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用长链季铵盐和聚乙二醇(PEG)对蒙脱土进行交换反应,使季铵盐嵌入到蒙脱土的晶层间,使蒙脱土由亲水性变为亲油性;有机化改性后的蒙脱土与聚对苯二甲酸乙二醇酯(PET)熔融插层后可以较大地提高原树脂的耐热性和阻隔性能. 相似文献
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研究了用阳离子型改性剂十六烷基三甲基溴化铵和非离子型改性剂聚乙二醇(750)对蒙脱土进行两次插层改性的方法,用XRD和TGA等测试手段对有机改性后蒙脱土的内层结构进行了分析,实验表明其层间距和有机物含量有不同程度的增大,并通过分散实验证明了改性蒙脱土在有机溶剂中有很好的分散性。优化了制备复合改性蒙脱土的反应条件。 相似文献
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表面活性剂和硅烷偶联剂有机复合改性蒙脱土的制备及性能表征 总被引:1,自引:0,他引:1
为增加蒙脱土与有机物的相容性,采用十六烷基三甲基溴化铵(CTAB)与硅烷偶联剂(KH-560)对蒙脱土进行了有机复合改性。X-射线衍射和红外光谱的结果表明,CTAB已插入蒙脱土片层,平均层间距离从1.54 nm增大到3.98 nm和2.08 nm,而KH-560未插入蒙脱土片层,只是覆盖在蒙脱土表面,未改变蒙脱土的插层结构;分散性实验表明,表面活性剂和硅烷偶联剂有机复合改性的蒙脱土在苯乙烯、液体石蜡中的分散性好于其他改性蒙脱土;有机复合改性不仅增大了蒙脱土层间距,且改善了蒙脱土与聚氯乙烯的界面效果,提高了蒙脱土在聚氯乙烯基体中的分散均匀性,从而使聚氯乙烯/蒙脱土复合材料玻璃化转变温度的提高和力学性能的改善更明显。 相似文献
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聚丙烯/有机蒙脱土复合材料的制备、结构及性能 总被引:12,自引:1,他引:12
以改性聚丙烯作增容剂,用熔融插层法制备了聚丙烯/有机蒙脱土复合材料,研究了有机蒙脱土对复合材料力学性能的影响,并用X射线衍射研究了复合材料的结构。结果表明:增容剂增加了聚丙烯与蒙脱土片层之间的作用力,使蒙脱土片层间距增大,在聚丙烯基体中分散更好,因而使聚丙烯/有机蒙脱土复合材料的缺口冲击强度大幅度提高,当蒙脱土含量达5%时,缺口冲击强度提高120%,并且拉伸性能下降不大,约下降5%,其中有机蒙脱土TJ4的增韧效果最好。 相似文献
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天然钙蒙脱土的钠化改型和有机化改性 总被引:8,自引:0,他引:8
用碳酸钠作为钠化剂对天然钙蒙脱土进行了钠化改型,用CTAC、CTAB、C18三种插层剂分别对钠蒙脱土进行了有机插层改性。对钠化改型前后的蒙脱土进行了XRD、FTIR分析,对有机改性前后的蒙脱土用XRD、SEM、FTIR和TG-DTA等进行了表征和分析。结果表明:钙蒙脱土经钠化改型后,层间距增大,结晶度变差,活性增强;CTAC、CTAB、C18三种改性剂都能使蒙脱土的晶层间距有较大提高,其中,尤以C18改性剂的有机化效果最为显著;蒙脱土有机改性前后外观变化十分显著;有机改性蒙脱土的结构水无明显变化,层间吸附水显著减少,疏水的有机插层剂主要进入蒙脱土层间,大量脱去层间吸附的水分子,对晶体结构本身并无影响。有机改性后,蒙脱土的吸附水与层间水的脱水温度与脱水量均显著降低,有机插层剂的大量插入,改变了原土的亲水性使之变为疏水,并提高了其热稳定性。 相似文献
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采用有机复合改性的方法制备了改性蒙脱土,并采用原位聚合方法制备了尼龙-6/蒙脱土复合材料,利用FTIR、TG-DTA、XRD对有机蒙脱土进行了表征。结果表明,有机插层剂已进入蒙脱土的层间,使蒙脱土的层间距由原来的1.39 nm增大到2.32 nm,从而改善了它的分散性以及与尼龙-6之间的粘结作用,二者构成的纳米复合材料具有很好的力学性能。当加入2%的有机蒙脱土时,拉伸强度提高16%,冲击强度提高5%。 相似文献
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Novel Nonionic Polyurethane Surfactants and Ag Nanohybrids: Influence of Nonionic Polymeric Chains
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Nabel A. Negm Maher A. El Hashash Mona A. Youssif Eid A. Ismail Zizi I. Abdeen Nasser R. Abdel Rahman 《Journal of surfactants and detergents》2017,20(1):173-182
Five novel nonionic surfactants were prepared by the reaction of polyethylene glycol of different molecular weights with toluene diisocyanate. The obtained polyurethane polymers were reacted with oleic acid to obtain the nonionic polyurethane surfactants. The structures of the synthesized compounds were determined by using: Fourier Transform Infrared Spectroscopy (FTIR) and their average molecular weights by means of GC analysis. Silver nanohybrids of the nonionic polyurethane surfactants were prepared via physical combination by chemically prepared silver nanoparticles. The silver nanohybrids were determined using: UV, TEM, and DLS spectroscopy. The influence of the nonionic chain length (polyethylene glycol chains) on the surface activity of the synthesized nonionic polyurethane oleate surface active agents and their silver nanohybrids was studied. The results of surface activity of the nonionic polyurethanes oleate and their nanohybrids showed an increase in the critical micelle concentration by decreasing the polyethylene glycol chain lengths. The nanohybrids were also more surface active. Longer polyethylene glycol chains provide good protection for the formed silver nanoparticles than the shorter chains. 相似文献
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采用熔融插层法成功制备了聚丙烯(PP)/尼龙6(PA6)/有机化蒙脱石(OMMT)纳米复合材料.用X射线衍射分析(XRD)和透射电镜(TEM)观察了OMMT层间距的变化和材料的结构;用示差扫描量热法(DSC)和热重分析(TG)研究了热性能,并考察了纳米复合材料的拉伸强度.研究结果表明,OMMT的层间距由2.200 nm扩大到2.800 nm,PP/PA6合金高分子链取代了有机化蒙脱石层间的十六烷基三甲基溴化铵而进入到蒙脱石的片层间,加入质量分数为4%的OMMT的复合材料不仅使材料的拉伸强度提高了约15%,还提高了材料的热稳定性,使剩炭率增加了8.1%. 相似文献
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利用多孔二氧化硅的良好吸附性,将不同计量的聚乙二醇在硅溶胶胶凝过程中吸附于硅凝胶的孔隙结构中制备聚乙二醇/二氧化硅定形相变材料(PEG/SiO2 SSPCM);并将其与熔融沥青共混获得不同聚乙二醇含量的沥青-定形相变材料(Asphalt-SSPCM)。借助孔径分析仪和扫描电镜(SEM)表征了载体二氧化硅孔结构和PEG/SiO2 SSPCM的表观形貌;通过X射线衍射仪(XRD)、综合热分析仪(DSC/TG)和傅里叶红外光谱仪(FTIR)考察了沥青中PEG/SiO2 SSPCM的晶体结构、储热性能、热稳定性及化学兼容性;通过本文作者课题组研发的温度模拟试验箱测试了Asphalt-SSPCM的降温效果。结果表明,二氧化硅凝胶具有丰富的孔结构并能将聚乙二醇吸附于其介孔结构中;沥青中PEG/SiO2 SSPCM仍含有聚乙二醇晶体,其储热能力随聚乙二醇含量的增加而增大,当聚乙二醇含量为76.1%时,相变焓高达117.5J/g,且不同聚乙二醇含量的沥青-定形相变材料均表现出良好的热稳定性;PEG/SiO2 SSPCM与沥青的化学兼容性良好,二者之间仅是物理作用;Asphalt-SSPCM的降温效果显著,可有效改善沥青路面的高温性能;并基于相变理论,分析了沥青-定形相变材料的相变储热原理。 相似文献
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采用大豆分离蛋白和玻纤作原料,并用聚乙二醇(300)进行增塑,采用传统的热压成型方法来制备大豆分离蛋白/玻纤复合材料。加入10份聚乙二醇(300),SPI/GF复合材料拉伸强度和吸水率降低,断裂伸长率和流动性则呈明显升高。 相似文献
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Asymmetric membranes of polyvinyl chloride modified with polyethylene glycol as pore former have been prepared by nonsolvent-induced phase separation method using N,N-dimethylacetamide/water as solvent/nonsolvent system. The phase diagram of polyvinyl chloride/polyethylene glycol/N,N-dimethylacetamide/water system showed that polyethylene glycol favors the demixing process. The prepared membrane is characterized by scanning electron microscopy, ATR-FTIR, equilibrium water content, porosity, pure water flux, and contact angle. The addition of polyethylene glycol favored the formation of finger-like structure of polyvinyl chloride membrane initially, and at higher polyethylene glycol concentration, a spongy structure is obtained. The prepared membrane possesses high water flux, excellent thermal stability, and sufficient mechanical strength suitable for ultrafiltration operation. 相似文献
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The polyethylene glycol/cement composites as thermal energy storage materials were prepared by blending polyethylene glycol and cement. In composite materials, polyethylene glycol (PEG) is used as the phase change material for thermal energy storage and cement acts as the supporting material. A Fourier transformation infrared spectroscope (FT‐IR), x‐ray diffractometer (XRD), and scanning electronic microscope (SEM) were used to determine the chemical structure, the crystalloid phase, and microstructure of the polyethylene glycol/cement composites, respectively. The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetry analyzer (TGA). The SEM results showed that the polyethylene glycol was well dispersed in the porous network of the cement. 相似文献