ACR-g-VC/纳米水滑石复合材料的形态及性能

采用原位悬浮聚合制备了丙烯酸酯共聚物(ACR)接枝氯乙烯(VC)(ACR-g-VC)树脂和ACR-g-VC/纳米水滑石复合材料,并研究了复合材料的形态、加工塑化性能、力学和热性能。采用原位聚合/熔融加工得到的ACR-g-VC/纳米水滑石复合材料中,纳米水滑石基本以初级粒子形式存在,分散性明显优于由ACR-g-VC与纳米水滑石直接熔融共混制备的复合材料。水滑石含量对原位聚合/熔融加工得到的ACR-g-VC/纳米水滑石复合材料的简支梁缺口冲击强度和储能模量影响较小,而ACR-g-VC的热稳定和加工塑化性能随纳米水滑石的引入而提高。水滑石质量分数为2%的复合材料质量损失10%的温度比聚氯乙烯提高近20℃,而塑化时间缩短至22 s。     

乙烯-丙烯酸共聚物原位接枝木粉及其对HDPE/木粉复合材料性能影响研究

采用一步法制备了高密度聚乙烯(HDPE)/乙烯-丙烯酸共聚物(EAA)原位接枝木粉复合材料,并研究了EAA含量、木粉含量和不同丙烯酸(AA)含量的EAA对HDPE/木粉复合材料拉伸和弯曲性能的影响规律。在HDPE/木粉复合材料熔融混合过程中,在热和剪切力的作用下,EAA分子链上的—COOH与木粉(WF)表面的—OH发生化学反应,实现了对木粉的原位接枝,提高了木粉与HDPE的相容性,从而提高了HDPE/木粉复合材料的拉伸和弯曲性能。采用傅里叶变换红外光谱(FTIR)和热失重分析(TG)表征了EAA对木粉的原位接枝,并采用高低温双立柱试验机研究了HDPE/木粉复合材料的拉伸、弯曲性能。研究表明,EAA在HDPE/木粉复合材料的熔融制备过程中成功地接枝到了木粉表面,提高了木粉与HDPE的相容性及HDPE/木粉的拉伸和弯曲强度。     

尼龙6/水滑石纳米复合材料的制备与表征

利用熔融插层复合法制备了插层型尼龙6／水滑石纳米复合材料。Ⅺ砌分析了水滑石的结构,确认成功制备出了具有典型层状结构的水滑石。利用透射电子显微镜（TEM）观察水滑石在尼龙6基体中的分散,确认制备出了插层型的纳米复合材料。对纳米复合材料的力学性能测试结果表明：加入水滑石之后,材料的屈服强度、定伸强度及拉伸模量都有明显提高,而且冲击强度基本不变。其中2号水滑石与尼龙6复合后拉伸模量与尼龙相比提高了26．8％。DSC和TGA测试结果显示,由于水滑石的存在对纳米复合材料的结晶性能和热稳定性略有影响。     

加工方式对PP/EAA/LDH复合材料性能影响

进行了聚丙烯(PP)、乙烯–丙烯酸共聚物(EAA)及水滑石(LDH)复合材料改性一体化研究,并研究了一次熔融挤出加工法和二次熔融挤出加工法对PP复合材料性能的影响。X射线多晶衍射、透射电子显微镜分析表明:两种加工方法制备的复合材料中EAA均插层和剥离了LDH,改善了LDH在PP基体中分散性,并且一次挤出加工效果优于二次挤出加工效果;热失重分析表明,两种加工方式均提高了复合材料的热稳定性能;静态力学性能测试表明:一次挤出加工制备的复合材料PP1的拉伸强度、拉伸弹性模量和缺口冲击强度均高于二次挤出加工制备的复合材料PP2。实验表明一次熔融挤出加工方法对复合材料中LDH插层和剥离效果以及LDH在PP基体中分散效果优于二次熔融挤出加工。     

反应性相容剂的制备及其在PP/玻璃纤维复合材料中的应用

以马来酸酐(MAH)为接枝单体、丙烯酸-2-羟乙酯为共聚单体,利用熔融接枝技术对聚丙烯(PP)进行改性;以MAH/丙烯酸-2-羟乙酯熔融接枝改性PP为相容剂,研究相容剂对PP/玻璃纤维复合材料结构和性能的影响。结果表明:与未接枝PP相比,熔融接枝PP分子上接枝了MAH和—OH基团,而且熔融接枝反应对PP的熔点和热稳定性具有明显影响。另外,随着接枝PP含量的增加,PP/玻璃纤维复合材料的力学性能明显改善。当接枝PP含量为15%时,复合材料的拉伸强度提高了32%,冲击强度提高了13%,表明采用熔融共接枝工艺制备的PP具有优良的增容、偶联和分散效果。     

POE-g-MAH对PA66/纳米TiO_2复合材料力学性能及相容性的影响

采用熔融共混法制备了尼龙(PA)66/马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)/纳米TiO2复合材料,通过万能材料试验机、冲击试验机、熔体流动速率(MFR)测试仪等研究了POE-g-MAH对复合材料力学性能及MFR的影响,利用Molau实验和FSEM考察了POE-g-MAH与PA66的相容性。结果显示,POE-g-MAH与PA66基体有很好的相容性;随着POE-g-MAH用量的增加,PA66/POE-g-MAH/纳米TiO2复合材料的缺口冲击强度逐渐增加,拉伸强度、弯曲强度、拉伸弹性模量及MFR逐渐降低;当POE-g-MAH质量分数为12%时,复合材料的综合性能最佳,缺口冲击强度、拉伸强度、弯曲强度、拉伸弹性模量和MFR分别为20.89kJ/m2,41.15MPa,64.2MPa,1428.15MPa和19.2g/(10min)。     

聚烯烃／蒙脱土复合材料的制备与阻氧性能研究

本文以乙烯-辛稀共聚物（PE—R）、无规共聚物（PP—R）、聚丁烯（PB）、聚丙烯接枝马来酸酐共聚物（PP—g—MAH）与有机蒙脱土（OMMT）。通过熔融共混制备了聚合物／蒙脱土复合材料体系。测试了各体系的熔体质量流动速率（MFR）、熔点、维卡软化点、力学性能、氧气透过率。结果表明添加了20％有机蒙脱土的复合材料的的熔体质量流动速率与未添加的相比大幅度下降,熔点和维卡软化点略有上升,力学性能与未添加的相比出现下降。添加了20％有机蒙脱土的复合材料阻氧性能与未添加的相比有所提高。     

纳米SiO_2改性ABS回料性能研究

采用熔融共混的方法制备高胶粉/丙烯腈-丁二烯-苯乙烯共聚物(ABS)/纳米二氧化硅多元增韧复合材料。对复合材料结构、冲击强度、拉伸性能及熔体流动性能进行表征。结果表明:适量纳米二氧化硅刚性粒子在共混体系中均匀分散可提供补强效果,并且不影响体系的流动性,不会破坏共混体系结构。当纳米二氧化硅添加量为0.5 phr时,复合材料综合性能达到最佳,增韧效果最好,冲击强度提高30%以上。     

增容剂对竹粉/HDPE复合材料力学性能及流变性能的影响

分别以马来酸酐接枝聚乙烯(MAPE)、马来酸酐接枝聚乙烯-辛烯共聚物(MAPOE)和乙烯-丙烯酸共聚物(EAA)为相容剂,通过熔融共混方法制备高密度聚乙烯(HDPE)/竹粉复合材料。采用万能材料试验机、维卡软化点测量仪和旋转流变仪对该共混物力学性能和流变性能进行详细研究。结果表明,MAPE对竹粉/HDPE复合材料具有很好的增容效果:加入10%MAPE时,复合材料的拉伸强度达到33.3 MPa,提高了50.8%;弯曲强度为46.3MPa,提高了20.0%;缺口冲击强度达到10.22 kJ/m2,提高了95.0%,同时吸水率也得到改善,从0.71%下降至0.62%。流变实验结果表明,MAPE和EAA增容竹粉/HDPE复合材料的黏度较低,而MAPOE体系黏度较高,加工性能变差。     

纳米水滑石对PVC热稳定性和烟密度的影响

研究了纳米水滑石（nano—HT）对聚氯乙烯（PVC）热稳定性和燃烧烟密度的影响。采用原位聚合并熔融加工得到PVC／纳米水滑石复合材料，纳米水滑石在PVC基体中分散均匀，分散尺度小于100nm。随着纳米水滑石含量增加，PVC／nano—HT复合材料的热分解温度和刚果红变色时间增加，热稳定性提高；分散均匀的纳米水滑石对PVC具有良好的抑烟效果，当PVC／nano—HT复合材料中纳米水滑石含量为1．25％和2．5％时，最大烟密度分别比空白PVC低40％和60％左右。     

环氧树脂/水滑石纳米复合材料的研究进展

介绍了水滑石的结构、性能、制备方法及环氧树脂/水滑石纳米复合材料的制备方法;指出与环氧复合材料相比,环氧树脂/水滑石纳米复合材料具有良好的阻燃性能和抑烟效果,应用前景广阔.     

Preparation and Properties of ZnAl Layered Double Hydroxide/Polycaprolactone Nanocomposites for Use in Drug Delivery

ZnAl-layered double hydroxides (ZnAl-LDH)/polycaprolactone (PCL) nanocomposites were prepared by solution intercalation method. It is shown that lamellar ZnAl-LDH is randomly distributed in the PCL matrix with diameter of 60 nm. The addition of ZnAl-LDH decreases thermal decomposition temperature of composites, but improves the elastic modulus and tensile strength. The weight loss and release amount of diclofenac of ZnAl-LDH/PCL composites are higher than that of neat PCL. The drug release kinetics for nanocomposites and neat PCL could be described by first-order kinetic and Ritger-Peppas kinetic model.     

丙烯腈-苯乙烯磺酸共聚物/层状双金属氢氧化物纳米复合质子传导聚合物电解质的制备与表征

Acrylonitrile-sodium styrene sulfonate copolymer/layered double hydroxides nanocomposites were prepared by in situ aqueous precipitation copolymerization of acrylonitrile （AN） and sodium styrene sulfonate （SSS） in the presence of 4-vinylbenzene sulfonate intercalated layered double hydroxides （MgA1-VBS LDHs） and transferred to acrylonitrile-styrene sulfonic acid （AN-SSA） copolymer/LDHs nanocomposites as a proton-conducting polymer electrolyte. MgA1-VBS LDHs were prepared by a coprecipitation method, and the structure and composition of MgAl-VBS LDHs were determined by X-ray diffraction （XRD）, infrared spectroscopy, and elemental analysis. X-ray diffraction result of AN-SSS copolymer/LDHs nanocomposites indicated that the LDHs layers were well dispersed in the AN-SSS copolymer matrix. All the AN-SSS copolymer/LDHs nanocomposites showed significant enhancement of the decomposition temperatures compared with the pristine AN-SSS copolymer, as identified by the thermogravimetric analysis. The methanol crossover was decreased and the proton conductivity was highly enhanced for the AN-SSA copolymer/LDHs nanocomposite electrolyte systems. In the case of the nanocomposite electrolyte containing 2% （by mass） LDHs, the proton conductivity of 2.60×10^- 3 S·m^-1 was achieved for the polymer electrolyte.     

Preparation and properties of LDHs/polyimide nanocomposites

Layered double hydroxides/polyimide (LDHs/PI) nanocomposites were prepared from solution of polyamic acid (polyimide precursor) and LDH-amino benzoate using N,N-dimethylacetamide as a solvent. LDH-amino benzoate (LDH-AB) was obtained by coprecipitation method. The amino benzoate, grafted on the surface of the Mg/Al nanolayers, as a connector improved the compatibility between the inorganic Mg/Al nanolayers and the organic polyimide molecules. The dispersion behavior of Mg/Al nanolayers was investigated by transmission electron microscopy and X-ray diffraction, indicating that the Mg/Al nanolayers were exfoliated in PI matrix to form LDH-AB/PI nanocomposites. The maximum tensile strength and elongation of the LDH-AB/PI nanocomposites were found with the LDH-AB content of 5 and 4 wt%, respectively. The initial tensile modulus of these nanocomposites was increased with the LDH-AB content. These nanocomposites exhibited higher storage and loss moduli compared to those of pure PI. T_g of these nanocomposites increased with the LDH-AB content. Coefficients of thermal expansion (CTE, below and above T_g) of these nanocomposites deceased with the LDH-AB content. The thermal properties of these nanocomposites were enhanced by the incorporation of Mg/Al nanolayers in PI matrix.     

凹凸棒土反应填充HDPE制备纳米复合材料

在凹凸棒土表面吸附马来酸酐(MAH)单体和过氧化二异丙苯(DCP)引发剂，将处理过的凹凸棒土填充HDPE，制备HDPE／凹凸棒土纳米复合材料。结果表明，纳米复合材料的拉伸和冲击性能都有所提高，其中冲击性能提高了50％左右；用FT—IR，XRD，TEM等方法，对HDPE／凹凸棒土纳米复合材料的结构进行表征研究。     

The influence of carbon nanotubes, organically modified montmorillonites and layered double hydroxides on the thermal degradation and fire retardancy of polyethylene, ethylene-vinyl acetate copolymer and polystyrene

Nanocomposites of polyethylene, ethylene-vinyl acetate copolymer and polystyrene with single- and multi-wall carbon nanotubes, organically modified montmorillonites and layered double hydroxides were prepared by melt blending. Their morphologies were assessed by X-ray diffraction and transmission electron microscopy, while the flammability properties were evaluated by thermogravimetric analysis and cone calorimetry. The relative amounts and the identity of the degradation products are changed when both well-dispersed cationic and anionic clays are used, but there is no difference in the degradation products when carbon nanotubes were utilized. When the nano-dimensional material is not well-dispersed, the degradation products are not changed. Unlike their smectite counterparts, polymer/layered double hydroxide nanocomposites give reasonably good reductions in peak heat release even when good nano-dispersion has not been obtained. These data suggest that the enhancement in the fire behavior must be, at least in part, due to different mechanisms for montmorillonite, layered double hydroxides and carbon nanotube-based nanocomposites.     

聚合物-层状双氢氧化物纳米复合材料的研究进展

综述了以聚合物为基体的聚合物-层状双氢氧化物(LDHs)纳米复合材料在阻燃材料中应用的研究进展,重点阐述了LDHs的层状结构、改性以及聚合物-LDHs纳米复合材料的制备,并介绍了当前国内外各类关于聚合物-LDHs纳米复合材料的阻燃研究应用,对其今后的发展提出了展望。     

In vitro inhibition of histamine release behavior of cetirizine intercalated into zn/al- and mg/al-layered double hydroxides

The intercalation of cetirizine into two types of layered double hydroxides, Zn/Al and Mg/Al, has been investigated by the ion exchange method to form CTZAN and CTMAN nanocomposites, respectively. The basal spacing of the nanocomposites were expanded to 31.9 Å for CTZAN and 31.2 Å for CTMAN, suggesting that cetirizine anion was intercalated into Layered double hydroxides (LDHs) and arranged in a tilted bilayer fashion. A Fourier transform infrared spectroscopy (FTIR) study supported the formation of both the nanocomposites, and the intercalated cetirizine is thermally more stable than its counterpart in free state. The loading of cetirizine in the nanocomposite was estimated to be about 57.2% for CTZAN and 60.7% CTMAN. The cetirizine release from the nanocomposites show sustained release manner and the release rate of cetirizine from CTZAN and CTMAN nanocomposites at pH 7.4 is remarkably lower than that at pH 4.8, presumably due to the different release mechanism. The inhibition of histamine release from RBL2H3 cells by the free cetirizine is higher than the intercalated cetirizine both in CTZAN and CTMAN nanocomposites. The viability in human Chang liver cells at 1000 μg/mL for CTZAN and CTMAN nanocomposites are 74.5 and 91.9%, respectively.     

The Polymerization of Unsaturated Polyester and Silane-Functionalized Layered Double Hydroxides

The preparation of surface-modified layered double hydroxides/unsaturated polyester (LDH/UP) nanocomposites were performed. By in situ coprecipitation, LDHs, modified through grafting of vinyltriethoxysilane (VTS) carrying a double bond using the anionic surfactant sodium dodecyl sulfate (SDS), were used as nanofillers for unsaturated polyester (UP). The morphology of LDH and nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscope (TEM). Moreover, the thermal properties were determined by thermogravimetric analysis (TGA) and thermal degradation mechanism was discussed.     

Preparation and properties of LDHs/epoxy nanocomposites

Layered double hydroxides (LDHs)/epoxy nanocomposites were prepared by mixing the amino laurate intercalated LDHs, EPON 828 resin, and Jeffamine D400 as a curing agent. The organo-modified LDHs with hydrophobic property easily disperse in epoxy resin, and the amino laurate intercalated LDHs with large gallery space allow the epoxy molecules and the curing agents to easily diffuse into the LDHs galleries at elevated temperature. After the thermal curing process, the exfoliated LDHs/epoxy nanocomposites were formed. X-ray diffraction was used to detect the formation process of the exfoliated LDHs/epoxy nanocomposites. TEM was used to observe the dispersed behavior of the LDHs nanolayers, and the LDHs nanolayers were exfoliated and well dispersed in these nanocomposites. Owing to the reaction between the amine groups of the intercalated amino laurate and epoxy groups, the adhesion between the LDHs nanolayers and epoxy molecules makes these LDHs/epoxy nanocomposites more compatible. Consequently, the tensile properties from tensile test and the mechanical properties from DMA were enhanced, and the T_g of these nanocomposites from DMA and TMA were increased. Coefficients of thermal expansion (CTEs, below and above T_g) of these nanocomposites from TMA decreased with the LDHs content. The thermal stability of these nanocomposites was enhanced by the well dispersed LDHs nanolayers.