纳米粒子在聚合物共混物中选择性分布研究进展

介绍了纳米粒子在聚合物共混物中选择性分布的影响因素和控制方法;重点介绍了炭黑(CB)、碳纳米管(CNTs)、二氧化硅(SiO_2)、蒙脱土(MMT)、石墨烯等纳米粒子在共混物中的选择性分布现象;阐述了各种纳米粒子的选择性分布对聚合物共混物的相形态结构、流变性能、电性能和宏观力学性能等的影响。     

纳米无机粒子在聚合物合金中的选择性分布与迁移机理

概括了决定纳米无机粒子在聚合物共混物中选择性分布的有关因素,强调了聚合物对纳米无机粒子的浸润这一热力学因素和与共混过程有关的动力学因素的影响,并综述了纳米无机粒子迁移的3种可能的机理。     

聚合物共混物增容剂的研究

相容性聚合物共混物由于其优异的性能已成为新材料的主要研究方向。但许多共混物是互不相容的,因此必须改善它们的相容性。综述了聚合物共混物的相容性及各类增容剂的特点及应用。同时介绍了无机纳米粒子的引入对不相容聚合物共混体系相容性的影响。     

聚合物共混物及纳米粒子选择性分布研究进展

随着世界经济的进步与发展,社会对材料性能的要求也越来越高,复合材料已经逐渐取代单一聚合物材料。自20世纪60年代以来,纳米材料因其优异的性能,得到广泛人们关注,使得纳米复合材料成为了科学研究的新宠。然而,在不相容共混物中,纳米粒子的加入会存在选选择性分布的问题。本文综述了国内外聚合物纳米复合材料以及以及纳米粒子选择性分布研究,并对其发展趋势进行了展望。     

无机粒子对聚合物共混物相容性及相结构的影响

综述了无机粒子的引入对部分相容聚合物共混体系相行为和相结构演变的影响,同时介绍了无机粒子的引入对不相容聚合物共混体系热力学相容性和相结构演变(包括分散相的尺寸和形状、相转变及共连续结构的稳定性)的影响,并指出了今后研究中需要解决的一些问题。     

聚合物熔体超声挤出技术研究综述

综述了超声对聚合物挤出加工性能、化学反应、聚合物共混物相形态、结晶性聚合物的结晶行为、聚合物共混物力学性能等的影响。提出超声挤出技术实现工业化需解决的问题,展望了超声挤出技术在聚合物熔体反应挤出中的研究及应用前景。     

含废丁腈硫化胶粉的NBR／SAN热塑性弹性体共混物的热流变性能

深入了解聚合物共混物和合金的流变性能，对控制聚合物的形态和优化加工条件是很重要的。聚合物共混在熔化状态通常会生成两个或两个以上的相，这可能是由不同聚合物的低混合熵引起的一种现象。研究人员刘具有不同相对分子质量分布的高密度聚乙烯（HDPE）共混物和聚苯乙烯／聚丙烯共混物的流变性能进行了试验性研究。     

共混聚合物界面相容性研究进展

综述了改善共混物界面相容性的3种方法。提高大多数不相容聚合物相容性的方法主要是加入嵌段或接枝共聚物等增容剂;对其中一相进行化学改性的方法在生物高分子领域有较多的应用;由于无机纳米粒子有增强增韧的作用且较容易获得,因此,加入无机纳米粒子改善共混聚合物相容性的方法具有很大的发展空间。     

PC／PET共混条件及共混物组成对形态及性能的影响

本文探讨了PC/PET熔融共混体系混炼条件对性能的影响,得到了研究范围内最佳混炼条件,深入研究了该条件下共混物的力学性能、耐溶剂性和热性能,得到了性能优良的聚合物合金。与断面形态相结合讨论了共混物的性能与共混物中两相连续程度的对应关系。     

超临界CO_2制备聚合物及其共混物的应用现状

综述了超临界CO2制备聚合物及其共混物的应用现状,主要包括超临界CO2降低单一聚合物和聚合物共混物的黏度、改变聚合物共混物相行为及其他性能的应用。超临界CO2降低聚合物熔体黏度可以使聚合物的成型温度降低,提高其加工性。在聚合物共混物中引入超临界CO2,能改变聚合物共混物微观相形态,分散相尺寸减小,进而达到改变其他性能的目的。     

Uneven distribution of nanoparticles in immiscible fluids: Morphology development in polymer blends

The present review aims at summarizing the current knowledge on how solid nanoparticles organize in polymer blends. First, the behavior of low viscosity fluid emulsions containing solid colloidal particles is briefly presented. By contrast with polymer blends, they have been the subject of intensive studies for a long time, with both applicative and comprehensive objectives. High viscosity fluid emulsions like polymer blends loaded with nanofillers have received less attention until the recent enthusiasm about nanotechnology and more specifically polymer nanocomposites. Some similarities and differences between both types of emulsions are highlighted. The solid particles are well known to distribute unevenly in those types of complex fluids and the factors that determine their distribution in polymer blends are discussed. A particular emphasis is given on the competition between thermodynamic wetting of the solid by the polymeric phases and kinetic control of the filler localization directly linked to the rate of the mixing process. This aspect is believed to be a specificity of filled polymer blends and is known to have a drastic and sometimes predominant effect on particle localization. It explains that finely tuned morphologies can be obtained where the particles do not occupy their equilibrium position.     

Rheology and morphology of polymer blends containing liquid-crystalline component in melt and solid state

The rheological properties of polymer blends containing polysulfone and LC polyester have been investigated in terms of the morphology and physical-mechanical characteristics of the extrudates. The peculiarities of rheological behavior are connected with the morphology of stream, the latter being maintained also in solid extrudates. The reinforcement of an isotropic matrix by LC polymers as well as formation of an anisotropic surface layer leads to a specific change in the strength properties of compositions. A maximal increase in the strength and initial modulus was observed for blends containing not more than 10% LC polymer.     

Manipulating the phase morphology in PPS/PA66 blends using clay

By adding a small amount of clay into poly(p‐phenylene sulfide) (PPS)/polyamide 66 blends, the morphology was found to change gradually from sea–island into cocontinuity and lamellar supramolecular structure, as increasing of clay content. Clay was selectively located in the PA66 phase, and the exfoliated clay layers formed an edge‐contacted network. The change of morphology is not caused by the change of volume ratio and viscosity ratio but can be well explained by the dynamic interplay of phase separation between PPS and PA66 through preferential adsorption of PA66 onto the clay layers and through layer–layer repulsion. This provides a means of manipulating the phase morphology for the immiscible polymer blends. The mechanical and tribological properties of PPS/PA66 blends with different phase morphologies (different clay contents) were studied. Both tensile and impact strength of the blends were found obviously increased by the addition of clay. The antiwear property was greatly improved for the blends with cocontinuous phase form. Our work indicates that the phase‐separating behavior of polymer blends contained interacting clay can be exploited to create a rich diversity of new structures and useful nanocomposites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Preparation of polypropylene and polystyrene with NCO and NH2 functional groups and their applications in polypropylene/polystyrene blends

Isocyanate‐ and amine‐functionalized polypropylene (PP) and polystyrene (PS) were prepared through grafting and copolymerization method. These compounds are used as precursors for PP‐graft‐PS (PP‐g‐PS) copolymers and reacted at the matrix interface of PP/PS blends. Functionalized polymer structures were characterized by ¹H NMR and FTIR spectroscopy. The effects of the synthesized compatibilizer on the rheological and morphological behavior of PP/PS blends were investigated systematically. Results showed that the functional polymer was successfully synthesized, and the additional two different compatibilizer systems dramatically decreased the size of the dispersed phase domains in PP/PS blends. Compared with the uncompatibilized blends, compatibilized blends exhibited a slightly higher crystallization temperature because the melting points of the blend components were not evidently affected by the addition of compatibilizer, as revealed by differential scanning calorimetry. The compatibilizer effect on the PP/PS blends was reflected through rheological property and dynamic mechanical analysis. POLYM. ENG. SCI., 55:614–623, 2015. © 2014 Society of Plastics Engineers     

Polymer blends with a crystallizable diblock copolymer: Thermal properties and phase behavior

We report on the thermal behavior of polymer blends comprising a block copolymer and random copolymers of styrene and acrylonitrile (SAN). The block copolymer constituents are ε-caprolactone (CL) and a carbonate. Melting as well as crystallization behavior of the blocks are strongly influenced by addition of amorphous SAN, which is miscible only with PCL block. Blends under discussion can undergo different phase changes as macro- and microphase separation and crystallization. Hence, morphology formation is controlled by different transitions and even a cooperative interplay between them. Phase behavior of the blends is discussed and correlated with results of morphological studies.     

Solution and solid‐state NMR investigation of poly(methyl methacrylate)/poly(vinyl pyrrolidone) blends

The development of polymer blends has become very important for the polymer industry because these blends have shown to be a successful and versatile alternative way to obtain a new polymer. In this study, binary blends formed by poly(methyl methacrylate) (PMMA) and poly(vinyl pyrrolidone) were prepared by solution casting and evaluated by solution and solid‐state NMR. Variations in the microstructure of PMMA were analyzed by ¹³C solution NMR. Solid‐state NMR promotes responses on physical interaction, homogeneity, and compatibility to use these blends to understand the behavior of the ternary blends. The NMR results led‐us to acquire information on the polymer blend microstructure and molecular dynamic behavior. From the NMR solution, it was possible to evaluate the microstructure of both polymer blend components; they were atactic. From the solid state, good compatibility between both polymer components was characterized. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 372–377, 2004     

Polymer blends and alloys—a review of selected considerations

A brief overview of the important issues governing the behavior of polymer blends is presented. Thermodynamic issues which determine the phase behavior of blends are reviewed and qualitatively related to physical interactions between blend components. The influence of melt processing conditions on the resulting properties and behavior of both miscible and immiscible blends is reviewed. The physical properties of blends are reviewed and illustrated by examples from recent work on miscible blends of polycarbonate with a copolyester and on the immiscible blends of polystyrene with high density polyethylene.     

Effects of blend composition on the morphologies and physical properties of polycarbonate/acrylonitrile-butadiene-styrene blends

The morphologies and physical properties of twin-screw-extruded polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends with various blend ratios are studied. The needle-like co-continuous phase in PC-rich blends changes to the sea-island phase for blend ratios of more than 50 wt% ABS. While pure PC exhibits an almost-Newtonian flow behavior, PC/ABS blends exhibit the interesting rheological transition. The viscosities of the ABS-rich blends at low shear rates are almost equal to those of the pure ABS polymer. The yield stress for the PC/ABS blend ratio of 3:7 is the highest in composition. At the frequency of 10 rad/s, the PC-rich blends exhibit highly viscous properties, whereas the ABS-rich blends present highly elastic properties as the temperature increases. Moreover, the ABS polymer in the PC/ABS polymer blend induces significant change at the fracture surface of PC, transitioning from brittle to ductile nature.     

Thermodynamic miscibility of polymer-liquid crystal blends

The thermodynamic phase behavior of two polymer-liquid crystal blends was investigated in both the solid and molten states. One of the blends (p-hexyloxybenzoic acid and poly[ethylene glycol]) contains a semi-crystalline polymer. The second example (p-pentyloxycinnamic acid and bisphenol-A polycarbonate) contains a high-impact-resistant amorphous thermoplastic. Whereas, the former system is almost completely immiscible at ambient temperature, yet advantageous for applications in the microelectronics industry, the latter blend exhibits partial (concentration-dependent) miscibility. Our multi-technique assessment of miscibility/phase separation includes high-resolution carbon-13 solid state NMR spectroscopy, differential scanning calorimetry (DSC), and group-contribution thermodynamics (Universal Quasi-Chemical Functional-Group Activity Coefficient formalism including a Free Volume correction for the small molecule activity, UNIFAC-FV). Approximate temperature-composition (equilibrium) phase diagrams are constructed for both blends in light of the results from NMR, DSC, and UNIFAC-FV.     

PET/PEN共混体系的相容性和热性能研究

主要研究了 PET/PEN共混体系的相容性和热性能 ,发现 PET和 PEN具有较好的相容性 ,体系的耐热性和耐热水解性随 PEN量的增加而得到明显改善