The activity of inorganic substrates in the catalysed nucleation of different polymer melts

Rodrguez-Prez, M.A.; Vasiliev, Ts.; Dobreva-Veleva, A.; Saja, J.A. de; Gutzow, I.; Velasco, J. I.

doi:10.1002/1521-3900(200105)169:1<137::aid-masy137>3.0.co;2-q

Cited by 8 publications

(3 citation statements)

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“…Despite previous studies on conventional mineral‐filled polymers, where adding a filler resulted in higher glass transition temperature, the results presented here have shown that, in the case of PP/clay nanocomposites, the glass transition occurred at similar or lower temperatures than for the pure PP. The same result has also been observed in talc‐filled PP composites 27. Different effects would affect the glass transition of PP/clay nanocomposites.…”

Section: Resultssupporting

confidence: 78%

Polypropylene/clay nanocomposites: Combined effects of clay treatment and compatibilizer polymers on the structure and properties

Velasco

Raso

Realinho

et al. 2006

J of Applied Polymer Sci

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Combined effects of clay treatment and compatibilizer polymers on the structure and properties of polypropylene/clay nanocomposites were studied. Dynamic mechanical analysis was used to analyze comparatively the dynamic mechanical response of different nanocomposites prepared from polypropylene and montmorilloniterich bentonite, and to relate such response with the material microstructure. Two different bentonites were used: a purified Spanish natural bentonite was organophillized by means of 11-undecyl-ammonium ion and a commercial bentonite organophillized with dimethyl dehydrogenated tallow ammonium ion. Three different polar copolymers were employed as compatibilizer agents in some of the formulations: maleic anhydride-grafted polypropylene, maleic anhydride-grafted poly(styrene-co-ethylenebutyleneco-styrene), and poly(ethylene terephthalate-co-isophthalate) (PET). To ascertain the microstructure characteristics in the nanocomposites, wide angle X-ray diffraction, transmission electron microscopy, and differential scanning calorimetry techniques were used. The nanocomposites containing both bentonite organophillized with 11-undecylammonium ion and PET, and maleated PP as compatibilizer system, were found to have the highest storage modulus and the smallest loss factor values, which was mainly due to the better clay platelets dispersion. The dynamic mechanical response of nanocomposites prepared with bentonite organophillized with dimethyl dehydrogenated tallow ammonium ion and maleated SEBS was strongly affected by the presence of this compatibilizer. The temperature of PP and a, b, and g relaxations strongly depended on the interactions between the different phases in the nanocomposites.

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Section: Resultssupporting

confidence: 78%

Polypropylene/clay nanocomposites: Combined effects of clay treatment and compatibilizer polymers on the structure and properties

Velasco

Raso

Realinho

et al. 2006

J of Applied Polymer Sci

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“…The lower the ratio drops below 1, the higher the nucleation activity is. The lnβ vs. ∆T −2 p plots are sometimes found to be nonlinear, which complicates this type of analysis [104,105]. An example of such plots for the crystallization of polyethylene terephthalate (PET) is displayed in Figure 9.…”

Section: Turnbull-fisher Treatment For Broad Temperature Rangementioning

confidence: 99%

“…An example of such plots for the crystallization of polyethylene terephthalate (PET) is displayed in Figure 9. To overcome this issue, only the slower (≤10 K/min) cooling rates had to be used [104]. The applicability of this approach for estimating the nucleation activity in a broad range of cooling rates seems generally questionable because of the nonlinearity of lnβ vs. ∆T −2 p plots [104,105].…”

Section: Turnbull-fisher Treatment For Broad Temperature Rangementioning

confidence: 99%

Nonisothermal Crystallization Kinetics by DSC: Practical Overview

Vyazovkin

Sbirrazzuoli

2023

Processes

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Providing a minimum of theory, this review focuses on practical aspects of analyzing the kinetics of nonisothermal crystallization as measured with differential scanning calorimetry (DSC). It is noted that kinetic analysis is dominated by approaches based on the Avrami and Arrhenius equations. Crystallization kinetics should not be considered synonymous with the Avrami model, whose nonisothermal applications are subject to very restrictive assumptions. The Arrhenius equation can serve only as a narrow temperature range approximation of the actual bell-shaped temperature dependence of the crystallization rate. Tests of the applicability of both equations are discussed. Most traditional kinetic methods tend to offer very unsophisticated treatments, limited only to either glass or melt crystallization. Differential or flexible integral isoconversional methods are applicable to both glass and melt crystallization because they can accurately approximate the temperature dependence of the crystallization rate with a series of the Arrhenius equations, each of which corresponds to its own narrow temperature interval. The resulting temperature dependence of the isoconversional activation energy can be parameterized in terms of the Turnbull–Fisher or Hoffman–Lauritzen theories, and the parameters obtained can be meaningfully interpreted and used for kinetic simulations.

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Nucleation Efficiency Measures

2016

Handbook of Nucleating Agents

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The activity of inorganic substrates in the catalysed nucleation of different polymer melts

Cited by 8 publications

References 0 publications

Polypropylene/clay nanocomposites: Combined effects of clay treatment and compatibilizer polymers on the structure and properties

Polypropylene/clay nanocomposites: Combined effects of clay treatment and compatibilizer polymers on the structure and properties

Nonisothermal Crystallization Kinetics by DSC: Practical Overview

Nucleation Efficiency Measures

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