Non-isothermal crystallization behaviors and spherulitic morphology of poly(lactic acid) nucleated by a novel nucleating agent

Poly(lactic acid) (PLA)/graphene nanocomposites were prepared by solution blending using chloroform as a mutual solvent. Transmission electron microscopy (TEM) was used to examine the quality of the dispersion of graphene in the PLA matrix. The isothermal crystallization behaviors of PLA and PLA/graphene nanocomposites were investigated by differential scanning calorimetry (DSC). The isothermal crystallization kinetics were analyzed by Avrami model based on the DSC data. The results showed that the well dispersed graphene nanosheets could act as a heterogeneous nucleating agent and lead to an acceleration of crystallization during the PLA isothermal crystallization process. According to the Arrhenius equation, the activation energies were found to be -106.9 and -46.6 kJ/mol for pure PLA and PLA/0.1 wt % graphene nanocomposite, respectively. The crystal morphology were characterized with polarizing optical microscope (POM).

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Non-isothermal crystallization kinetics of poly (lactic acid)/graphene nanocomposites

Journal of Polymer Engineering ◽

10.1515/polyeng-2012-0124 ◽

2013 ◽

Vol 33 (2) ◽

pp. 163-171 ◽

Cited By ~ 11

Author(s):

Yanhua Chen ◽

Xiayin Yao ◽

Qun Gu ◽

Zhijuan Pan

Keyword(s):

Lactic Acid ◽

Isothermal Crystallization ◽

Crystallization Rate ◽

Nucleating Agent ◽

Poly Lactic Acid ◽

Scanning Calorimetry ◽

Graphene Nanocomposites ◽

Solution Blending ◽

Transmission Electron ◽

Graphene Nanocomposite

Abstract Poly(lactic acid) (PLA)/graphene nanocomposites were prepared by solution blending and the dispersibility of graphene in the PLA matrix was examined by transmission electron microscopy (TEM). The non-isothermal crystallization behaviors of pure PLA and PLA/graphene nanocomposites from the melt were investigated by differential scanning calorimetry (DSC). The results showed that the graphene could play a role as a heterogeneous nucleating agent during the non-isothermal crystallizing process of PLA, and accelerate the crystallization rate. The non-isothermal crystallizing data were analyzed with the Avrami, Ozawa and Mo et al. models and the crystallization parameters of the samples were obtained. It is demonstrated that the combination of the Avrami and Ozawa models developed by Mo et al. was successful in describing the non-isothermal crystallization process for pure PLA and its nanocomposite. According to the Kissinger equation, the activation energies were found to be -154.3 and -179.5 kJ/mol for pure PLA and PLA/0.1 wt% graphene nanocomposite, respectively. Furthermore, the spherulite growth behavior was investigated by polarized optical microscopy (POM) and the results also supported the DSC data.

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Isothermal Crystallization Behavior and Kinetics of Poly (lactic acid) Filled with a Novel Nucleating Agent

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.887-888.716 ◽

2014 ◽

Vol 887-888 ◽

pp. 716-722

Author(s):

Nai Xu ◽

Xing Hui Wang ◽

Li Sha Pan ◽

Su Juan Pang ◽

Xuan Chen ◽

...

Keyword(s):

Lactic Acid ◽

Isothermal Crystallization ◽

Crystallization Behavior ◽

Nucleating Agent ◽

Poly Lactic Acid ◽

Scanning Calorimetry ◽

Nucleation Effect ◽

Amide Derivatives ◽

Aromatic Amide ◽

Kinetics Of

The crystallization behavior and crystalline structure of poly (lactic acid) (PLA) filled with a novel nucleating agent (TMC328), which is a kind of aromatic amide derivatives, were investigated using differential scanning calorimetry (DSC) and wide angle X-ray (XRD). In isothermal crystallization from the melt, the present of TMC328 remarkably affected the isothermal crystalline behaviors of PLA. PLA/0.5% TMC328 sample exhibited very short crystallization half-times at 90-130 °C. Furthermore, the Avrami theory was used to describe the isothermal crystallization kinetics of PLA/TMC328 samples. It is confirmed that TMC328 showed a significant heterogeneous nucleation effect on the crystallization of PLA matrix. Moreover, XRD measurement indicates that TMC328 is a kind of α-form nucleating agent for PLA.

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