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Polypropylene

About: Polypropylene is a research topic. Over the lifetime, 32310 publications have been published within this topic receiving 336463 citations. The topic is also known as: polypropene & PP.


Papers
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Journal ArticleDOI
TL;DR: An overview of polymer-clay hybrid nanocomposites is provided with emphasis placed on the use of alkylammonium exchanged smectite clays as the reinforcement phase in selected polymer matrices as discussed by the authors.

2,403 citations

Patent
22 Feb 1972
TL;DR: In this article, an improved melt-blowing process is proposed in which thermoplastic polymer resins, preferably polypropylene, having initial intrinsic viscosities of at least 1.4, are degraded, optionally in the presence of a free radical source compound, to have both reduced intrinsic viscoities and an apparent viscoity in the meltblowing nozzle orifices of from about 50 to about 300 poise.
Abstract: Melt blown non-woven mats prepared from thermoplastic polymer fibers and substantially completely free of polymer shot are produced at high polymer throughput rates in an improved melt blowing process in which thermoplastic polymer resins, preferably polypropylene, having initial intrinsic viscosities of at least 1.4, are degraded, optionally in the presence of a free radical source compound, to have both reduced intrinsic viscosities and an apparent viscosity in the melt-blowing nozzle orifices of from about 50 to about 300 poise.

1,521 citations

Journal ArticleDOI
TL;DR: The synthetic routes and materials properties of polypropylene/montmorillonite nanocomposites are reviewed in this article, where the resulting polymer/inorganic structures are characterized by a coexistence of intercalated and exfoliated montmorillonites layers.
Abstract: The synthetic routes and materials properties of polypropylene/montmorillonite nanocomposites are reviewed. The nanocomposite formation is achieved in two ways: either by using functionalized polypropylenes and common organo-montmorillonites, or by using neat/unmodified polypropylene and a semi-fluorinated organic modification for the silicates. All the hybrids can be formed by solventless melt-intercalation or extrusion, and the resulting polymer/inorganic structures are characterized by a coexistence of intercalated and exfoliated montmorillonite layers. Small additionstypically less than 6 wt %of these nanoscale inorganic fillers promote concurrently several of the polypropylene materials properties, including improved tensile characteristics, higher heat deflection temperature, retained optical clarity, high barrier properties, better scratch resistance, and increased flame retardancy.

871 citations

Journal ArticleDOI
TL;DR: In this article, the physicochemical properties of polypropylene-maleic anhydride copolymer copolymers were characterized by contact angle measurements, and the chemical structure was identified with ESCA and FTIR.
Abstract: Cellulose fibers were surface modified with polypropylene–maleic anhydride copolymer. The physical properties of such fibers were characterized by contact angle measurements, and the chemical structure was identified with ESCA and FTIR. ESCA showed that the modifying agent was localized at the surface of the fibers. The modified fibers were compounded with polypropylene, and composites with various amount of fibers were manufactured by injection molding. All mechanical properties were improved when treated fibers were used. SEM showed improved dispersion, wetting of fibers, and adhesion. The nature of adhesion was studied using FTIR. It was found that the surface modifying agent is covalently bonded to the fibers through esterification. The degree of esterification is enhanced by activating the modifying agent before fiber treatment. This study has shown the effects of treatment conditions on activation of reactive species and chemical reaction between fiber and modifying agent. Moreover, a better understanding has been achieved of the nature of adhesion for the system.

762 citations

Journal ArticleDOI
TL;DR: In this paper, a linear crystalline polymers of α-olefins are synthesized and the properties of polypropylene, poly-α-butylene, and polystyrene are discussed.
Abstract: Publisher Summary This chapter discusses crystalline high polymers of α-olefins. The linear crystalline polymers of α-olefins are synthesized and the chapter also discusses the properties of crystalline polypropylene, poly-α-butylene, and polystyrene. Depending on the structure of the catalyst, different amounts, ranging from 0 to 100%, of the polymerization products are crystallizable and can be separated easily from the much more soluble noncrystalline polymers by solvent extraction. The new crystalline poly hydrocarbons have higher melting point, higher density, and lower solubility in organic solvents than the corresponding amorphous polyhydrocarbons having intrinsic viscosity of the same order of magnitude. The infrared spectra of crystalline polypropylene, of melted samples of the same polymer and of the amorphous polypropylene, show between 2 and 7.5 μ, the high adsorption regions characteristic of hydrocarbons.

728 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,359
20222,604
2021633
2020882
20191,551
20181,821