Bulk-Surface Modification of Nanoparticles for Developing Highly-Crosslinked Polymer Nanocomposites

Jouyandeh, Maryam; Ganjali, Mohammad Reza; Aghazadeh, Mustafa; Habibzadeh, Sajjad; Formela, Krzysztof; Saeb, Mohammad Reza

doi:10.3390/polym12081820

Cited by 11 publications

(5 citation statements)

References 57 publications

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“…Table 1 suggests that increasing β from 5 to 15 °C min −1 increased both T P and Δ H , as expected from previous investigations [ 48 ]. The presence of Mica and Mica-IM in the epoxy nanocomposites causes a reduction in the T onset , which is a signature of the facilitation of the cure, except for the first rate of heating, 5 °C min −1 .…”

Section: Resultssupporting

confidence: 87%

Epoxy/Ionic Liquid-Modified Mica Nanocomposites: Network Formation–Network Degradation Correlation

et al. 2021

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We synthesized pristine mica (Mica) and N-octadecyl-N’-octadecyl imidazolium iodide (IM) modified mica (Mica-IM), characterized it, and applied it at 0.1–5.0 wt.% loading to prepare epoxy nanocomposites. Dynamic differential scanning calorimetry (DSC) was carried out for the analysis of the cure potential and kinetics of epoxy/Mica and epoxy/Mica-IM curing reaction with amine curing agents at low loading of 0.1 wt.% to avoid particle aggregation. The dimensionless Cure Index (CI) was used for qualitative analysis of epoxy crosslinking in the presence of Mica and Mica-IM, while qualitative cure behavior and kinetics were studied by using isoconversional methods. The results indicated that both Mica and Mica-IM improved the curability of epoxy system from a Poor to Good state when varying the heating rate in the interval of 5–15 °C min−1. The isoconversional methods suggested a lower activation energy for epoxy nanocomposites with respect to the blank epoxy; thus, Mica and Mica-IM improved crosslinking of epoxy. The higher order of autocatalytic reaction for epoxy/Mica-IM was indicative of the role of liquid crystals in the epoxide ring opening. The glass transition temperature for nanocomposites containing Mica and Mica-IM was also lower than the neat epoxy. This means that nanoparticles participated the reaction because of being reactive, which decelerated segmental motion of the epoxy chains. The kinetics of the thermal decomposition were evaluated for the neat and mica incorporated epoxy nanocomposites epoxy with varying Mica and Mica-IM amounts in the system (0.5, 2.0 and 5.0 wt.%) and heating rates. The epoxy/Mica-IM at 2.0 wt.% of nanoparticle showed the highest thermal stability, featured by the maximum value of activation energy devoted to the assigned system. The kinetics of the network formation and network degradation were correlated to demonstrate how molecular-level transformations can be viewed semi-experimentally.

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Section: Resultssupporting

confidence: 87%

Epoxy/Ionic Liquid-Modified Mica Nanocomposites: Network Formation–Network Degradation Correlation

et al. 2021

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“…It is observed that the major decomposition reaction of PU occurs above 300 • C, which is attributed to degradation of soft segments. The minor weight loss in the range of 150 to 250 • C suggests degradation of hard segments and evaporation of volatile compounds [42][43][44][45]. Addition of nano-clay stabilized thermal decomposition of the matrix and the TGA curves of nanocomposites were very much similar to the one for pure PU.…”

Section: Resultsmentioning

confidence: 82%

Thermal-Resistant Polyurethane/Nanoclay Powder Coatings: Degradation Kinetics Study

et al. 2020

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In the present study, thermal degradation kinetics of polyurethane (PU) powder coatings reinforced with organo-modified montmorillonite (OMMT) was investigated. PU nanocomposites were prepared in different concentrations of 1, 3, and 5 wt.% of OMMT via the extrusion method. The microstructure of the nanocomposites was observed by scanning electron microscope (SEM) illustrating uniform dispersion of OMMT nano-clay platelets in the PU matrix except for the sample containing 5 wt.% nano-palates. Thermal degradation kinetics of the PU nanocomposite was investigated using thermogravimetric analysis (TGA) at different heating rates of 5, 10, and 20 °C/min. The results showed that the initial decomposition temperatures were shifted toward higher values (more than 40 °C for T5% and up to 20 °C for T10%) by introducing the nano-clay to the PU matrix. Friedman, Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), and modified Coats-Redfern iso-conversional methods were applied to model the decomposition reaction and the activation energy of the nanocomposite powder coatings. Overall, the presence of nano-clay increased the activation energy of the PU degradation up to 45 kJ/mol, when compared to the blank PU, which suggests very high thermal stability of nanocomposites. The Sestak-Berggren approach proposed a good approximation for the reaction model, especially at low temperatures. Thus, PU decomposition was detected as an autocatalytic reaction, which was suppressed by the barrier effect of OMMT nano-palates intercalated with polymer chains.

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“…For CDs, the broad bands between 3500 and 3000 cm −1 correspond to the stretching vibrations of O-H and N-H, respectively, 15 which can be utilized as connection points for PEG. Besides, C-H stretching vibrations at 2926 and 2876 cm −1 , CH 2 vibrations at 1465 and 1399 cm −1 , 16 C=O/C=C bonds at 1660 cm −1 , and C-N bonds at 1560 cm −117 could be observed in the FITR spectrum of the CDs (red line in Figure 1E). After connection with PEG, the FTIR spectrum of PEG-CDs (black line in Figure 1E) shows significant changes.…”

Section: Resultsmentioning

confidence: 91%

Carbon dots crosslinked gel polymer electrolytes for dendrite‐free and long‐cycle lithium metal batteries

et al. 2022

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Lithium metal batteries (LMBs) with extremely high energy densities have several advantages among energy storage equipment. However, the uncontrolled growth of dendrites and the flammable liquid electrolytes (LEs) often cause safety accidents. All solid-state batteries seem to be the ultimate choice, but solvent-free electrolytes usually fail in terms of conductivity at room temperature. Therefore, gel polymer electrolytes (GPEs) with a simple manufacturing process and high ionic conductivity are considered as the most competitive candidates to resolve the present difficulties. Herein, we design a polymeric network structure via esterification and amidation reactions between polyethylene glycol (PEG) and carbon dots (CDs). After incorporation with polyvinylidene fluoride and some LEs, the as-prepared PEG-CDs composite electrolytes (PCCEs) show a high ionic conductivity of 5.5 mS/cm and an ion transference number of 0.71 at room temperature, as well as good flexibility and thermostability. When the PCCEs are assembled with lithium metal anodes and LiFePO 4 or LiCoO 2 cathodes, both the cycling stability and the retention rate of these LMBs show excellent performance at room temperature.

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Bulk-Surface Modification of Nanoparticles for Developing Highly-Crosslinked Polymer Nanocomposites

Cited by 11 publications

References 57 publications

Epoxy/Ionic Liquid-Modified Mica Nanocomposites: Network Formation–Network Degradation Correlation

Epoxy/Ionic Liquid-Modified Mica Nanocomposites: Network Formation–Network Degradation Correlation

Thermal-Resistant Polyurethane/Nanoclay Powder Coatings: Degradation Kinetics Study

Carbon dots crosslinked gel polymer electrolytes for dendrite‐free and long‐cycle lithium metal batteries

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