聚氯乙烯纳米复合材料研究进展

阐述了共混法、原位聚合法和插层聚合法等聚氯乙烯(PVC)纳米复合材料的制备方法,介绍了PVC/无机粒子、PVC/黏土等几种纳米复合材料的性能,指出了PVC纳米复合材料的发展方向。     

聚丙烯/黏土纳米复合材料结构及流变性能研究

采用固相法对黏土进行插层改性,制备有机黏土,再与聚丙烯熔融共混,成功制备聚丙烯/有机黏土纳米复合材料。XRD和TEM测试均表明:固相法改性黏土可以与聚丙烯形成结构为插层型和剥离型共存的纳米复合材料。利用动态流变仪研究纳米复合材料的加工流变性能,结果显示,有机黏土的加入有效地改善了聚丙烯的加工流变性能。     

聚氯乙烯纳米复合材料研究进展

介绍了近年来聚氯乙烯(PVC)纳米复合材料的制备方法及PVC纳米复合材料的研究现状和应用。目前,应用于PVC改性的纳米材料主要有无机纳米粒子、层状的黏土等,制备方法除了采用常用的共混法及插层法外,还有原位聚合法等。研究发现,通过纳米改性的PVC在力学、光学、电学性能等方面有较大的提高。     

固相法改性粘土及其在聚氯乙烯中的应用

首先采用固相法对粘土进行有机化插层改性,制得有机粘土,再通过熔融插层法制备聚氯乙烯/有机粘土复合材料。XRD表明固相法改性粘土可以与聚氯乙烯形成纳米复合材料。利用DSC研究了纳米复合材料的玻璃化转变温度,结果显示:聚氯乙烯/有机粘土纳米复合材料的玻璃化转变温度高于纯聚氯乙烯。     

硫化方法对橡胶/黏土纳米复合材料黏土片层分散状态的影响

通过熔体插层法以及常压硫化法制备了橡胶/黏土纳米复合材料,并与模压硫化法制备的复合材料进行了对比,研究了硫化方法对橡胶/黏土纳米复合材料微观分散状态的影响。结果表明:采用熔体插层法制备的橡胶/黏土混合物,其受限状态的橡胶大分子链在高温、高压条件下,在黏土片层之间处于一种热力学不稳定状态;模压处理会对橡胶/黏土混合物的分散状态产生不利影响。透射电子显微镜和X光衍射分析表明,采用模压硫化、常压硫化得到的丁基橡胶或丁苯橡胶/黏土纳米复合材料中黏土片层的微观分散状态不同;排除压力的影响,常压硫化有利于提高橡胶/黏土纳米复合材料中黏土片层的分散程度。     

固相法制备有机黏土改性聚丙烯

采用固相法对黏土进行有机化插层改性,制备出有机黏土;通过熔融插层法制备聚丙烯/有机黏土纳米复合材料。X射线衍射分析表明,固相法改性黏土可以与聚丙烯形成纳米复合材料。利用DSC研究了纳米复合材料的结晶和熔融过程,结果表明:聚丙烯/有机黏土纳米复合材料的结晶温度提高,熔融过程、熔点及结晶度没有明显变化。力学性能测试结果表明:有机黏土含量在3%～5%范围内,纳米复合材料的力学性能最佳。     

固相法插层改性黏土在PP中的应用

采用固相法对黏土进行有机化插层改性制备有机黏土,再通过熔融插层法制备聚丙烯(PP)/有机黏土纳米复合材料。有机黏土在PP中的层间距由原来的4.07 nm扩大到5.84 nm,PP分子链成功插入到固相法改性的黏土中,形成纳米复合材料。PP/有机黏土纳米复合材料的结晶温度由112.9℃提高119.6℃,熔融过程、熔点及结晶度没有明显变化。PP/有机黏土纳米复合材料的力学性能优于PP/钠基黏土复合材料,有机黏土的质量分数在3%-5%时,纳米复合材料的力学性能最佳。     

季鏻盐改性黏土及其对尼龙6性能的影响

首先采用季鏻盐作为插层剂对钠基黏土进行插层改性,制备有机黏土,再与尼龙6熔融共混,成功制备尼龙6/有机黏土纳米复合材料。XRD测试结果表明:季鏻盐改性黏土可以与尼龙6形成纳米复合材料。转矩流变仪的测试结果显示:有机黏土能够略微改善尼龙6树脂的加工性能。力学性能的测试结果显示:有机黏土的含量在3%~5%范围内其,纳米复合材料的力学性能最佳。     

有机改性与乳液插层法相结合制备的丁苯橡胶/黏纳米复合材料的结构与性能(英文)

针对现有的乳液插层法所制备的橡胶/黏土纳米复合材料中填料与橡胶之间界面结合较弱的缺点,在乳液插层法中对无机黏土进行有机改性,制备出力学性能优异的纳米复合材料。X射线衍射和透射电子显微镜技术分析表明,有机改性后的复合材料中黏土被部分地有机改性,且在基体中以纳米尺寸分散。     

聚合物/纳米黏土复合材料的研究进展

简述了纳米黏土的结构特点,常见的有机化改性方法,介绍了可插层黏土的有机单体和聚合物类型。综述了聚合物/纳米黏土复合材料的制备方法,介绍了单体溶液插层、聚合物水溶液插层、乳液插层等溶液插层方法和单体熔融插层、聚合物熔融插层、熔融挤出插层等熔融插层方法。总结了聚合物/纳米黏土复合材料的国内外研究进展与应用现状,主要在汽车工业、包装材料、环境友好材料、新型工程材料等领域得到了广泛应用。     

聚乙烯醇／蒙脱土复合材料的结构与性能研究

采用熔融插层法制备了聚乙烯醇(PVA)／蒙脱土(MMT)复合材料。通过X射线衍射仪和透射电镜对复合材料的结构进行表征，结果表明所得复合材料为剥离型或部分剥离型结构。热重测试、电子拉力试验和水溶性试验结果显示聚乙烯醇／蒙脱土纳米复合材料与纯聚乙烯醇相比，其加工热稳定性、综合力学性能以及耐水性能都得到了明显提高。     

聚氯乙烯／蒙脱土复合材料的结构与性能研究

采用熔融共混法制备得到PVC／蒙脱土复合材料。通过X射线衍射和透射电镜对复合材料的结构进行了表征。研究了钠基蒙脱土和烷基季铵盐改性的有机蒙脱土对聚氯乙烯／蒙脱土复合材料的结构、加工热稳定性、光学性能、力学性能和结构流变性能的影响。     

蒙脱土对聚合物颜色及力学性能的影响

通过熔融共混法制备了聚丙烯／蒙脱土(MMT)、(苯乙烯／丁二烯／苯乙烯)共聚物／MMT及聚氯乙烯／MMT共混物。研究了MMT在聚合物加工过程中,以及在热老化过程中对聚合物耐老化性能的影响。在不同混炼时间及热老化时间下,共混物的黄度指数相对纯聚合物有明显提高。力学性能的测试结果也表明,MMT对聚合物的老化有一定促进作用。     

Properties of Poly(vinyl chloride)/poly(ethylene oxide)/polyaniline Conductive Films: The Effect of Poly(ethylene glycol) Diglycidyl Ether

The effect of polyaniline and poly(ethylene glycol) diglycidyl ether on tensile properties, morphology, thermal degradation, and electrical conductivity of poly(vinyl chloride)/poly(ethylene oxide)/polyaniline conductive films was studied. The poly(vinyl chloride)/poly(ethylene oxide)/polyaniline conductive films were prepared using a solution casting technique at room temperature until a homogeneous solution was produced. Poly(vinyl chloride)/poly(ethylene oxide)/polyaniline/poly(ethylene glycol) diglycidyl ether conductive films exhibit higher electrical properties, tensile strength, modulus of elasticity but lower final decomposition temperature than poly(vinyl chloride)/poly(ethylene oxide)/polyaniline conductive films. Scanning electron microscopy morphology showed that the polyaniline more widely dispersed in the poly(vinyl chloride)/poly(ethylene oxide) blends with the addition of poly(ethylene glycol) diglycidyl ether as surface modifier.     

Mechanical properties,flame retardancy,and smoke suppression of lanthanum organic montmorillonite/poly(vinyl chloride) nanocomposites

A dimethyl dioctadecyl ammonium chloride modified organic montmorillonite (OMMT_‐I.44P)/poly(vinyl chloride) (PVC) nanocomposite and anionic‐surfactant‐modified lanthanum organic montmorillonite (La‐OMMT)/PVC nanocomposites (with three different anionic surfactants for the La‐OMMTs) were prepared via melt‐intercalation technology. The effects of the La‐OMMTs and OMMT_‐I.44P on the mechanical properties, flame retardancy, and smoke suppression of PVC were studied. X‐ray diffraction characterization showed that the La‐OMMTs were exfoliated in the PVC matrix. The mechanical properties of the nanocomposites were enhanced by the incorporation of the La‐OMMTs. Cone calorimetry and gas chromatography–mass spectrometry analyses indicated that the incorporation of the La‐OMMTs enhanced the flame retardancy and smoke suppression of the PVC nanocomposites. Scanning electron microscopy photos further showed that the residual char surfaces of La‐OMMT/PVC were all intact and, thus, provided better barriers to energy and smoke transport. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43951.     

有机蒙脱土对PVC复合材料热降解性能的影响

采用热重分析研究了有机蒙脱土(OMMT)用量对聚氯乙烯(PVS)复合材料热降解过程的影响,并采用Flynn-wall-Ozawa方法分析计算得到了复合材料体系的表观活化能.研究表明,在PVC材料降解初期(转化率小于30%),OMMT的加入使得PVC降解活化能都有不同程度的下降;但随着降解过程的继续,PVC的降解活化能又开始逐渐增大.     

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.     

Thermal aging and accelerated weathering of PVC/MMT nanocomposites: Structural and morphological studies

This work focuses on the influence of weathering factors—UV radiation, humidity, and temperature on the structure and morphology of poly(vinyl chloride)/montmorillonite (PVC/MMT) nanocomposites obtained by melt blending. It has been observed that organically modified MMT (OMMT) deteriorates the weathering resistance, the thermal behavior, as well as the long‐term stability of PVC. Decomposition of the organic modifier of MMT causes substantial color changes in the PVC nanocomposites as it facilitates the dehydrochlorination process of the polymer. However, the nonmodified MMT provides some stabilization during PVC weathering. The nanocomposites after annealing are characterized by higher glass transition temperature. The increase in heat capacity step (Δc_p) during glass transition suggests that in the PVC composites with nonmodified MMT stronger molecular interactions between the polymer and clay platelets occur than in PVC/OMMT nanocomposites. The scanning electron microscopy images on the surface and the cross section show that thermal aging and weathering proceed by different mechanisms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42090.     

Investigation of the thermal,mechanical and morphological properties of poly(vinyl chloride)/polyhedral oligomeric silsesquioxane nanocomposites

Research into organic–inorganic nanocomposites has recently become popular, particularly the development of new polymer nanocomposites. Compared to pristine polymers or conventional composites, these nanocomposites exhibit improved properties. The storage modulus of a poly(vinyl chloride) (PVC)/polyhedral oligomeric silsesquioxane (POSS) nanocomposite slightly decreased with POSS content, but had a higher modulus from 50 to 100 °C. Some of the material appeared to be aggregated with 1 wt% POSS in the polymeric matrix. Conversely, with a POSS content of 5 wt%, a better dispersion of the nanoparticles was observed. The presence of POSS in the plasticised PVC compound had little influence on the final properties of the nanocomposites, showing weaker interactions between the POSS and the plasticised PVC compound. Copyright © 2010 Society of Chemical Industry     

Synergetic effect of dimerized pentaerythritol esters with synergetic metal soap on the stabilization of poly(vinyl chloride)

The synergetic effect of dimerized pentaerythritol esters, as novel costabilizer, with metal soap, the mixture of zinc and calcium stearates, as stabilizer, on the undesirable discoloration of poly(vinyl chloride) (PVC) by heating was investigated. The dimerized pentaerythritol esters were prepared by the esterification of pentaerythritol using stearic acid and the dimerization of the obtained pentaerythritol ester using unsaturated dicarboxylic acid. This dimer was used to improve its poor compatibility with PVC. The degree of esterification for pentaerythritol was varied from half to the full amount of hydroxyl groups. Both stabilizer and costabilizer were compounded into poly(vinyl chloride) through roll mixing. As a result, the dimerized pentaerythritol esters showed good dispersibility in poly(vinyl chloride). The effect of suppressing the discoloration was obtained in the systems used, not only the half‐esterified type but also the full‐esterified type, although it had no hydroxyl group. The abrupt discoloration was caused by the formation of a π complex between cool color producing metal chloride, i.e., zinc chloride from the metal soap and double bonds from the dehydrochlorination in poly(vinyl chloride) chain. Usually, the hydroxyl group containing compounds are said to be useful for suppressing the discoloration because the hydroxyl group captures the metal chloride. In the costabilizing effect of the full esterified type, it was clarified from the X‐ray photoelectron spectroscopic analysis and infrared spectrum observations for the model mixtures, that the decomposition of the ester group could occur, and the excess zinc chloride was captured as colorless zinc carboxylate. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2029–2037, 2001