聚合物/LDH纳米复合材料的制备及其在涂料中的应用

LDH(层状双羟基氧化物)具有独特的结构优势、尺寸优势、性能优势,与高分子材料组装可得到聚合物/LDH纳米复合材料.重点阐述了聚合物/LDH纳米复合材料制备的最新研究进展,指出了该类材料在涂料工业等方面的应用前景.     

聚合物/氧化石墨纳米复合材料的研究进展

氧化石墨因具有层状结构,能够以插层复合的方式与聚合物形成聚合物纳米复合材料。本文介绍了氧化石墨的结构、性能特点以及聚合物/氧化石墨纳米复合材料的研究进展情况,包括聚合物/氧化石墨纳米复合材料的制备方法、种类、结构与性能特点、应用前景与研究展望。     

聚合物/层状矿物纳米复合材料的研究进展

聚合物/层状矿物纳米复合材料结合了聚合物的强韧性与纳米层状矿物的强力学性,具有优良的力学性能、热学性能、气体阻隔性能和导电性能等,实际应用广泛。介绍了聚合物/层状矿物纳米复合材料结构特点及其表征方法和制备方法、性能和应用,并综述了近年来聚合物/层状矿物纳米复合材料的研究进展,展望了该类材料的发展趋势。为了进一步加快该类材料的发展,应进一步从分子尺度上全面理解聚合物/层状矿物纳米复合材料的结构,尤其是聚合物主体与层状矿物片层间界面结构与性质对纳米复合材料整体性能的影响。     

聚合物/纳米SiO_2复合材料的研究进展

纳米SiO2 粒子具有许多新的特性 ,利用它对聚合物进行改性 ,可以得到具有特殊性能或性能更加优异的聚合物 /纳米SiO2 复合材料。介绍了纳米SiO2 特性、聚合物 /纳米SiO2 复合材料的制备方法以及我国聚合物 /纳米SiO2 复合材料的研究进展     

无卤阻燃水性聚氨酯的制备及性能研究

本文中研究了两种无卤阻燃剂,首先,层状双氢氧化物（LDH）具有独特的结构优势、尺寸优势、性能优势,与高分子材料组装可得到聚合物／LDH纳米复合材料,本实验中,采用共沉淀法合成了有机改性的LDH,通过XRD对其进行性能检测。其次,通过磷酸与三聚氰胺反应制备磷酸蜜胺盐（MPP）,并将其作为插层剂制备磷酸蜜胺盐．蒙脱土（MPM）,对蒙脱土进行了有机改性,用XRD对MPM的结构进行了分析表征。然后将有机改性的LDH和MPM按比例混合均匀,用研钵研碎,采用本体复合法制备WPU／OMT／LDH纳米复合材料,并测试了其氧指数。实验证明,这种混合阻燃剂对提高WPU的阻燃性能有良好的效果。     

聚丙烯/水滑石纳米复合材料制备及性能研究

针对聚合物/水滑石(LDH)纳米复合材料传统制备方法中存在的问题,采用球磨改性工艺制备聚丙烯(PP)/LDH纳米复合材料以期改进填充物在基体中的剥离和插层,重点研究了PP/LDH纳米复合材料的结构、力学性能。XRD分析表明,球磨工艺在对LDHs进行有机插层改性的同时实现了PP分子链的插层;所制备的PP/LDHs纳米复合材料其综合力学性能明显优于常规方法制备的复合材料。     

麦羟硅钠石/聚合物纳米复合材料研究进展

麦羟硅钠石（magadiite）是一种新型的层状纳米硅酸盐材料,由于其具有制备工艺简单、比表面积大、阳离子交换性能高、吸附性能强、层间膨胀性能好等优点,成为纳米材料提升聚合物性能最具有发展潜力的材料之一。本文主要综述了麦羟硅钠石/聚合物纳米复合材料的常用制备方法及其优缺点,包括聚合物插层法、单体原位插层聚合法、锚固插层聚合法。浅谈了国内外利用3种方法制备的基于聚苯乙烯、聚丙烯、环氧树脂、尼龙6、聚己内酯和聚甲基丙烯酸甲酯等多种聚合物的麦羟硅钠石/聚合物纳米复合材料,对在纳米复合材料结构中出现界面不相容、麦羟硅钠石分布不均匀的问题提出了解决方法,并阐述了麦羟硅钠石对纳米复合材料结构和性能的影响,最后展望了麦羟硅钠石/聚合物纳米复合材料的发展前景。     

聚合物/蒙脱土纳米复合材料研究进展

文章简要介绍了蒙脱土的结构,概述了聚合物/蒙脱土纳米蒙脱土材料的结构及性能,详细介绍了聚丙烯(PP)/蒙脱土、聚乙烯(PE)/蒙脱土、环氧树脂(EP)/蒙脱土纳米复合材料国内外最新的研究进展,叙述了聚合物/蒙脱土纳米复合材料优良的力学性能和热学性能。最后对聚合物/蒙脱土纳米复合材料的未来发展做了预测。     

聚合物/LDH复合材料的制备及阻燃性能研究进展

水滑石(LDH)是一类典型的阴离子型层状材料,具有优异的阻燃性和热稳定性,且低烟、低毒、环境友好。将其与聚合物制备复合材料,可以显著提升聚合物的耐火能力,因而受到研究者的广泛关注。介绍了LDH的结构特点及其有机改性方法,包括离子交换法、煅烧还原法、一步法和溶剂剥离法。总结了常用于制备聚合物/LDH复合材料的方法,并简述了其优缺点。重点综述了影响聚合物/LDH复合材料阻燃性的因素,主要包括LDH板层二价和三价阳离子、多金属阳离子的引入和改性剂等方面的影响;简述了其他阻燃材料配合LDH协同阻燃的进展。最后,分析了阻燃型聚合物/LDH复合材料的研究现状,就该材料在产业化推广、进一步提升高效阻燃性能、明确阻燃机理等方面提出了观点。     

聚合物/LDH纳米复合材料的制备及其阻燃性的研究进展

水滑石（LDH）是一类典型的阴离子型层状材料，具有优异的阻燃性和热稳定性，且低烟、低毒、环境友好。将其与聚合物复合制备复合材料，可以显著提升聚合物的耐火能力，因而受到研究者的广泛关注。本文介绍了LDH的结构特点及其有机改性方法，包括离子交换法、煅烧还原法、一步法和溶剂剥离法。总结了常用于制备聚合物/LDH复合材料的方法，并简述了它们各自的优缺点。重点综述了影响聚合物/LDH复合材料阻燃性的因素，主要包括LDH板层二价和三价阳离子、多金属阳离子的引入和改性剂等方面的影响；简述了其他阻燃材料配合LDH协同阻燃的进展。最后，笔者分析了阻燃型聚合物/LDH复合材料的研究现状，就该材料在产业化推广、进一步提升高效阻燃性能、明确阻燃机理等方面，提出了自己的观点。     

Preparation and properties of exfoliated nanocomposites through intercalated a photoinitiator into LDH interlayer used for UV curing coatings

The exfoliated polymer/layered double hydroxide (LDH) nanocomposites based on MgAl were prepared through intercalating a photoinitiator into LDH interlayer, following by UV irradiation induced polymerization. The fragmental photoinitiator, 2-hydroxy-2-methyl-1-phenylpropane-1-one (1173) firstly reacted with isophorone diisocyanate (IPDI) to obtain the semiadduct, 1173-IPDI, and then reacted with the LDH modified by aminoundecanoic acid, obtaining LDH-1173 with an intercalated microstructure, which was characterized by FTIR, XRD, and TGA measurements. The obtained LDH-1173 was mixed with the multifunctional acrylate oligomer and monomer, and then exposed to a UV lamp to prepare a polymer/LDH nanocomposite. From the XRD, TEM and HR-TEM analysis, as well the photopolymerization kinetics investigation, it was found that the LDH-1173 effectively initiated the photopolymerization of acrylates, and formed exfoliated polymer/LDH nanocomposites. However, the mostly intercalated polymer/LDH nanocomposites were obtained for the systems with additional 1173 except for LDH-1173 addition. Compared with the pure polymer material, both the exfoliated and intercalated polymer/LDH nanocomposites exhibited the enhancements in mechanical and thermal properties, as well as hardness.     

Exfoliated polymer nanocomposites by in situ coprecipitation of layered double hydroxides in a polymer matrix

Polyvinylalcohol (PVA) nanocomposites were prepared by a “one step” method based on the coprecipitation of layered double hydroxide (LDH) platelets in the polymer aqueous solution. The PVA/LDH nanocomposites displayed an exfoliated morphology and the concentration of LDH in the nanocomposite was evaluated by IR analysis. Moreover, it was shown that the PVA/LDH nanocomposites had an improved photostability over PVA, which makes this material a good candidate for coating applications. Further optimization will be considered to tune the polymer/LDH properties. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

水滑石(LDH)的合成及其表征

利用“双滴法”成功制备出具有层状结构的镁铝水滑石,并对比确定了最佳反应温度。首先在50℃、80％、95％下制备出三种水滑石,利用XRD分析水滑石的结构,确认制备出了具有典型层状结构的水滑石;然后利用TGA测试三种水滑石的热分解温度,发现95℃下制备出的水滑石晶体强度较高,为进一步研究聚合物基水滑石纳米复合材料奠定了良好的基础。     

Functionalized polyvinyl chloride/layered double hydroxide nanocomposites and its thermal and mechanical properties

In this work, to inquire the impact of layered double hydroxide (LDH) nanoclay on functionalized poly(vinyl chloride) (PVC) through solution intercalation method, four kinds of nanocomposites were prepared. Mg-AL LDH and the obtained functionalize PVC composites were characterized through FT-IR, UV–Vis spectroscopy, TEM, XRD, contact angle, DSC, and UTM. Obtained results revealed that the functionalized PVC uniformly dispersed in the layer of LDH nanoclay. It is revealed that partially intercalated and disordered structure formed in PVC/LDH, PVC-TS (thiosulfate)/LDH, and PVC-S (sulfate)/LDH nanocomposites, whereas fully exfoliated structures formed in the PVC-TU (thiourea)/LDH nanocomposites. Further, it has been observed that the ultimate tensile strength for all the polymer nanocomposites enhanced with increased in the LDH content. These nanocomposites further exhibited higher thermal stability by at least by 51°C higher than the pristine PVC. Along with these, further it has been found that the functionalized PVC/LDH nanocomposites are proved to be effective as thermal stabilizer for PVC processing. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48894.     

Delamination of organo-modified layered double hydroxides in polyamide 6 by melt processing

Layered double hydroxides (LDH) are a class of readily synthesizable layered crystals that can be used as an alternative to the commonly used silicate crystals for the preparation of polymeric nanocomposites. In this work layered double hydroxide/polyamide 6 nanocomposites (LDH/PA6) were prepared from organo-modified LDH by melt processing. The anionic exchange capacity of LDH was varied in order to investigate its influence on the degree of exfoliation. LDH were dispersed by a twin screw micro-extruder at a variety of processing conditions. The nanocomposites were characterized by wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), transmission electron microscopy, dynamic scanning calorimetry, and thermogravimetric analysis. It was found that exfoliated nanocomposites were successfully prepared by melt processing with a low exchange capacity LDH, whereas residue tactoids were observed with a high exchange capacity LDH. Shear, together with the exchange capacity, seems to be the key factor for the delamination in LDH/PA6. No major change in the crystalline phase or in the rate of crystallization was observed in the nanocomposite as compared to the neat polymer. A reduction in the onset of thermal decomposition temperature was observed in PA6/LDH compared to neat PA6, likely due to a nucleophilic attack mechanism. The properties of this nanocomposite system are discussed with connections to the current understanding within the broader nanocomposite field.     

Ethylene vinyl acetate/ethylene propylene diene terpolymer‐blend‐layered double hydroxide nanocomposites

Ethylene vinyl acetate (EVA‐45)/ethylene propylene diene terpolymer (EPDM) blend‐layered double hydroxide (LDH) nanocomposites have been prepared by solution blending of 1:1 weight ratio of EVA and EPDM with varying amounts of organo LDH (DS‐LDH). X‐ray diffraction and transmission electron microscopy analysis suggest the formation of partially exfoliated EVA/EPDM/DS‐LDH nanocomposites. Measurement of mechanical properties of the nanocomposites (3 wt% DS‐LDH content) show that the improvement in tensile strength and elongation at break are 35 and 12% higher than neat EVA/EPDM blends. Dynamic mechanical thermal analysis also shows that the storage modulus of the nanocomposites at glass transition temperature is higher compared to the pure blend. Such improvements in mechanical properties have been correlated in terms of fracture behavior of the nanocomposites using scanning electron microscopy analysis. Thermal stability of the prepared nanocomposites is substantially higher compared to neat EVA/EPDM blend, confirming the formation of high‐performance polymer nanocomposites. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Preparation and characterization of exfoliated layered double hydroxide/silicone rubber nanocomposites

Silicone rubber (SR)/Mg–Al layered double hydroxide (LDH) nanocomposites were prepared by the solution intercalation of SR crosslinked by a platinum‐catalyzed hydrosilylation reaction into the galleries of dodecyl sulfate intercalated layered double hydroxide (DS–LDH). X‐ray diffraction and transmission electron microscopy analysis showed the formation of exfoliated structures of organomodified LDH layers in the SR matrix. The tensile strength and elongation at break of SR/DS–LDH (5 wt %) were maximally improved by 53 and 38%, respectively, in comparison with those of the neat polymer. Thermogravimetric analysis indicated that the thermal degradation temperature of the exfoliated SR/DS–LDH (1 wt %) nanocomposites at 50% weight loss was 20°C higher than that of pure SR. Differential scanning calorimetry analysis data confirmed that the melting temperature of the nanocomposites increased at lower filler loadings (1, 3, and 5 wt %), whereas it decreased at a higher filler loading (8 wt %). The relative improvements in the solvent‐uptake resistance behavior of the SR/DS–LDH nanocomposites were also observed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

In situ microwave‐assisted polymerization of polyethylene terephtalate in layered double hydroxides

The synthesis of poly(ethylene terephthalate) (PET)/layered double hydroxide (LDH) nanocomposites through microwave methods has been investigated. To enhance the compatibility between the PET polymer and the LDH, dodecyl sulfate was intercalated in the lamellar structure. The organo‐LDH structure was confirmed by powder X‐ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR). PET nanocomposites were prepared with 0–10 wt % of LDH content by in situ microwave‐assisted polymerization. PXRD was used to detect the formation of the exfoliated PET/LDH nanocomposites. Transmission electron microscopy was used to observe the dispersed layers and to confirm the exfoliation process. FTIR spectroscopy confirmed that the polymerization process had occurred. TG and DTA are used to study changes in thermal stability of the nanocomposites, which resulted enhanced by well dispersed LDHs layers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of bilayered stearate ion‐modified Mg?Al layered double hydroxide on the thermal and mechanical properties of silicone rubber nanocomposites

The homogeneous dispersion of nanofillers in polymer matrices to form polymer nanocomposites remains a challenge in the development of high‐performance polymer materials for various applications. In the work reported, a stearate ion‐modified Mg? Al layered double hydroxide (St‐LDH) as nanofiller was incorporated in a silicone rubber (SR) matrix by solution intercalation and subsequently characterized. X‐ray diffraction and transmission electron microscopy studies confirm the formation of a predominantly exfoliated dispersion of St‐LDH layers of 75–100 nm in width and about 1–2 nm in thickness in the SR. Thermogravimetric analysis shows that the thermal degradation temperature of the exfoliated SR/St‐LDH (1 wt%) nanocomposites is about 80 °C higher than that of pure SR. Differential scanning calorimetric studies indicate that the melting and crystallization temperatures are higher by 4 and 10 °C for 5 and 8 wt% St‐LDH‐loaded SR nanocomposites compared to neat SR. A significant improvement of 97% in tensile strength and 714% in storage modulus and a reduction of 82% in oxygen permeability have been achieved at 3 wt% St‐LDH loading in SR. Copyright © 2011 Society of Chemical Industry     

Preparation of waterborne hyperbranched polyurethane acrylate/LDH nanocomposite

A series of novel waterborne hyperbranched polyurethane acrylate (WHPUA)/layered double hydroxide (LDH) nanocomposites based on hyperbranched aliphatic polyester Boltorn H20 (H20) and MgAl-LDH were successfully synthesized by in situ polymerization approach. The MgAl-LDH was firstly modified by sodium dodecyl sulfate (SDS) through the coprecipitation method, and then grafted by isophorone diisocyanate (IPDI), forming a complex with NCO groups at the surface and interlayer of LDH (LDH-DS-NCO). The residual hydroxyl groups after modification with succinic anhydride were crosslinked by the semi-adduct of IPDI reacted with HEA, and LDH-DS-NCO, followed by a neutralization reaction with triethylamine. The resulting water dispersible hyperbranched polyurethane acrylate WHPUA/LDH hybrid oligomer was then exposed to a medium pressure mercury lamp, forming a partially exfoliated WHPUA/LDH nanocomposite in the presence of a fragmental photoinitiator. The chemical structure, crystal configuration, morphology of WHPUA/LDH nanocomposite were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and high resolution transmission electron microscopy. The experimental results indicated that both the intercalated and exfoliated structures were formed in the UV cured polymer/LDH nanocomposite. The TGA results showed that the thermal stability was improved. Moreover, the pencil hardness was greatly increased, and the flexibility remained at an acceptable level for the UV cured polymer/LDH nanocomposites.