Influence of nucleating agent on the crystallization kinetics and morphology of polypropylene

Simanke, Adriane G.; Azeredo, Ana Paula de; Lemos, Cristóvão de; Mauler, Raquel Santos

doi:10.1590/0104-1428.2053

Cited by 22 publications

(14 citation statements)

References 15 publications

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“…The samples containing the nucleating agent showed a distinct peak; DMDBS 101.7 °C, SMBP 101.5 °C, and talc 95.9 °C. The influence of the addition of nucleating agent on temperature profiles has been investigated and similar results have been reported by several researchers . Sorbitol derivatives exhibit poor nucleation ability at low concentration …”

Section: Resultssupporting

confidence: 75%

“…Sorbitol derivatives, such as dibenzylidene sorbitol, 1,3:2,4‐di‐( p ‐methylbenzylidene)sorbitol, and DMDBS, are recognized nucleating agents and clarifiers. Several reports have revealed that the self‐organization mechanism of sorbitol molecules, in which intramolecular hydrogen bonding between hydroxyl groups affects the formation of nanofibrillar networks, leads to physical gels . In modest shear processes, the sorbitol fibrils are aligned in the direction of flow and nucleate polymer chains by epitaxial interaction.…”

Section: Introductionmentioning

confidence: 99%

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Enhancement of drawdown force in polypropylene containing nucleating agent

Phulkerd

Nakabayashi

Iwasaki

et al. 2018

J of Applied Polymer Sci

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The effect of the nucleation efficiency of three commercial nucleating agents, such as 1,3:2,4‐bis(3,4‐dimethylbenzylidene)sorbitol (DMDBS), sodium 2,2′‐methylene‐bis‐(4,6‐di‐tert‐butylphenyl)phosphate (SMBP), and magnesium silicate (talc), on the melt‐stretching performance of isotactic polypropylene (PP) is studied. It is found that the addition of 0.5 wt % of a nucleating agent enhances the crystallization temperature and that effect is pronounced for DMDBS and SMBP. Furthermore, DMDBS is more efficient than the other tested nucleating agents in enhancing the drawdown force, defined as a force required for stretching a molten strand. Nanofibers of DMDBS, which show significant alignment in the flow direction, are responsible for the rapid crystallization of PP in the flow field leading to an increase of drawdown force. The stretched strand shows a highly oriented structure in which the α‐form crystals orient to the flow direction. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47295.

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Section: Resultssupporting

confidence: 75%

Section: Introductionmentioning

confidence: 99%

Enhancement of drawdown force in polypropylene containing nucleating agent

Phulkerd

Nakabayashi

Iwasaki

et al. 2018

J of Applied Polymer Sci

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“…On the other hand, crystallization rate of PLA increased and the time to reach the 50% relative crystallinity decreased at higher cooling rates in the presence of green microalgae. Regarding higher crystallization half time (t 1/2 ) in the presence of green microalgae at the cooling rate of 1 • C/min might be attributed to the some degree of agglomeration of green microalgae in PLA matrix [22]. On the other hand, the t 1/2 value of PLA decreased in the presence of green microalgae for the other cooling rates, which showed that green microalgae enhanced the crystallization rate of PLA.…”

Section: Non-isothermal Crystallization Kineticsmentioning

confidence: 93%

Non-Isothermal Crystallization Kinetics of Green Microalgae Filled Poly(Lactic Acid)

et al. 2019

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In this study, the effect of green microalgae as a nucleating agent on the non-isothermal crystallization of poly(lactic acid) (PLA) was investigated by differential scanning calorimeter and polarized optical microscope. The parameters of non-isothermal crystallization kinetics of PLA and PLA/green microalgae composites were obtained through common kinetic models such as Avrami, Ozawa, and combined Avrami and Ozawa. Moreover, nucleating activity of green microalgae and activation energies of composites were determined by the Dobreva-Gutzow and the Friedman methods, respectively. Dispersion of green microalgae in PLA was characterized using scanning electron microscopy. PLA/green microalgae composites having different green microalgae content from 5 to 20 wt% were prepared via solvent casting method. Although some agglomerated green microalgae was observed in the PLA matrix, it was found that the green microalgae were homogeneously distributed within the matrix at its lower loading levels. The Avrami and combined Avrami-Ozawa results showed that PLA/green microalgae composites have faster melt crystallization rates than that of pure PLA. Nucleating activity of green microalgae was proved by the Dobreva and Gutzow kinetic approach. Moreover, polarized optical microscope analysis revealed that crystallization onset temperature of PLA shifted to higher temperature upon cooling in the presence of green microalgae.

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“…As the content of SP increased, the endothermic temperature increased only slightly, and the heat of fusion increased up to 3 wt% SP and then decreased, indicating that the crystallinity of pure PP slightly increased up to 3 wt% SP, whereas the crystalline size of pure PP decreased when SP was introduced. [44][45][46] However, at a high SP content of 5 wt%, the heat of fusion decreased.…”

Section: Thermal Propertiesmentioning

confidence: 99%

Preparation and characterization of polypropylene/sodium propionate (PP/SP) composite films for bread packaging application

2018

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To prolong the shelf life of bread, polypropylene/sodium propionate (PP/SP) composite films were prepared via a melt‐extrusion process. To investigate the feasibility of using PP/SP composite films as a bread packaging material, their chemical structure, morphology, mechanical properties, barrier properties against water, surface properties, and antimicrobial properties were investigated. A storage test for bread was also conducted. The mechanical and thermal stability of the PP/SP composite films enhanced with increasing SP content. Compared with pure PP, the PP/SP composites had increased hydrophilicity that increased with increasing SP content. These composite films showed enhanced antimicrobial activity against both Gram‐negative and Gram‐positive microorganisms. This was due to the interaction of SP and water originating from the bread, which modifies the pH of the bread and causes destruction of the cellular structures of fungi and also reduces the growth rate of bacteria. The enhanced thermal, mechanical, antifungal, and antimicrobial properties achieved by the addition of SP can be beneficial for maintaining the freshness of bread and prolonging its shelf life.

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Influence of nucleating agent on the crystallization kinetics and morphology of polypropylene

Cited by 22 publications

References 15 publications

Enhancement of drawdown force in polypropylene containing nucleating agent

Enhancement of drawdown force in polypropylene containing nucleating agent

Non-Isothermal Crystallization Kinetics of Green Microalgae Filled Poly(Lactic Acid)

Preparation and characterization of polypropylene/sodium propionate (PP/SP) composite films for bread packaging application

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