PVC/粘土纳米复合材料的研究进展

概述了PVC/粘土纳米复合材料的研究及发展现状，总结了离子交换、偶联剂处理、接枝改性等粘土的表面处理方法及直接熔融插层、原位插层聚合、共混等PVC/粘土纳米复合材料的制备方法，并分析了PVC/粘土纳米复合材料的性能及其发展前景。     

改性纳米CaCO3/PVC复合材料的力学性能

采用钛酸酯偶联剂和PMMA接枝方法改性纳米碳酸钙，并采用熔融共混法制备了改性纳米CaCO3增韧PVC（CaCO3／PVC）复合材料，研究了复合材料的力学性能。对比于未处理纳米CaCO，和钛酸酯偶联剂处理纳米CaCO3，PMMA接枝聚合改性纳米CaCO3与基体的相容性最好，增韧PVC复合材料的拉伸强度得到较大幅度提高。     

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。     

酰胺类改性剂对nano-CaCO_3的表面改性及其在PVC中的应用

为了改善纳米碳酸钙在聚氯乙烯(PVC)基体中的分散性和相容性,分别采用十八胺、十二胺和辛胺与马来酸酐反应,制备出三种改性剂;然后分别用这三种改性剂对纳米碳酸钙进行湿法改性,制备了PVC/纳米碳酸钙复合材料,系统研究了改性纳米碳酸钙对PVC复合材料力学性能的影响。结果表明:三种改性剂均可以与纳米碳酸钙表面结合,阻止了纳米碳酸钙的团聚,改性后的粒子可以均匀地分散在PVC基体中;三种改性剂改性的纳米碳酸钙都可以显著提高PVC复合材料的缺口冲击强度,但其弯曲强度和拉伸强度变化不大。     

纳米ZnO/PVC复合材料的制备及其性能研究

以钛酸酯偶联剂HY-201对纳米ZnO进行改性,通过双辊混炼法制备了改性纳米ZnO/PVC复合材料。研究了纳米改性复合材料的冲击强度、拉伸强度、维卡软化温度、邵氏硬度的变化规律。结果表明,随改性纳米ZnO份数的增加,复合材料的冲击强度、拉伸强度呈先上升后下降的趋势,而维卡软化温度以及邵氏硬度呈现上升后逐渐平稳的的趋势。     

聚氯乙烯树脂耐热和增韧改性研究进展

综述了聚氯乙烯（PVC）树脂耐热改性和增韧改性的研究进展。PVC耐热改性方法主要有添加热稳定剂、交联、共混、共聚、氯化及无机纳米粒子改性;增韧改性的主要方法包括弹性体、纳米粒子、聚合物/无机纳米复合材料、纳米级微纤增韧以及原位聚合的方法。最后,提出了PVC耐热和增韧改性的发展方向。     

纳米CaCO_3表面改性及其对PVC复合材料性能的影响

分别采用十八胺、十二胺和正辛胺对纳米CaCO3进行湿法改性,制备了聚氯乙烯(PVC)/纳米CaCO3复合材料,系统研究了不同改性剂改性的纳米CaCO3对PVC基复合材料力学性能的影响。结果表明:3种改性剂均可以与纳米CaCO3表面结合,形成一有机层,阻止了纳米CaCO3团聚,使改性后的粒子可以均匀分散在PVC基体中;十八胺、十二胺和正辛胺改性后的纳米CaCO3均可显著提高PVC复合材料的缺口冲击强度,并且随着改性剂分子链长度的增加,冲击强度也略有提高;改性纳米CaCO3可以略微提高复合材料的弯曲强度,但材料的拉伸强度略有下降。     

聚合物包覆对纳米CaCO3在PVC中分散的影响

以偶联改性纳米CaCO3和甲基丙烯酸甲酯（MMA）为原料,原位乳液聚合制得PMMA接枝包覆纳米CaCO3,以其与PVC熔融共混制备复合材料,研究了纳米CaCO3在共混体中的分散和与PVC界面的结合.与未改性纳米CaCO3相比,纳米CaCO3接枝包覆PMMA后,在PVC中的分散性能得到明显改善,粒子被分散得更加细小、均匀.PMMA接枝包覆纳米CaCO3与PVC界面间相容性能最好,比小分子改性CaCO3与PVC间的黏结作用更强.采用PMMA包覆纳米CaCO3粒子改性PVC,比未改性纳米CaCO3改性PVC有更好的冲击性能及拉伸性能.     

纳米CaCO_3的接枝改性及其填充PVC复合材料的性能

采用表面原位接枝聚合在纳米CaCO3颗粒表面引入聚甲基丙烯酸甲酯(PMMA)或聚丙烯酸丁酯(PBA),用共混法制备了纳米CaC03/PVC复合材料,研究了不同界面特性时纳米CaCO,/PVC复合材料的力学性能.研究结果表明:通过表面原位接枝聚合反应可以在纳米CaCO3颗粒表面接枝PMMA和PBA;表面接枝聚合改性大大促进了纳米CaCO3粒子在PVC基体中的分散行为,增加了复合材料的拉伸强度以及与聚合物的界面粘接强度,但复合材料的冲击强度有所下降.     

PEO处理蒙脱土填充PVC的制备与力学性能

为更加有效地制备聚氯乙烯和蒙脱土纳米复合材料及增加两者之间的相容性，将聚氧化乙烯(PEO)和钠基蒙脱土(MMT)在水中复合，制得凝胶，此凝胶干燥粉碎用于填充聚氯乙烯(PVC)，研究了对复合材料力学性能的影响。结果表明，PEO能够提高MMT对PVC的相容性，PVC／P-MMT复合材料具有较好的力学性能。因此，PEO和MMT的复合不失为制备有机改性纳米蒙脱土的有效方法。     

Preparation and Electron Beam Irradiation of PVC/ENR/CNTs Nanocomposites

Poly (vinyl chloride), PVC/epoxidized natural rubber blend, ENR/carbon nanotubes, CNTs nanocomposites were prepared using melt intercalation and solution blending methods. In both preparation methods PVC: ENR: CNTs ratios were fixed at 50:50:2, while the 50/50 PVC/ENR blend without the addition of CNTs was used as control. The PVC/ENR/CNTs nanocomposites were exposed to electron beam (EB) irradiation at doses ranging from 0–200 kGy. The effects of two different preparation methods on the tensile properties, gel fraction and morphology of the PVC/ENR/CNTs nanocomposites were studied. Prior to EB irradiation, the addition of 2 phr of CNTs caused a drop in the tensile strength (Ts) of the 50/50 PVC/ENR blend, implying poor distribution of CNTs in the PVC/ENR blend matrix. However upon EB irradiation, the nanocomposites prepared by the melt blending method exhibited higher values of Ts as compared to the neat PVC/ENR blend due to occurrence of radiation-induced cross-linking in the PVC/ENR blend matrix. Transmission electron microscopy (TEM) images proved that a better dispersion of CNTs in PVC/ENR blend matrix can be achieved by melt intercalation compared to solution blending and the dispersion of CNTs was improved by irradiation. Scanning electron microscopy (SEM) results showed a distinct failure surface with formation of rough structure for the irradiated nanocomposites, which explains the higher values of tensile properties compared to the non-irradiated nanocomposites.     

Thermal stability and flame retardance properties of acrylonitrile-butadiene-styrene/polyvinyl chloride/organophilic Fe-montmorillonite nanocomposites

In the article, acrylonitrile-butadiene-styrene/polyvinyl chloride/organophilic Fe-montmorillonite (ABS/PVC/Fe-OMT) nanocomposites were prepared by melt intercalation method. In order to determine if the presence of iron ion in the structure of organophilic montmorillonite (OMT) lattice can affect thermal, flame retardance and smoke suppressant properties in the ABS/PVC blends. ABS/PVC/organophilic natural montmorillonite (Na-OMT) nanocomposites were prepared as the comparable sample. Fe-MMT and Na-MMT were treated by cetyl trimethylammonium bromide (CTAB). The information on morphologies and structures of ABS/PVC/OMT nanocomposites was obtained using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The thermal properties of the nanocomposites were characterized by thermogravimetric analysis, and flame retardant properties were obtained via limiting oxygen index (LOI), UL-94 vertical burning test and smoke density. The nanocomposites, based on Fe-OMT, exhibited better flame retardance, better smoke suppressant properties, and lower degradation degree than those of pure ABS/PVC blends and the ABS/PVC/Na-OMT nanocomposites.     

Epoxidized Mesua ferrea L. seed oil‐plasticized thermostable PVC and PVC‐clay nanocomposites

The use of vegetable‐oil‐based polymeric plasticizers with nanotechnology can create new applications for plasticized poly(vinyl chloride) (PVC). Epoxidized Mesua ferrea L. (Ceylon Ironwood) seed oil was used as a plasticizer for PVC. Further, nanocomposites were prepared through an ex‐situ technique using epoxidized‐oil‐swelled organically modified montmorillonite (5 wt%) and PVC. Notable improvement in thermal and processing characteristics of the nanocomposites was observed over those of the virgin polymer (in both unplasticized and plasticized PVC), as studied by TGA. The prepared nanocomposites were characterized by FTIR, SEM, TEM, and XRD techniques. A dramatic decrease in viscosity (7‐fold) was observed in THF for a 10% solution of epoxidized‐oil‐modified PVC compared to unplasticized PVC in THF, as measured by Brookfield viscometer. Isothermal analysis at three different temperatures (100, 150, and 200°C) reveals sufficient stability of the epoxidized oil modified PVC nanocomposites, as confirmed by gravimetric and FTIR analysis. Augmentation of thermostability and good retention of mechanical properties of the (Mesua ferrea L.)‐plasticized‐PVC/clay nanocomposites with respect to rigid PVC vouch for the utility of the former as advanced industrial materials. J. VINYL ADDIT. TECHNOL., 18:168–177, 2012. © 2012 Society of Plastics Engineers     

Morphology and properties of PVC/clay nanocomposites via in situ emulsion polymerization

PVC/Na⁺–montmorillonite (MMT) nanocomposites were prepared via a simple technique of emulsion polymerization at several different MMT clay concentrations. X‐ray diffraction and transmission electron microscopy studies revealed the formation of a mixture of intercalated and exfoliated nanostructure. Tensile testing results showed that the tensile modulus of the nanocomposites increased with the addition of clay, while the tensile strength decreased little. The notched impact strength of the nanocomposites was also improved. For systems containing clay in the range of 2.1 to 3.5 wt %, the impact strength was almost two times as large as that of pure PVC. However, those mechanical properties began to decrease with the continuously increasing amount of clay. The fracture surface of pure PVC and the nanocomposites was observed by scanning electron microscope. Thermal properties of the nanocomposites were found to increase as a result of clay incorporation. The glass transition temperatures of the PVC/clay nanocomposites were nearly identical to that of pure PVC. The Vicat softening points exhibited a progressively increasing trend with the clay content added. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 277–286, 2004     

Influence of graphite nanosheets on the structure and properties of PVC‐based nanocomposites

Polyvinyl chloride‐ (PVC)‐ based nanocomposites, containing graphite nanosheets (G), which may be used as electromagnetic wave absorbers was developed and investigated. The microstructure of polyvinyl chloride/graphite nanocomposites (PVC/G) were examined by means of X ‐ray diffraction, scanning electron microscopy (SEM), and thermal gravimetric analyses (TGA). SEM image reveals that the graphite nanosheets were well dispersed in the PVC matrix without agglomeration. Thermal stability of the PVC/G nanocomposites is improved as a result of inclusion of graphite nanosheets. The PVC/G nanocomposites were characterized to investigate the effect of dispersion of graphite nanosheets in PVC matrix. The dielectric spectroscopy of PVC/G nanocomposites in frequency range from 1 to 12 GHz has been performed. The results show that PVC/G nanocomposites exhibit high dielectric constant at the measured frequencies. Coefficient of attenuation and coefficient of reflection of PVC/G composites have been also examined in a frequency range from 1 to 12 GHz. The electromagnetic interference shielding effectiveness (EMI) depends on graphite volume fraction in the composite. The results show that the PVC/G represents a new class of conducting lightweight nanomaterial that can absorb electromagnetic waves at microwave frequency and may be promising for future commercial use. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

NBR/PVC/OMMT纳米复合材料的结构与性能研究

采用乳液共沉法和直接混炼法制备NBR/PVC/有机蒙脱土（OMMT）纳米复合材料,研究纳米复合材料的硫化特性、微观结构、动态力学性能和热稳定性.结果表明,OMMT能够显著促进NBR的硫化反应,使NBR/PVC/OMMT纳米复合材料的焦烧时间和正硫化时间明显缩短;乳液共沉法和直接混炼法NBR/PVC/OMMT纳米复合材料是插层型纳米复合材料,乳液共沉法NBR/PVC/OMMT纳米复合材料中的OMMT分散更为均匀,其储能模量、玻璃化温度和热分解温度均高于NBR/PVC共混物和直接混炼法NBR/PVC/OMMT纳米复合材料,具有较好的动态力学性能和热稳定性.     

Enhancement of the thermal stability,mechanical properties and morphologies of recycled PVC/clay nanocomposites

Summary Recycled PVC/clay nanocomposites were prepared by melt mixing of recycled PVCs and modified clays. Characterization of the nanostructure of the nanocomposites was carried out using wide angle X-ray diffraction (WAXD) and transmission electron microscopy(TEM). In case of 10wt.%, the characteristic peak of modified clay was perfectly disappeared, because of aids of plasticizers as co-intercalator. Thermal stability was evaluated from the thermal decomposition behaviors and linear dimension changes by TGA and TMA system. Coefficients of thermal expansion of the nanocomposites were also observed from TMA analysis. Dynamic mechanical properties were evaluated using DMA system. The thermal and mechanical properties of the nanocomposites were improved simultaneously for varied clay loadings, 1,3,5,10wt.%, compared to recycled PVC. Especially, the storage modulus of the nanocomposites with 10wt.% clay loading was increased 11 times compared to that of recycled PVC.     

Thermal,thermomechanical, and morphological characterization of poly(vinyl chloride) (PVC)/ZnO nanocomposites: PVC molecular weight effect

Poly(vinyl chloride) (PVC)‐based nanocomposites containing 2 wt% zinc oxide (ZnO) nanoparticles were prepared by solution casting and the effect of the PVC molecular weight (MW) on the morphology, thermal properties, and thermogravimetric behavior was studied. The addition of ZnO nanoparticles to PVCs of different MWs increased the glass transition temperature (T_g) of the resulting nanocomposites, the extent of which was dependent upon the MW of the PVC matrix. The nanocomposite samples exhibited broadened transition zones as compared with their unfilled PVC matrices. The extent of transition zone broadening was also controlled by the MW of the PVC matrix in the nanocomposites. In the absence of ZnO nanoparticles, the increase in MW of PVC had no effect on the breadth of the transition zone. The TGA results showed that the incorporation of ZnO nanoparticles into PVC matrices of different MWs accelerated the first stage weight loss via the nanoparticle catalytic effect through removal of HCL from the polymeric chains. The presence of ZnO nanoparticles lowered the second stage weight loss, and the char yield obtained for nanocomposites samples was significantly greater than that obtained for neat PVC samples. At low MWs, the presence of ZnO nanoparticles had no effect on the first stage of thermal degradation process. The presence of ZnO nanoparticles in the matrix in different nanocomposites was revealed by SEM observations, and the EDX analysis demonstrated a progressive improvement in the distribution and dispersion state of ZnO nanoparticles in the PVC‐based nanocomposites as the MW of PVC matrix gradually increased. J. VINYL ADDIT. TECHNOL., 25:E63–E71, 2019. © 2018 Society of Plastics Engineers     

Effects of processing on the structure of PVC/montmorillonite composites. I. Melt and solution processes

The effects of processing conditions on the structure of poly(vinyl chloride) (PVC)/clay composites were investigated. Dry‐blending conditions were shown to affect composite structure in compression‐molded samples. PVC/(Cloisite Na) nanocomposites could not be prepared by melt compounding. Partially exfoliated and intercalated PVC/(Cloisite 30B) nanocomposites could be prepared by melt compounding. The effects of the grain structure of PVC resin and the PVC fusion mechanism on nanocomposite formation were considered. The particulate structure of the PVC resin was found to restrict the distribution ofclay, which could be improved by increasing the processing temperature. Almost fully exfoliated PVC/(Cloisite 30B) nanocomposites were prepared from solutions in tetrahydrofuran, and the plasticizer migration resistance of these composites was substantially improved. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers