Kinetics of non-isothermal crystallization of polyethylene and polypropylene

Eder, M.; Włochowicz, A.

doi:10.1016/0032-3861(83)90177-5

Cited by 161 publications

(91 citation statements)

References 8 publications

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“…PP gives a value in the range of 2.8-3.3, suggesting that the nucleated process leads to a spherulitic growth with thermal nucleation. 22 The values of m were larger for the PP nanocomposites which is consistent with PP crystalli- (a) zation at higher temperature 27,41 and crystallization with a nano-scale reinforcement. 27 This finding shows that the type of nucleation and the geometry of the crystal growth markedly change in the presence of graphite.…”

Section: Crystallization Kinetics Modellingsupporting

confidence: 68%

“…The crystallization temperatures are those corresponding to the exothermic peak maxima (T p ) as described by Elder and Wlochowicz. 41 The enthalpy of crystallization (ÁH c ) has been calculated from the enthalpy of crystallization normalized to the PP content, assuming that the thermodynamic contribution of the graphite phase is negligible. The percent crystallinity of pure PP and the PP matrix in the nanocomposites was determined by eq 1 where the value of the heat of crystallinity of pure crystalline PP (ÁH 0 c ) was assumed to be 146.5 J/g.…”

Section: Crystallization Behaviormentioning

confidence: 99%

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Properties and Crystallization of Maleated Polypropylene/Graphite Flake Nanocomposites

Pagé

Gopakumar

2006

Polym J

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ABSTRACT:Polypropylene (PP)/graphite (G) hybrid nanocomposites have been prepared by melt mixing using maleated PP (PP-g-MA) and graphite oxide (GO) as compatibilizing agents. Melt mixing was achieved using a Gelimat, a high-speed thermo-kinetic mixer. The PP-g-MA and GO used as compatibilizers helped the dispersion of the graphite on a nano-scale and improved flexural properties but more significantly the impact strength of the material. TEM micrographs showed a partial exfoliation of the graphite in the PP/PP-g-MA/GO/G hybrid nanocomposites. SEM micrographs of etched nanocomposite samples showed a fine grain micron-sized structure, while pure PP was characterized by larger 3-dimensional spherulites. Non-isothermal crystallization kinetics of PP and PP/PP-g-MA/ GO/G nanocomposites were investigated by differential scanning calorimetry (DSC). The crystallinity and crystallization temperature of the nanocomposites were higher than for neat PP. Using the Kissinger model, the activation energy of crystallization of the nanocomposites was determined to be lower than PP. Models by Ozawa and Liu et al. were used to analyze and describe the non-isothermal crystallization kinetics. Overall, results indicate that the type of nucleation, growth and geometry of PP crystals markedly change in the presence of nano-sized graphite particles.

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Section: Crystallization Kinetics Modellingsupporting

confidence: 68%

Section: Crystallization Behaviormentioning

confidence: 99%

Properties and Crystallization of Maleated Polypropylene/Graphite Flake Nanocomposites

Pagé

Gopakumar

2006

Polym J

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“…The experimental facts indicate that the Ozawa equation is not suitable for describing the kinetics in the non-isothermal crystallization process of sPS and its composites. This result may arise due to the secondary crystallization and the dependence of the fold length on temperature for sPS, as well as instantaneous nucleation, rapid impingement and possibly secondary crystallization for the nanocomposites [55][56][57].…”

Section: Non-isothermal Crystallization Behaviormentioning

confidence: 99%

Non-isothermal crystallization kinetics of syndiotactic polystyrene polystyrene functionalized SWNTs nanocomposites

Xiong

Gao²,

Li³

2007

Express Polym. Lett.

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Carbon nanotubes (CNTs) are unique nanostructured materials with remarkable physical, mechanical and electronic properties [1][2][3][4]. These properties make them attractive for applications in many scientific and technological fields such as electronic structures [5], polymer composites [6], and biological systems [7]. Among these potential applications, the prospect of obtaining high-performance CNT based polymeric nanocomposites has attracted the efforts of researchers in both academia and industry [8]. The combination of organic polymer components with CNT fillers in a single material has extraordinary significance for the development of advanced materials with remarkable mechanical, electrical, thermal and multifunctional properties [9][10][11][12]. Moreover, polymer/CNT nanocomposites challenge traditional filled polymers (loadings of 20 wt% or more) in many of these areas by providing similar physical enhancements but with as little as about 1 wt% addition of dispersed nanotubes [13]. Previous CNT based polymeric nanocomposites reports include increased modulus, impact strength, heat distortion temperature, and barrier properties with decreased thermal expansivity [14][15][16]. In addition, these nanocomposites are finding potential applications such as electrostatically dissipative materials and aerospace materials [17]. Currently, several processing methods, including melt mixing, solution process and in-situ polymerization [18][19][20] Abstract. Non-isothermal crystallization kinetics were characterized by using differential scanning calorimetry (DSC) analysis on neat semicrystalline syndiotactic polystyrene (sPS) and its nanocomposites with polystyrene (PS) functionalized full-length single walled carbon nanotubes (SWNT-PS), which was prepared by copper (I) catalyzed click coupling of alkyne-decorated SWNTs with well-defined, azide-terminated PS. The crystallization behavior of neat sPS polymer was compared to its SWNT based nanocomposites. The results suggested that the non-isothermal crystallization behavior of sPS/SWNT-PS nanocomposites depended significantly on the SWNT-PS contents and cooling rate. The incorporation of SWNT-PS caused a change in the mechanism of nucleation and the crystal growth of sPS crystallites, this effect being more significant at lower SWNT-PS content. Combined Avrami and Ozawa analysis was found to be effective in describing the non-isothermal crystallization of the neat sPS and its nanocomposites. The activation energy of sPS determined from nonisothermal data decreased with the presence of small quantity of SWNT-PS in the nanocomposites and then increased with increasing SWNT-PS contents.

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“…14, [23][24][25] m is determined by the conversion ratio X(T) and time T by plotting ln[ − ln(1 − X(T))] against ln| β | as follows:…”

Section: Mo Modelmentioning

confidence: 99%

Crystallization Kinetics of 2CaO·Fe2O3 and CaO·Fe2O3 in the CaO–Fe2O3 System

Ding

Chen

et al. 2016

ISIJ International

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Kinetics of non-isothermal crystallization of polyethylene and polypropylene

Cited by 161 publications

References 8 publications

Properties and Crystallization of Maleated Polypropylene/Graphite Flake Nanocomposites

Properties and Crystallization of Maleated Polypropylene/Graphite Flake Nanocomposites

Non-isothermal crystallization kinetics of syndiotactic polystyrene polystyrene functionalized SWNTs nanocomposites

Crystallization Kinetics of 2CaO·Fe<sub>2</sub>O<sub>3</sub> and CaO·Fe<sub>2</sub>O<sub>3</sub> in the CaO–Fe<sub>2</sub>O<sub>3</sub> System

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