聚有机硅氧烷/蒙脱土纳米复合乳液的制备及稳定性研究

以十二烷基苯磺酸(DBSA)为插层剂改性蒙脱土(MMT),制得了有机蒙脱土(OMMT),采用原位插层聚合法,以八甲基环四硅氧烷(D4)、乙烯基二三甲氧基硅烷(A-171)和OMMT为原料制备了聚有机硅氧烷/蒙脱土(PDMS/OMMT)纳米复合乳液,研究了DBSA添加工艺、OMMT用量、反应温度、A-171及乳化剂用量等对D4转化率和乳液稳定性的影响,并采用XRD、FT-IR等手段对OMMT及PDMS/OMMT低聚体的结构进行了表征.结果表明:在反应初始阶段通过外加DBSA,可使D4在OMMT层间开环聚合,形成剥离结构;当m(OMMT):m(D4)为20,反应温度为80℃、m(A-171):m(D4)和m(乳化剂):m(D4)分别为2.0和3.0时,D4转化率达到71.3%,PDMS/OMMT乳液的稳定性最好.     

聚消旋乳酸/蒙脱土纳米复合材料热稳定性的研究

通过熔融混合制得了聚消旋乳酸(PDLLA)／蒙脱土(MMT)纳米复合材料。研究了蒙脱土的加入量对其结构和热稳定性能的影响,结果表明,聚消旋乳酸的分子链已经插入到蒙脱土片层的层间隙中形成了嵌入式的插层结构。蒙脱土的加入使PDLLA／MMT纳米复合材料的玻璃化转变温度增加,其热稳定性明显改善。与纯PDLLA相比,它的起始热分解温度至少提高了22．5℃。蒙脱土的最佳加入量为5％,其断裂伸长率可提高近一倍。     

苯乙烯-丙烯酸丁酯／蒙脱土纳米复合涂料的研究

采用乳液插层聚合法合成苯乙烯-丙烯酸丁酯/蒙脱土(MMT)纳米复合阻燃涂料,对涂膜的机械性能和阻燃性进行了研究,结果表明:纳米插层复合阻燃涂料不但能增加涂膜的机械性能,而且还能提高涂膜的阻燃性.     

乳液法聚甲基丙烯酸甲酯／蒙脱土纳米复合材料的合成与表征

利用Na2SiO3的改性机理来纯化Na基蒙脱土,通过调节体系的pH值及其聚合阴离子的作用,使蒙脱土边面带负电荷,有效调节蒙脱土在水中的分散状态,使其与有机阳离子的交换反应充分进行,得到有机蒙脱土的阳离子交换量达115mmol/110g,并且能均匀分散在甲基丙烯酸甲酯9MMA）单体中,借助普通的乳液聚合方法,制备出PMMA／有机蒙脱土纳米复合材料,复合材料经甲苯抽提,FTIR,XRD,TEM,DSC,TGA等一系列分析方法表征,表明有机蒙脱土在PMMA基体中已达到纳米级分散,多数已发生剥离,而且复合材料的热性能较纯PMMA有很大提高,其Tg和Td最大分别提高31．45℃和42．13℃。     

环氧树脂/蒙脱土纳米复合涂料防腐性能的研究进展

环氧树脂涂料在防腐领域中应用广泛,但仍需进行改性以满足应用需求,一个比较经济、有效的途径就是添加纳米填料。蒙脱土片层分散在环氧树脂基料中时,能有效阻隔腐蚀性介质穿过涂膜,进而提高纳米复合涂料的防腐性能。简单介绍了蒙脱土的结构,环氧树脂/蒙脱土纳米复合涂料的制备方法。综述了近年来环氧树脂/蒙脱土纳米复合涂料防腐性能的研究进展。     

聚双环戊二烯/蒙脱土纳米复合材料的性能

采用反应注射成型工艺制备了聚双环戊二烯／有机蒙脱土纳米复合材料,用X射线衍射仪、透射电子显微镜等研究了纳米复合材料的结构,测试了复合材料的力学性能。结果表明,制备的材料为剥离型纳米复合材料,有优越的拉伸强度和弯曲强度,并且具有良好的韧性。     

乳液法有机蒙脱土/SBR纳米复合技术的改进

对现有大分子乳液插层法制备蒙脱土 /SBR纳米复合材料技术进行改进。试验结果表明 ,使用低分子醇类混合物预分散有机蒙脱土 ,可使疏水的有机蒙脱土直接用于乳液插层法制备有机蒙脱土 /SBR纳米复合材料 ;在SBR胶乳中加入少量带羟基的聚合物水溶液 ,能够使有机蒙脱土层间距扩大 ,有利于提高插层动力 ;超声波对聚合物插层没有明显的强化作用     

聚丙烯酰胺/蒙脱土复合材料热学性质的研究

高吸水性聚丙烯酰胺／蒙脱土复合材料热稳定性实验证明其具有较好的热稳定性。使用自制装置对其热学性质进行研究的结果显示了,该材料可以提高流体的保温性能,延长保温时间,具有较好的应用前景。     

聚对苯二甲酸丁二醇酯/蒙脱土纳米复合材料的研究进展

本文综述了聚对苯二甲酸丁二醇酯(PBT)/蒙脱土(MMT)纳米复合材料的两种制备方法、性能及其表征方法。用MMT改性PBT可以提高PBT的结晶速率,能改善PBT的热学性能和力学性能,是目前PBT改性的新方向。     

蒙脱土改性纳米复合乳液的研究进展

纳米技术是一项前沿科学技术,目前,聚合物,蒙脱土纳米复合材料是重要的工程材料之一。由于蒙脱土具有层状硅酸盐的特殊结构,使得聚合物,蒙脱土纳米复合材料的各项性能均得到较大改善。介绍了蒙脱土的特性及其复合材料的结构,详细介绍了近年来国内外学者采用共混法和插层聚合法制备蒙脱土改性纳米复合乳液所做的研究工作。对蒙脱土改性不同乳液的应用研究现状进行了综述。指出了乳液法制备聚合物／蒙脱土纳米复合材料研究中存在的问题和应努力的方向。     

Swelling behavior and structural characteristics of polyvinyl alcohol/montmorillonite nanocomposite hydrogels

A series of nanocomposite hydrogels based on polyvinyl alcohol containing 0–10 wt % of the organically modified montmorillonite clay were prepared by freezing‐thawing cyclic method. The morphology of the nanocomposite hydrogels was observed by the scanning electron microscopy technique. The structural properties were determined by measuring the network mesh size, crosslinking density, and average molecular weight of polymer chains between crosslinks. The swelling behavior and the effect of swelling medium temperature on the swelling kinetics and characteristics of the nanocomposite hydrogels were also investigated. The results showed that two structural characteristics i.e., network mesh size and average molecular weight of polymer chains between crosslinks have inverse dependence on the clay loading level in the nanocomposite hydrogel, while crosslinking density shows completely direct dependence. Swelling measurements demonstrated a linear relation between the degree of swelling and the square root of immersion time at all swelling medium temperatures. The results indicated that the swelling characteristics of the nanocomposite hydrogels including the equilibrium degree of weight and volume swelling and the equilibrium water content were decreased by increasing the quantity of the clay incorporated into the hydrogel as well as by decreasing the temperature of swelling medium. While, the time required to reach to the equilibrium condition, as another swelling characteristic of the hydrogels, exhibited a completely opposite behavior. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

改性聚乙酸乙烯酯乳液的研究

研制了一种改性聚乙酸乙烯酯乳液 ,通过乳化稳定剂聚乙烯醇的缩醛化 ,用丙烯酸进行核壳乳液共聚和添加松香树脂共混相结合的方法 ,成功地解决了通用乙酸乙烯酯乳液的抗水性、抗冻性和抗蠕变性较差的问题     

Synthesis and characterization of polyvinyl acetate/montmorillonite nanocomposite by in situ emulsion polymerization technique

Exfoliated polyvinyl acetate/montmorillonite nanocomposite (PVAc/MMT) was prepared via in situ emulsion polymerization. The resulting PVAc with various organophilic MMT contents was investigated. In the nanocomposite latex preparation, sodium lauryl sulfate (SLS), ammonium persulfate (APS), and poly (vinyl alcohol) (PVA) are used as anionic emulsifier, conventional anionic initiator, and stabilizer, respectively. The samples were characterized using elemental analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM). The XRD and AFM results demonstrate that the MMT well dispersed at molecular level in the PVAc matrix. Thermal properties of the nanocomposite were studied by using differential scanning calorimetric analysis (DSC). The exfoliated PVAc/MMT nanocomposite showed a higher glass transition temperature and a better thermal stability compared to the pure PVAc.     

聚醋酸乙烯乳液的研究进展

综述了国内外在改进聚醋酸乙烯酯 (PVAc)乳液的耐水性、稳定性、粘合性及其它性能方面的研究进展 ,并对PVAc乳液的发展前景进行了展望。     

不同性质的聚乙烯醇对聚醋酸乙烯乳液性能的影响

采用半连续乳液聚合的方法合成聚醋酸乙烯乳液。通过对乳液的粒子形态、压缩剪切强度、粘度、冻融稳定性的分析,讨论了不同性质的聚乙烯醇作为保护胶体,对聚醋酸乙烯乳液胶粘剂性能的影响。     

Novel high-strength montmorillonite/polyvinyl alcohol composite film enhanced by chitin nanowhiskers

Nanomaterials can be used as reinforcement phase to improve the performance of polymers. A simple method to prepare a composite film with super high tensile strength was used in this study. The properties of montmorillonite (MMT)/polyvinyl alcohol (PVA) films reinforced by chitin nanowhisker (CNW) have been evaluated. The structures and properties of films were analyzed by atomic force microscope (AFM), Fourier transforms infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and tensile testing. The results of FTIR and XRD showed that no chemical interaction occurred among MMT, PVA, and CNW. The SEM and AFM images suggested that the obtained composite films with the three substances had a relatively uniform layered structure and relatively smooth. The temperature at the onset of decomposition of the composite films was increased from 262.0 to 282.3°C by the addition of CNW. The tensile strength of the MMT/PVA/CNW film was reached 263.5 MPa, which was increased approximately 382% compared with the MMT/PVA film. According to these results, the composite film could be potentially used in packaging materials.     

聚醋酸乙烯酯乳液改性研究进展

综述了国内外对聚醋酸乙烯酯乳液的改性研究,如耐水性、稳定性等方面的研究进展,并对聚醋酸乙烯酯乳液的发展前景进行展望。     

聚乙酸乙烯酯乳液改性研究进展

介绍了聚乙酸乙烯酯乳液改性的研究进展及各种改性方法和技术,包括共聚、共混、保护胶体的化学改性,引发剂、乳化剂、交联剂和添加剂的改变以及辐射法制备聚乙酸乙烯酯乳液等。以某种改性方法为主,辅以其他改性方法,或者多种方法共同改性已经成为聚乙酸乙烯酯乳液改性的发展趋势。     

聚醋酸乙烯乳液组成与性质

]本文从实用角度概述了聚醋酸乙烯乳液的组成（乳化剂、保护肢体、引发剂、增塑剂、改质剂等）及影响乳液性质的各种因素（例如：聚乙烯酸、单体、引发剂的种类与添加方法等）。     

一种改性聚乙酸乙烯酯乳液的合成与性能

通过在乳液聚合过程中引入单体N-羟甲基丙烯酰胺参与共聚的方法,制得一种改性聚乙酸乙烯酯乳液,实验结果表明,该乳液具有良好的稳定性、耐水性、成膜性、粘接性,N-羟甲基丙烯酰胺的用量以乙酸乙烯酯质量的1%~2%为宜,聚合周期比普通PVAc乳液缩短40%左右。