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Polymer blend

About: Polymer blend is a research topic. Over the lifetime, 18474 publications have been published within this topic receiving 437183 citations. The topic is also known as: polymer mixture & Polymerblend 或者 Polyblend.


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Patent
08 Feb 1979
TL;DR: In this article, the authors define an excellent seal packaging material, which comprises a base layer consisting of a stretched film made of a polymer composition comprising a propylene polymer, and a surface layer made of polymeric mixture comprising a polymer blend provided on at least one surface of the base layer.
Abstract: A packaging material having an excellent seal packaging property, which comprises (A) a base layer consisting of a stretched film made of a polymer composition comprising a propylene polymer and (B) a surface layer consisting of a stretched film made of a polymeric mixture comprising a polymer blend provided on at least one surface of said base layer, said polymer blend comprising a copolymer of ethylene and propylene and a copolymer of butene and any other polymerizable monomer having an ethylenic unsaturation in a weight proportion of 5:95 to 95:5.

141 citations

Journal ArticleDOI
TL;DR: In this article, the role of interfacially located nanoparticles on the coalescence in immiscible blends is investigated systematically to clarify their role as compared to that of block copolymers.
Abstract: Blending of two or more immiscible polymers is an attractive route to generate new materials. However, during processing in the liquid state, the flow-induced microstructure changes continuously due to a complex interplay between break-up and coalescence, typically resulting in a coarse morphology with poor properties. Hence, the need to generate and stabilize a fine morphology is obvious and block copolymers are typically used as compatibilizers. The use of nanoparticles has been suggested to be an alternative to ‘compatibilize’ immiscible polymer pairs. In the present work, the role of interfacially located nanoparticles on the coalescence in immiscible blends is investigated systematically to clarify their role as compared to that of block copolymers. A (70/30 vol%) polydimethylsiloxane (PDMS)/polyisobutylene (PIB) blend with a droplet/matrix microstructure is chosen as a model system. Contact angle measurements and theoretical models are used to select the surface chemistry of the nanoparticles to ensure their localization at the polymer/polymer interface, which is experimentally verified by scanning microscopy under cryogenic conditions. Using a rheological method it is shown that coalescence of the dispersed phase is slowed down or even totally suppressed when nanoparticles are present at the interface. This effect becomes stronger when the particle concentration is increased or the (aggregate) size is reduced. Additionally, anisotropic nanoparticles tend to stabilize blends more efficiently than their spherical counterparts. A combination of optical microscopy and interfacial rheometry using planar interfaces has been used to demonstrate that the nanoparticles mainly affect the surface rheological properties, whereas traditional compatibilizers also strongly affect the interfacial tension. As a result, nanoparticles with a suitable surface chemistry can be used to tune the flow-induced microstructure of immiscible polymer blends by optimizing their concentration, size and shape.

140 citations

Journal ArticleDOI
TL;DR: In this paper, a molecular nano-floating gate (NFG) of pentacene-based transistor memory devices is developed using conjugated polymer nanoparticles (CPN) as the discrete trapping sites embedded in an insulating polymer, poly (methacrylic acid) (PMAA).
Abstract: A molecular nano-floating gate (NFG) of pentacene-based transistor memory devices is developed using conjugated polymer nanoparticles (CPN) as the discrete trapping sites embedded in an insulating polymer, poly (methacrylic acid) (PMAA). The nanoparticles of polyfluorene (PF) and poly(fluorene-alt-benzo[2,1,3]thiadiazole (PFBT) with average diameters of around 50–70 nm are used as charge-trapping sites, while hydrophilic PMAA serves as a matrix and a tunneling layer. By inserting PF nanoparticles as the floating gate, the transistor memory device reveals a controllable threshold voltage shift, indicating effectively electron-trapping by the PF CPN. The electron-storage capability can be further improved using the PFBT-based NFG since their lower unoccupied molecular orbital level is beneficial for stabilization of the trapped charges, leading a large memory window (35 V), retention time longer than 104 s with a high ON/OFF ratio of >104. In addition, the memory device performance using conjugated polymer nanoparticle NFG is much higher than that of the corresponding polymer blend thin films of PF/polystyrene. It suggests that the discrete polymer nanoparticles can be effectively covered by the tunneling layer, PMAA, to achieve the superior memory characteristics.

140 citations

Journal ArticleDOI
TL;DR: In this article, composites containing either carbon black (CB), graphite (G), or carbon fiber (CF) were used to produce ternary composites with a synergistic effect on electrical conductivity.
Abstract: Conductive polymer composites possessing a low percolation-threshold concentration as a result of double percolation of a conductive filler and its host phase in an immiscible polymer blend afford a desirable alternative to conventional composites. In this work, blends of high-density polyethylene (HDPE) and ultrahigh molecular weight polyethylene (UHMWPE) were used to produce ternary composites containing either carbon black (CB), graphite (G), or carbon fiber (CF). Blend composition had a synergistic effect on electrical conductivity, with pronounced conductivity maxima observed at about 70–80 wt % UHMWPE in the CB and G composites. A much broader maximum occurred at about 25 wt % UHMWPE in composites prepared with CF. Optical and electron microscopies were used to ascertain the extent to which the polymers, and hence filler particles, are segregated. Differential scanning calorimetry of the composites confirmed that the constituent polymers are indistinguishable in terms of their thermal signatures and virtually unaffected by the presence of any of the fillers examined here. Dynamic mechanical analysis revealed that CF imparts the greatest stiffness and thermal stability to the composites. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1013–1023, 2002

140 citations

Journal ArticleDOI
TL;DR: The photophysical properties of a solution processed blend of two semiconducting polymers with electron donating and electron accepting properties, respectively, as used in polymer photovoltaic devices have been investigated in this paper.
Abstract: The photophysical properties of a solution processed blend of two semiconducting polymers with electron donating and electron accepting properties, respectively, as used in polymer photovoltaic devices have been investigated. We show that in the binary mixture of poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and poly[oxa-1,4-phenylene-(1-cyano-1,2-vinylene)-(2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylene)-1,2-(2-cyanovinylene)-1,4-phenylene] (PCNEPV) photoexcitation of either one of the polymers results in formation of a luminescent exciplex at the interface of the two materials. Photoinduced absorption spectroscopy shows that this exciplex can decay to the lowest triplet state $({T}_{1})$ of MDMO-PPV. Application of an electric field results in dissociation of the marginally stable exciplex into charge carriers, which provides the basis for the photovoltaic effect of this combination of materials. Spin allowed recombination of the charge carriers to the MDMO-PPV ${T}_{1}$ state is invoked to explain the field-enhanced quantum yield for triplet formation observed by photoinduced reflection measurements on photovoltaic devices made from the composite films. The field enhanced triplet yield is identified as loss mechanism for the photovoltaic performance of this combination of materials.

140 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202383
2022167
2021411
2020451
2019427
2018439