聚氯乙烯/层状双氢氧化物纳米复合材料研究进展

聚氯乙烯(PVC)/层状双氢氧化物(LDHs)纳米复合材料相比于纯聚氯乙烯具有更好的热稳定性、力学性能、阻燃抑烟性、耐候性与耐光性等,是一种性能优异并具有广泛应用前景的新型聚合物基纳米复合材料。本文首先介绍了LDHs的化学组成和结构特点,并对其制备过程和性质特点进行了分析和探讨;然后综述了PVC/LDH纳米复合材料的制备、结构表征及性能等方面的最新研究进展,重点阐述了LDHs的表面有机化处理及其对PVC/LDH纳米复合材料制备与性能的重要作用;最后对其应用前景进行展望。     

聚丙烯酰胺/层状无机物纳米复合材料研究进展

聚丙烯酰胺(PAM)/层状无机物纳米复合材料相比于纯PAM具有更好的力学性能、超吸水性能、热稳定性能和气体阻隔性能等,是一种性能优异并在采油、农业和卫生学等领域有着广泛应用前景的新型聚合物基纳米复合材料。本文对近年来聚丙烯酰胺/层状无机物纳米复合材料的研究进展进行了综述。首先重点介绍了层状双氢氧化物(LDHs)在有机溶剂和水中剥离分散方面的研究进展,接着综述了PAM/LDH和PAM/粘土纳米复合材料的制备与结构表征,最后阐述了PAM/层状无机物纳米复合材料的流变性能、力学性能和超吸水性能等。     

聚丙烯/层状双氢氧化物纳米复合材料研究进展

聚丙烯/层状双氢氧化物纳米复合材料是近年来开发的新型聚合物基复合材料,具有与纯聚合物基体不同的结晶行为,而且表现出优异的机械力学性能、耐热性能、阻燃性能和耐紫外线功能等,有着广泛的应用前景。本文首先对层状双氢氧化物的结构、组成与制备方法进行简要介绍,然后重点阐述了聚丙烯/层状双氢氧化物纳米复合材料的制备、分散结构表征、结晶行为以及力学和热学等性能方面的研究进展,最后对其应用前景进行展望。     

纳米二氧化钛的制备、修饰及其在PET中的应用研究进展北大核心CSCD

纳米二氧化钛(TiO2)具有粒径小、比表面积大、紫外屏蔽能力强、催化活性高等特点,近年来,纳米TiO2在聚对苯二甲酸乙二醇酯(PET)中的应用成为研究热点。本文介绍了纳米TiO2的结构特点、不同形态纳米TiO2的制备方法和纳米TiO2的表面修饰技术,讨论了纳米TiO2的特性和含量对PET结晶和力学性能的影响,总结了PET/纳米TiO2复合材料的防紫外线和抗老化性能。同时,还综述了利用TiO2的光催化作用制备具有催化、杀菌、防臭和自清洁等功能的PET/纳米TiO2复合材料的研究进展,并对纳米TiO2在PET中的应用进行了展望。     

纳米二氧化钛的制备、修饰及其在PET中的应用研究进展

纳米二氧化钛(TiO2)具有粒径小、比表面积大、紫外屏蔽能力强、催化活性高等特点,近年来,纳米TiO2在聚对苯二甲酸乙二醇酯(PET)中的应用成为研究热点。本文介绍了纳米TiO2的结构特点、不同形态纳米TiO2的制备方法和纳米TiO2的表面修饰技术,讨论了纳米TiO2的特性和含量对PET结晶和力学性能的影响,总结了PET/纳米TiO2复合材料的防紫外线和抗老化性能。同时,还综述了利用TiO2的光催化作用制备具有催化、杀菌、防臭和自清洁等功能的PET/纳米TiO2复合材料的研究进展,并对纳米TiO2在PET中的应用进行了展望。     

聚乙烯醇/层状双氢氧化物纳米复合材料研究进展

聚乙烯醇/层状双氢氧化物纳米复合材料是近年来开发的新型聚合物基复合材料,表现出与纯聚乙烯醇基体明显不同的结晶行为,且具有良好的机械力学性能、耐热性能以及阻燃性能等,有着广泛的应用前景。本文首先对层状双氢氧化物的结构组成、制备方法和性质进行简要综述,然后着重介绍聚乙烯醇/层状双氢氧化物纳米复合材料的制备、结构表征、结晶行为、力学和热性能等方面的研究进展,最后对其应用前景进行展望。     

金属氢氧化物直接制备对苯二甲酸插层水滑石及其应用

以新制备的Mg(OH)_2和Al(OH)_3滤饼与对苯二甲酸通过水热反应制备了对苯二甲酸插层水滑石(TALDHs).使用X射线衍射(XRD)、热重-差热分析、扫描电镜(SEM)等技术对TA-LDHs与碳酸根型水滑石(CO3-LDHs)进行对比研究,结果显示,对苯二甲酸离子成功插入到LDHs层间,产物结构完整、晶相单一,所制得的TA-LDHs为片状.CO3-LDHs和TA-LDHs分别作为纳米填料,以两种不同的添加方式制备聚对苯二甲酸乙二醇酯(PET)/LDHs纳米复合材料.对复合材料进行XRD和SEM研究,结果表明在酯交换反应前添加2%TA-LDHs所制备的PET/LDHs纳米复合材料的层板被部分剥离,分散性最好.     

聚合物／层状硅酸盐纳米复合材料研究进展

聚合物／层状硅酸盐（ＰＬＳ）纳米复合材料是近１０年迅速发展起来的研究交叉科学。由于聚合物纳米复合材料具有常规聚合物复合材料所没有的结构、形态以及较常规聚合物复合材料更优异的物理力学性能、耐热性和气体液体阻隔性能等,因而显示出重要的科学意义和应用前景。本文综述了聚合物／层状硅酸盐纳米复合材料的制备,结构表征和物理力学性能,对制务过程进行了热力学和动力学分析,最后对其应用前景进行了展望。     

石墨烯及其聚合物复合材料

近些年来,石墨烯以其独特的结构和优异的性质成为备受瞩目的研究前沿和热点。石墨烯作为纳米增强组分,少量添加可以使聚合物的物理性能得到大幅地提高。本文就石墨烯及其在聚合物复合材料的研究进展进行了综述,着重阐述了现已工业化制备石墨烯的氧化还原法,以及石墨烯/聚合物复合材料的制备方法(溶液共混、原位聚合和熔融共混)和性能(电学性能、导热性能、力学性能、热性能以及气体阻隔性能),并指出其待解决的关键技术及工业化前景。     

离子交换法合成MTX/LDHs复合物的研究及体外细胞实验的探索

研究了不同水热温度下合成的层状双金属氢氧化物(layered double hydroxides,LDHs)对离子交换法制备的MTX/LDHs纳米复合物的影响.并利用透射电镜(TEM)、X-射线衍射(XRD)、MTT等手段,对纳米复合物的结构及载药量、控释-缓释性、生物细胞活性母体等性质进行了系统研究.结果表明,不同LDHs母体对离子交换后复合物的形貌和性质起着至关重要的作用.在磷酸缓冲液中考察了MTX/LDHs纳米复合物的药物控释性能并进行了动力学拟合,结果表明,采用离子交换法制备MTX/LDHs纳米复合物的释药过程是Fick扩散控制的离子交换和粒内扩散过程.最后,采用MTT法探究了MTX/LDHs纳米复合物对肺癌细胞A549增殖的抑制作用,结果表明,复合物较纯的MTX具有更好的抑制癌细胞增殖的作用.     

Improving Thermal and Flame Retardant Properties of Epoxy Resin with Organic NiFe‐Layered Double Hydroxide‐Carbon Nanotubes Hybrids

To improve the dispersion of carbon nanotubes (CNTs) and flame retardancy of layered double hydroxide (LDH) in epoxy resin (EP), organic nickel‐iron layered double hydroxide (ONiFe‐LDH‐CNTs) hybrids were assembled through co‐precipitation. These hybrids were further used as reinforcing filler in EP. EP/ONiFe‐LDH‐CNTs nanocomposites containing 4 wt% of ONiFe‐LDH‐CNTs with different ratios of ONiFe‐LDH and CNTs were prepared by ultrasonic dispersion and program temperature curing. The structure and morphology of the obtained hybrids were characterized by different techniques. The dispersion of nanofillers in the EP matrix was observed by transmission electron microscopy (TEM). The results revealed a coexistence of exfoliated and intercalated ONiFe‐LDH‐ CNTs in polymer matrix. Strong combination of the above nanofillers with the EP matrix provided an efficient thermal and flame retardant improvement for the nanocomposites. It showed that EP/ONiFe‐LDH‐CNTs nanocomposites exhibited superior flame retardant and thermal properties compared with EP. Such improved thermal properties could be attributed to the better homogeneous dispersion, stronger interfacial interaction, excellent charring performance of ONiFe‐LDH and synergistic effect between ONiFe‐LDH and CNTs.     

Effect of nanosized carbon black on thermal stability and flame retardancy of polypropylene/carbon nanotubes nanocomposites

Nanosized carbon black (CB) was introduced into polypropylene/carbon nanotubes (PP/CNTs) nanocomposites to investigate the effect of multi‐component nanofillers on the thermal stability and flammability properties of PP. The obtained ternary nanocomposites displayed dramatically improved thermal stability compared with neat PP and PP/CNTs nanocomposites. Moreover, the flame retardancy of resultant nanocomposites was greatly improved with a significant reduction in peak heat release rate and increase of limited oxygen index value, and it was strongly dependent on the content of CB. This enhanced effect was attributed mainly to the formation of good carbon protective layers by CB and CNTs during combustion. Rheological properties further confirmed that CB played an important role on promoting the formation of crosslink network on the base of PP/CNTs system, which were also responsible for the improved thermal stability and flame retardancy of PP. Copyright © 2013 John Wiley & Sons, Ltd.     

Synthesis of functionalized α-zirconium phosphate modified with intumescent flame retardant and its application in poly(lactic acid)

A novel functionalized α-zirconium phosphate (F-ZrP) modified with intumescent flame retardant was synthesized by co-precipitation method and characterized. Poly (lactic acid) (PLA)/F-ZrP nanocomposites were prepared by melt blending method. The thermal stability and combustion behavior of PLA/F-ZrP nanocomposites were investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), vertical burning test (UL-94), scanning electronic microscopy (SEM), and cone calorimeter test (CCT). The results showed that the addition of flame retardant F-ZrP slightly affect PLA's thermal stability, but significantly improve the flame retardancy of PLA composites. In comparison with neat PLA, the LOI value of PLA/F-ZrP was increased from 19.0 to 26.5, and the UL-94 rating was enhanced to V-0 as the loading of F-ZrP at 10%. SEM results suggested the introduction of F-ZrP in the PLA system can form compact intumescent char layer during burning. All these results showed that the F-ZrP performed good flame retardancy for PLA.     

聚合物/层状硅酸盐纳米复合材料的性能

取合物／层状硅酸盐纳米复合材料是近十年发展起来的一类新型材料，即使硅酸盐纳米填料的含量很低，一般在5％（wt）以下，就使该类材料具有许多优良的性能，如杨氏模量，储能模量，热稳定性，气体阻隔性及阻燃性等均有较大的提高。本文综述了该类材料的性能。     

A novel intumescent flame retardant: Synthesis and application in ABS copolymer

A novel phosphorous-nitrogen structure containing intumescent flame retardant, poly(4,4-diaminodiphenyl methane spirocyclic pentaerythritol bisphosphonate) (PDSPB) was synthesized and characterized. Thermal stability and flammability properties of ABS/PDSPB composites were investigated by thermogravimetric analysis (TGA) and cone calorimeter test, respectively. The results showed that the addition of PDSPB enhanced the thermal stability and flame retardancy of ABS significantly. The weight of residues improved greatly with the addition of PDSPB. FTIR and SEM investigations revealed that the residual chars contain polyphosphoric or phosphoric acid, which plays an important role in the process of carbonization. The intumescent chars formed from PDSPB and ABS/PDSPB composites were intact, multicellular and strong. It is confirmed that the char structure was a critical factor for flame retardancy of ABS resin.     

The Role of Organomodified Different LDHs on Recycled Poly(ethylene terephthalate) Nanocomposites

Recycled poly(ethylene terephthalate)/organomodified‐layered double hydroxide (PET /organo‐LDH ) nanocomposites were successfully synthesized via a melt‐extrusion method. In an attempt to improve the compatibility with PET , LiAl , MgAl , and ZnAl LDH surfaces were modified with sulfanilic acid (SAS ) via electrostatic interaction with LDH cationic layers. In PET nanocomposites containing SAS ‐modified LDH , the (00l ) X‐ray diffraction (XRD ) peaks originating from organo‐LDH were not observed, indicating that the organomodified LDH layers were fully exfoliated and homogeneously dispersed within the PET matrix, which was also confirmed by transmission electron microscopy analysis. However, PET nanocomposites containing SAS ‐modified LiAl , MgAl , and ZnAl LDH showed broad (00l ) XRD peaks, indicating that the organo‐LDH was partially exfoliated. Thermogravimetric analysis confirmed that the thermal stability of PET/SAS‐modified LDH was significantly improved, depending on the type and loading content of SAS‐modified LDH compared to that of pristine PET . PET nanocomposites containing well‐dispersed SAS‐modified LDH showed substantial enhancement of the storage modulus.     

LDPE/Mg-Al layered double hydroxide nanocomposite: Thermal and flammability properties

Layered double hydroxides (LDHs) are new nanofillers which exhibit improved thermal and flammability properties in various kinds of polymer matrices. These materials have certain advantages over conventional metal hydroxides and also layered silicates so far as the flame retardancy is concerned. In this article, flammability and thermal properties of the nanocomposite based on low density polyethylene (LDPE) and Mg-Al based layered double hydroxide (Mg-Al LDH) are reported in detail. The nanocomposites containing different LDH concentrations were prepared by melt-compounding using a tightly intermeshing co-rotating twin-screw extruder. The morphological analysis reveals an exfoliated/intercalated type LDH particle morphology in these nanocomposites. The thermogravimetric analysis (TGA) shows that even a small amount of LDH improves the thermal stability and onset decomposition temperature in comparison with the unfilled LDPE. The heat release rate (HRR) and its maximum (PHRR) during cone-calorimeter investigation are found to be reduced significantly with increasing LDH concentration. The nanocomposites not only exhibit reduced total heat released (measure of propensity to produce long duration fire), but also lower tendency to fast fire growth (measured by the ratio of PHRR and time of ignition). The limited oxygen index (LOI) and the dripping behavior are also improved with increasing LDH concentration.