Highly Enhanced Crystallization Kinetics of Poly(l-lactic acid) by Poly(ethylene glycol) Grafted Graphene Oxide Simultaneously as Heterogeneous Nucleation Agent and Chain Mobility Promoter

2015 ◽  
Vol 48 (14) ◽  
pp. 4891-4900 ◽  
Author(s):  
Jia-Zhuang Xu ◽  
Zi-Jing Zhang ◽  
Huan Xu ◽  
Jing-Bin Chen ◽  
Rong Ran ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Lactic Acid ◽  
Ethylene Glycol ◽  
Crystallization Kinetics ◽  
Heterogeneous Nucleation ◽  
Poly Ethylene Glycol ◽  
Nucleation Agent ◽  
Chain Mobility ◽  
Poly Ethylene ◽  
Kinetics Of

scholarly journals Non-Isothermal Crystallization Kinetics of Poly(Ethylene Glycol)–Poly(l-Lactide) Diblock Copolymer and Poly(Ethylene Glycol) Homopolymer via Fast-Scan Chip-Calorimeter

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1156
Author(s):  
Dejia Chen ◽  
Lisha Lei ◽  
Meishuai Zou ◽  
Xiaodong Li
Keyword(s):  
Ethylene Glycol ◽  
Heterogeneous Nucleation ◽  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Poly Ethylene Glycol ◽  
Ozawa Method ◽  
Isothermal Crystallization Kinetics ◽  
Fast Cooling ◽  
Poly Ethylene ◽  
Kinetics Of

The non-isothermal crystallization kinetics of double-crystallizable poly(ethylene glycol)–poly(l-lactide) diblock copolymer (PEG-PLLA) and poly(ethylene glycol) homopolymer (PEG) were studied using the fast cooling rate provided by a Fast-Scan Chip-Calorimeter (FSC). The experimental data were analyzed by the Ozawa method and the Kissinger equation. Additionally, the total crystallization rate was represented by crystallization half time t1/2. The Ozawa method is a perfect success because secondary crystallization is inhibited by using fast cooling rate. The first crystallized PLLA block provides nucleation sites for the crystallization of PEG block and thus promotes the crystallization of the PEG block, which can be regarded as heterogeneous nucleation to a certain extent, while the method of the PEG block and PLLA block crystallized together corresponds to a one-dimensional growth, which reflects that there is a certain separation between the crystallization regions of the PLLA block and PEG block. Although crystallization of the PLLA block provides heterogeneous nucleation conditions for PEG block to a certain extent, it does not shorten the time of the whole crystallization process because of the complexity of the whole crystallization process including nucleation and growth.

Uniformly Dispersed Poly(ethylene glycol) Functionalized Graphene Oxide/Poly(L-lactic acid) Nanocomposites with Balanced Mechanical Properties

2015 ◽  
Vol 815 ◽  
pp. 583-588
Author(s):  
Zi Jing Zhang ◽  
Yan Ni Zhou ◽  
Huan Liu ◽  
Le Min Zhu ◽  
Zhong Ming Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Lactic Acid ◽  
Ethylene Glycol ◽  
High Performance ◽  
Gravimetric Analysis ◽  
Poly Ethylene Glycol ◽  
Functionalized Graphene Oxide ◽  
Strong Interfacial Interaction ◽  
Poly Ethylene

Balanced mechanical properties are always the goal of high-performance general plastics for engineering purposes. In order to develop uniformly dispersed graphene oxide/poly(L-lactic acid) nanocomposites with balanced mechanical properties, a poly(ethylene glycol) (PEG) grafted graphene oxide was introduced into poly(L-lactic acid) (PLLA) matrix. The PEG grafted graphene oxide (GEG) was confirmed by the results of fourier transform infrared (FTIR) spectra and thermal gravimetric analysis (TGA). Then the mechanical properties of the nanohybrids were measured. The results showed that in contrast to the aggregation of GO, GEG could uniformly disperse in PLLA matrix. An intriguing phenomenon is that thanks to the strong interfacial interaction between GEG and PLLA, it exhibits a substantial enhancement of the elongation at break (EB) as well as a simultaneous improvement of the tensile strength (TS), while the addition of GO decreases the EB of PLLA matrix. This work provides a potential industrialized technique for high-performance PLLA nanocomposites

scholarly journals Chemically Reduced Graphene Oxide-Reinforced Poly(Lactic Acid)/Poly(Ethylene Glycol) Nanocomposites: Preparation, Characterization, and Applications in Electromagnetic Interference Shielding

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 661 ◽  
Author(s):  
Ahmad Fahad Ahmad ◽  
Sidek Ab Aziz ◽  
Zulkifly Abbas ◽  
Suzan Jabbar Obaiys ◽  
Khamirul Amin Matori ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Lactic Acid ◽  
Ethylene Glycol ◽  
Reduced Graphene Oxide ◽  
Electromagnetic Interference ◽  
Poly Lactic Acid ◽  
Electromagnetic Interference Shielding ◽  
Poly Ethylene Glycol ◽  
Reduced Graphene ◽  
Poly Ethylene

In this study, a nanocomposite of reduced graphene oxide (RGO) nanofiller-reinforcement poly(lactic acid) (PLA)/poly(ethylene glycol) (PEG) matrix was prepared via the melt blending method. The flexibility of PLA was improved by blending the polymer with a PEG plasticizer as a second polymer. To enhance the electromagnetic interference shielding properties of the nanocomposite, different RGO wt % were combined with the PLA/PEG blend. Using Fourier-transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM) and X-ray diffraction, the structural, microstructure, and morphological properties of the polymer and the RGO/PLA/PEG nanocomposites were examined. These studies showed that the RGO addition did not considerably affect the crystallinity of the resulting nanomaterials. Thermal analysis (TGA) reveals that the addition of RGO highly improved the thermal stability of PLA/PEG nanocomposites. The dielectric properties and electromagnetic interference shielding effectiveness of the synthesized nanocomposites were calculated and showed a higher SE total value than the target value (20 dB). On the other hand, the results showed an increased power loss by increasing the frequency and conversely decreased with an increased percentage of filler.

scholarly journals Isothermal Crystallization Kinetics of Poly(ethylene oxide)/Poly(ethylene glycol)-g-silica Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 648
Author(s):  
Xiangning Wen ◽  
Yunlan Su ◽  
Shaofan Li ◽  
Weilong Ju ◽  
Dujin Wang
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Poly Ethylene Glycol ◽  
Isothermal Crystallization Kinetics ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Kinetics Of

In this work, the crystallization kinetics of poly(ethylene oxide) (PEO) matrix included with poly(ethylene glycol) (PEG) grafted silica (PEG-g-SiO2) nanoparticles and bare SiO2 were systematically investigated by differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM) method. PEG-g-SiO2 can significantly increase the crystallinity and crystallization temperature of PEO matrix under the non-isothermal crystallization process. Pronounced effects of PEG-g-SiO2 on the crystalline morphology and crystallization rate of PEO were further characterized by employing spherulitic morphological observation and isothermal crystallization kinetics analysis. In contrast to the bare SiO2, PEG-g-SiO2 can be well dispersed in PEO matrix at low P/N (P: Molecular weight of matrix chains, N: Molecular weight of grafted chains), which is a key factor to enhance the primary nucleation rate. In particular, we found that the addition of PEG-g-SiO2 slows the spherulitic growth fronts compared to the neat PEO. It is speculated that the interfacial structure of the grafted PEG plays a key role in the formation of nuclei sites, thus ultimately determines the crystallization behavior of PEO PNCs and enhances the overall crystallization rate of the PEO nanocomposites.

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