碳酸钙/聚甲基丙烯酸甲酯纳米复合粒子制备及表征

研究了纳米碳酸钙存在下的甲基丙烯酸甲酯的无皂乳液聚合。对所得的产品用热甲苯进行抽提,并用TEM、IR、XPS等手段进行分析。结果表明,聚合后纳米碳酸钙粒子表面被PMMA所包覆,并且PMMA不能完全被热甲苯抽提出来,这是由于这部分PMMA是通过化学键接枝在纳米碳酸钙的表面的缘故。     

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／100g土，并且能均匀分散在甲基丙烯酸甲酯(MMA)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℃。     

纳米TiO2/甲基丙烯酸甲酯原位乳液聚合研究

采用原位乳液聚合方法制备聚甲基丙烯酸甲酯(PMMA)包覆TiO2(TiO2／PMMA)，发现纳米TiO2对甲基丙烯酸甲酯的聚合无阻聚作用。研究表明：PMMA包覆在纳米TiO2表面主要为物理包覆，有少量化学包覆。在丙烯酸涂料中，TiO2／PMMA比TiO2更易分散。用TiO2／PMMA制得的涂料流平性好，涂膜性能优良。     

PbSe/聚甲基丙烯酸甲酯纳米复合材料的制备及表征

采用超声电化学法制备出水相硒化铅(PbSe)纳米晶体,并将其掺杂到聚甲基丙烯酸甲酯(polymethyl methacrylate,PMMA)材料中,通过本体聚合法制备出PbSe/PMMA纳米复合材科.用X射线衍射、透射电镜、扫描电镜对PbSe纳米晶体和PbSe/PMMA纳米复合材料的形貌进行了表征.结果表明:超声电化...     

纳米 Sb2O3/MMA原位乳液聚合研究

研究了纳米Sb2O3/MMA体系的原位乳液聚合反应，结果表明，纳米Sb2O3对MMA的聚合无阻聚作用，表面包覆的聚甲基丙烯酸甲酯能有效地解决纳米粒子的团聚问题。     

聚甲基丙烯酸甲酯/层状无机物纳米复合材料的研究进展

综述了目前聚甲基丙烯酸甲酯/层状无机物纳米复合材料的研究现状,并对其今后的发展方向进行了展望。     

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℃。     

纳米粒子种类对PMMA／纳米复合材料性能的影响

研究了胶体SiO2、粉体SiO2、有机改性蒙脱土OMMT等不同纳米粒子种类对纳米复合材料性能的影响,通过红外光谱、X射线衍射、热重分析和动态力学性能等测试手段对复合材料进行了分析表征。结果表明,OMMT和胶体SiO2与聚甲基丙烯酸甲酯（PMMA）的复合效果最好;OMMT的加入对复合材料的热性能有一定提高,而胶体和粉体SiO2的加入提高了复合材料的储能模量。     

纳米铁粒子表面接枝聚合甲基丙烯酸甲酯

采用直流电弧等离子体法制备纳米铁粉,利用甲基丙烯酸(MAA)和盐酸处理纳米铁粉,通过乳液聚合方法,在纳米铁粉存在下MMA原位聚合,形成纳米铁/聚甲基丙烯酸甲酯复合粒子。分析结果表明,MMA在纳米铁粒子表面接枝聚合,纳米铁粉表面的双键参与了聚合反应,所形成的复合粒子具有核壳结构,这种复合粒子具有较高的稳定性。     

以SiO2纳米粒子为种子的甲基丙烯酸甲酯乳液聚合

本文采用SiO2纳米粒子作为种子进行了甲基丙烯酸甲酯的乳液聚合。初步探讨了此类种子乳液聚合的过程;也分析了SiO2的用量对所生成的残渣率的影响,SiO2在残渣中的实际含量均比在乳液聚合物中略高,这是由于总有一些单体转移到不含SiO2的自由胶束中进行聚合而造成的。所得的复合乳液聚合物的力学和热学性能测试结果表明材料的这两种性能均随SiO2含量的增加而降低。     

PMMA/BA无皂乳液聚合

以过硫酸铵为引发剂,用超声波引发PMMA/BA无皂乳液聚合;探讨了单体和引发剂的质量分数对单体转化率的影响,并对聚合物进行了FT-IR和TEM的表征。结果表明:PMMA/BA乳胶粒直径大约在100nm左右。     

MBS接枝共聚物对PMMA树脂的增韧研究

采用乳液聚合法在聚丁二烯（PB）乳胶粒子上接枝苯乙烯（St）和甲基丙烯酸甲酯(MMA),合成了一系列的MBS接枝共聚物（简称MBS）,将其与聚甲基丙烯酸甲酯（PMMA）进行熔融共混制备PMMA/MBS共混物,研究了PB及相对分子质量调节剂叔十二烷基硫醇（TDDM）含量对共混物力学性能和微观形态结构的影响。结果表明,随着MBS中PB所占比例的增加,共混物的冲击强度表现出先增大后减小的趋势,当PB所占比例为50 %（质量分数,下同）时,共混物的冲击强度达到200 J/m,而拉伸强度表现出上升的趋势;随着TDDM用量的增加,MBS的接枝率和接枝效率降低,导致共混物的冲击强度先增加后减小;随着MBS中PB所占比例的增加,接枝率的逐渐降低,MBS在PMMA基体中分散程度逐渐变差。     

悬浮聚合聚甲基丙烯酸甲酯／蒙脱土纳米复合材料的制备及表征

采用悬浮聚合法制备了聚甲基丙烯酸甲酯／蒙脱土（PMMA/MMT）纳米复合材料，利用X射线衍射仪、透射电子显微镜和傅里叶变换红外光谱等手段表征了复合材料的结构，研究了不同改性剂对复合材料结构的影响。通过热重分析考察了复合材料的热性能。结果表明，通过悬浮聚合可以成功制备剥离型纳米复合材料，PMMA基体与MMT可以产生较强的相互作用。MMT的加入可以显著提高复合材料的热稳定性。当MMT含量为10％（质量分数，下同）时，PMMA的最大分解温度提高了15℃。     

Morphological and mechanical characterization of a PMMA/CdS nanocomposite

Thick film of poly(methyl methacrylate) (PMMA)/CdS nanocomposite have been synthesized by the solution casting process. The nanostructure of the CdS particles has been ascertained through the small angle X-ray scattering (SAXS) technique. The surface morphological characterization of the PMMA/CdS nanocomposite has been done through scanning electron microscopy (SEM) analysis. The variation of mechanical loss factor (Tanδ) with temperature and tensile properties of prepared samples have been studied using Dynamic Mechanical Analyzer (DMA). This study reveals that the glass transition temperature (T_g), Young’s modulus, and fracture energy of the PMMA/CdS nanocomposite are greatly influenced by the existence of interfacial energetic interaction between dispersed CdS nanoparticles and the matrix of PMMA.     

基体组成对橡胶改性的PVC／PMMA共混物断裂行为的影响

通过种子乳液聚合方法合成聚丁二烯接枝甲基丙烯酸甲酯（PB-g-MMA）核-壳改性剂。将PB-g-MMA、聚氯乙烯（PVC）和聚甲基丙烯酸甲酯（PMMA）在160℃下熔融共混，制得橡胶含量为16％（质量含量）的一系列的橡胶改性PVC／PMMA共混物。研究了基体组成对共混物力学性能和形态结构的影响。结果表明在宽组成范围内PVC和PMMA是相容的，并且当PVC含量较少时，共混物以脆性方式断裂，银纹是其主要的形变机理；当PVC含量较多时，共混物以韧性方式断裂，此时主要的形变机理是橡胶粒子的空洞化和基体的剪切屈服。在橡胶改性PVC／PMMA共混物中，随着基体组成的改变形变，机理存在着从银纹到剪切屈服的转变。     

PMMA/MC复合胶粒的制备及在尼龙中的应用

采用原位乳液聚合法制备了聚甲基丙烯酸甲酯(PMMA)／三聚氰胺氰尿酸盐(MC)复合胶粒,对其进行X光电子能谱及热重分析结果显示,在MC阻燃剂颗粒表面覆盖了一层PMMA胶膜,形成了具有核-壳结构的PMMA／MC复合胶粒;MC能影响PMMA的热降解过程并促进其成炭;在尼龙6(PA6)中的应用结果表明,PMMA／MC复合胶粒能改善PA6的力学性能和阻燃性能。     

Thermal degradation behavior of PMMA synthesized by emulsifier‐free emulsion polymerization with a Cu2+/HSO3− redox system

In this study, poly(methyl methacrylate) (PMMA) latex was synthesized in an emulsifier‐free emulsion polymerization at 60°C using a Cu²⁺/HSO redox initiator system with different concentrations of Cu²⁺. The experimental results showed that the monomer conversion reached above 90% for all systems. Zeta potential was all negative due to the bonded bisulfite ion and the magnitude was greater than 30 mV, providing the stability of PMMA emulsion. The morphology of the latex observed by scanning electron microscope revealed a uniform particle size, and the average particle size increased from 181.9 to 234.2 nm as the Cu²⁺ ion concentration increased from 2.0 to 6.0 mM in 1M of MMA solution. Thermal degradation behavior of synthesized PMMA was studied by thermogravimetric analysis, in which a two‐stage degradation behavior was observed. These two stages were found to be caused by the degradation of unsaturated end group (PMMA? CR?CH₂) and saturated end group (PMMA? H), respectively. In addition, the higher the concentration of Cu²⁺ ion, the greater the proportion of PMMA? CR?CH₂ in the final product, and in turn rendering more weight loss in the first‐stage degradation. The copper ion not only played a role in the redox initiation, but also acted as a chain transfer agent to terminate growing polymer chains, thus producing PMMA? CR?CH₂. The apparent activation energies of the first stage (E_a1) and second stage (E_a2) were calculated by Ozawa's and Boswell's method. The results showed that E_a1, representing the degradation of PMMA‐CR?CH₂, was lower than E_a2 for the degradation of PMMA‐H. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

原位乳液聚合聚苯胺/聚甲基丙烯酸甲酯复合物及其表征

以DBSA为乳化剂和掺杂剂,在水介质中采用原位乳液聚合法制备出了聚苯胺/聚甲基丙烯酸甲酯(PANI/PMMA)复合物。采用扫描电镜、红外光谱分析、紫外光谱分析、热失重分析、X射线光电子能谱分析对PANI/PMMA复合物进行了表征。结果表明:复合物产物粒径在80～120nm;电导率可达到10-2S/cm,接近于乳液聚合得到的DBSA掺杂态PANI;乳化剂DBSA以掺杂剂和稳定剂两种状态存在于复合物中。     

Synthesis and properties of poly(methyl methacrylate)/montmorillonite (PMMA/MMT) nanocomposites

PMMA/MMT nanocomposites were successfully synthesized via in situ intercalative polymerization, and characterized by means of wide‐angle X‐ray diffractometry, transmission electron microscopy, thermal gravimetric analysis, dynamic mechanical analysis and Fourier‐transform infrared analysis. The nanocomposites possess partially exfoliated and partially intercalated structure, in which the silicate layers are exfoliated into nanometre secondary particles with thickness of less than 20 nm and uniformly dispersed in the polymer matrix. In comparison with pure PMMA, the thermal stability, glass transition temperature, and mechanical properties of the polymer are notably improved by the presence of the nanometric silicate layers. It was found that part of the PMMA chains in the nanocomposites are well immobilized inside and/or onto the layered silicates and, therefore, the unique properties of the nanocomposites result from the strong interactions between the nanometric silicate layers and the polymer chains. Copyright © 2003 Society of Chemical Industry