Nonisothermal crystallization behavior and molecular dynamics of poly(lactic acid) plasticized with jojoba oil

Saad, Gamal R.; Elsawy, Moataz A.; Aziz, Mohamed S. Abdel

doi:10.1007/s10973-016-5910-z

Cited by 24 publications

(23 citation statements)

References 64 publications

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“…Double melting peaks were detected for all PLA samples. A similar trend was observed by other authors for PLA blends [35][36][37], and this phenomenon reflects the melting process of crystals with different degrees of perfection. Note that the value of the maximum melting peak did not change significantly (approximately ± 3°C) in response to increasing heating rate or the incorporation of PHO and talc (approximately ± 3°C).…”

Section: Thermal Gravimetric Analysis (Tga)supporting

confidence: 90%

“…This finding means that the neat PLA and its samples exhibit heterogeneous, threedimensional spherulitic growth. Similar results have also been reported by Li et al [2] and Saad et al [35]. The values of k c increased with increasing heating rate, and the k c values were smaller for pure PLA than for the rest of the samples.…”

Section: Nonisothermal Cold Crystallization Kineticssupporting

confidence: 90%

“…This model implies that during the process of transformation, the activation energy, E, should differ during the transformation. The Kissinger approach has been used in several recent studies [1,10,17,35,40]. The kinetic model equation combined with the Arrhenius method to the temperature function of the reaction rate constant can usually be defined as follows [43,44]: (6) where t is the time, T is the temperature, α is the relative degree of crystallinity, A (s -1 ) is the pre-exponential (frequency) factor, E (kJ mol -1 ) is the activation energy, R is the universal gas constant, and f(α) is the reaction model.…”

Section: Activation Energy Of Crystallizationmentioning

confidence: 99%

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Nonisothermal Cold Crystallization Kinetics of Poly(lactic acid)/Bacterial Poly(hydroxyoctanoate) (PHO)/Talc

2019

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The effects of bacterial poly(hydroxyoctanoate) (PHO) and talc on the nonisothermal cold crystallization behaviours of poly(lactic acid) (PLA) were analysed with differential scanning calorimetry (DSC), and the thermal stability of the samples was observed with thermal gravimetric analysis (TGA). The modified Avrami’s model was used to describe the nonisothermal cold crystallization kinetics of neat PLA and its blends. The activation energies E for nonisothermal cold crystallization were calculated by the isoconversional method of Kissinger-Akahira-Sunose (KAS). The DSC results showed that the PLA/PHO blends were immiscible in the whole studied range, and as the PHO and talc content increased, the crystallization rate of PLA accelerated, and the crystallinity of PLA in the PLA samples increased. The values of the Avrami exponent indicated that the nonisothermal cold crystallization of the neat PLA and its blends exhibited heterogeneous, three-dimensional spherulitic growth. The E values were strongly dependent on PHO and talc. The TGA results showed that the presence of PHO and talc slightly influenced the thermal stability of PLA.

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Section: Thermal Gravimetric Analysis (Tga)supporting

confidence: 90%

Section: Nonisothermal Cold Crystallization Kineticssupporting

confidence: 90%

Section: Activation Energy Of Crystallizationmentioning

confidence: 99%

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Nonisothermal Cold Crystallization Kinetics of Poly(lactic acid)/Bacterial Poly(hydroxyoctanoate) (PHO)/Talc

2019

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“…Plasticizers such as poly(ethylene glycol) and acetyl triethyl citrate combined with talc caused an increase in PLA's crystallinity [24]. Natural jojoba oil also increased crystallization rate of polylactide, but did not influence the kinetic energy of crystallization [25]. Properties of polylactide can also be changed by producing composites based on this material.…”

Section: Introductionmentioning

confidence: 99%

Crystallization of polylactide-based green composites filled with oil-rich waste fillers

Mysiukiewicz

Barczewski

2020

J Polym Res

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Polylactide is a highly demanded biopolymer, whose industrial application constantly increases. Its disadvantages such as brittleness and slow crystallization rate can be overcome by application of different additives. Because of environmental issues, using natural waste fillers as modifying agents for polylactide is especially interesting. In this study linseed cake, a byproduct of oil extraction from linseed, characterized by oil content of 0.9–39.8 wt.%, was added to polylactide to influence its crystallization behavior. The formation of the crystalline phase was studied by differential scanning calorimetry in isothermal and non-isothermal conditions and analyzed according to methods by Jeziorny, Ozawa, Mo and Avrami. The samples’ microstructures were observed using polarized light microscopy. The crystallization rate and Avrami exponent of samples crystallized in different conditions were evaluated. It was found that addition of 10 wt.% of linseed cake containing at least 17.7 wt.% oil notably changes the crystallization of polylactide, increasing its crystallinity and promoting the growth of crystallites.

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“…Thereby improving the crystallization rate of PLLA in the manufacturing process has important guiding significance for theoretical research and practical application. The introduction of a nucleating agent into PLLA have been proved to be a good and costeffective way for accelerating the crystallization process [10], resulting from that a nucleating agent can lower the surface free energy barrier to nucleation and initiate crystallization at a higher temperature zone in cooling [12]. Upon to now, a great deal of compounds with inorganic structures, organic structures, or macromolecular structures have been devoted to be as heterogenous nucleating agents for PLLA.…”

Section: Introduction mentioning

confidence: 99%

Heterogeneous Nucleation Effect of N, N'-Adipic Bis(4-phenylbutyric Acid) Dihydrazide on Crystallization Process of Poly(L-lactic Acid)

Cai¹,

Zhao²

2019

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Enhancing crystallization ability is a fundamental challenges in Poly(L-lactic acid) (PLLA) industry, therefore, the goal of this work was to synthesis a new organic nucleating agent N, N'-adipic bis(4-phenylbutyric acid) dihydrazide (APAD), and investigate its effect on non-isothermal crystallization, isothermal crystallization, melting behavior, thermal stability, and optical property of PLLA. Non-isothermal melt crystallization results showed that APAD acted as more effective nucleating and accelerating agent for the crystallization of PLLA, as a result, upon cooling at 1 °C/min, PLLA/0.5 %APAD had the highest onset crystallization temperature 136.4 °C and the crystallization peak temperature 132.0 °C, as well as the largest non-isothermal crystallization enthalpy 48.1 J/g. However, with increasing of APAD concentration from 0.5 wt.% to 3 wt.%, the crystallization peak shifted to the lower temperature. In contrast, for the non-isothermal cold crystallization process, the effect of APAD concentration on the crystallization behavior of PLLA was negligible. Additionally, the non-isothermal crystallization process was also depended on the cooling rates and the final melting temperature. In isothermal crystallization section, to compare with the primary PLLA, the crystallization half-time of PLLA/APAD could decrease from 254.3 s to the minimum value 29.4 s, with 0.5 wt.% APAD contents at 125 °C. Melting behavior of PLLA/APAD samples under different conditions further confirmed the heterogeneous nucleation effect of APAD for PLLA, and the appearance of the double melting peaks was attributed to the melting-recrystallization. Finally, the addition of APAD decreased the thermal stability to some extent, although APAD could not change the thermal decomposition profile of PLLA. And a drop of PLLA/APAD samples in light transmittance resulted from the double influence of the enhancement of crystallization and the opaqueness of APAD.

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Nonisothermal crystallization behavior and molecular dynamics of poly(lactic acid) plasticized with jojoba oil

Cited by 24 publications

References 64 publications

Nonisothermal Cold Crystallization Kinetics of Poly(lactic acid)/Bacterial Poly(hydroxyoctanoate) (PHO)/Talc

Nonisothermal Cold Crystallization Kinetics of Poly(lactic acid)/Bacterial Poly(hydroxyoctanoate) (PHO)/Talc

Crystallization of polylactide-based green composites filled with oil-rich waste fillers

Heterogeneous Nucleation Effect of N, N'-Adipic Bis(4-phenylbutyric Acid) Dihydrazide on Crystallization Process of Poly(L-lactic Acid)

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