samples). Fourier transform infrared spectroscopy indicated only the presence of the OMMT into the SBS. Deviations of the decomposition pathway of pristine SBS with addition of the OMMT were found by thermogravimetric analysis. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Stretchable strain sensors based on polyaniline/thermoplastic polyurethane blends

Polymer Bulletin - Thermoplastic polyurethane/polyaniline-based stretchable strain sensors were prepared via in situ polymerization of aniline in the TPU solution in the form of thin films. The...