Crystallization kinetics and nanoparticle ordering in semicrystalline polymer nanocomposites

Altorbaq, Abdullah S.; Krauskopf, Alejandro A.; Wen, Xiangning; Pérez-Camargo, Ricardo A.; Su, Yunlan; Wang, Dujin; Müller, Alejandro J.; Kumar, Sanat K.

doi:10.1016/j.progpolymsci.2022.101527

Cited by 27 publications

(35 citation statements)

References 184 publications

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“…Dashed lines correspond to the two general observed regimes: NP-dominated regime (black curve) and brush-controlled regime (red curve). The NP dispersion states of the reported works are shown in the legend as well-dispersed (WD), connected-sheets (CS), strings (S), and aggregated (Agg) structures …”

Section: Resultsmentioning

confidence: 99%

“…This paper compares the nucleation efficiency of LNPs against that achieved by inorganic NPs (e.g., silica); we also examine their effect on decreasing spherulitic growth kinetics. Previous works have shown that inorganic NPs act as nucleating or antinucleating agents based on their dispersion states, surface chemistry, aspect ratio, and loadings. ,,,− That is, well-dispersed and surface-modified NPs can act as heterogeneous nucleation sites that lead to orders of magnitude increase in nucleation efficiency, as confirmed by various studies. , As aggregation usually occurs upon increasing NP concentration, the nucleation efficiency tends to decrease, resulting in an optimum at moderate loadings . In terms of growth kinetics, the incorporation of spherical NPs usually decreases the spherulite growth rate beyond a specific concentration .…”

Section: Introductionmentioning

confidence: 87%

“…In terms of growth kinetics, the incorporation of spherical NPs usually decreases the spherulite growth rate beyond a specific concentration . The extent of such decrease is mainly affected by NP content (interparticle spacing), surface chemistry, and NP aggregation . Altorbaq et al have shown that grafted NPs lead to a relatively larger decrease in the spherulitic growth rate compared to observations with bare NPs.…”

Section: Introductionmentioning

confidence: 93%

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Supernucleation Dominates Lignin/Poly(ethylene oxide) Crystallization Kinetics

et al. 2022

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The effect of lignin nanoparticles (LNPs) on the crystallization kinetics of poly(ethylene oxide) (PEO) is examined. Lignin from spruce and ionic isolation was used to prepare LNPs with a number-averaged diameter of 85 nm (with a relatively large polydispersity) by an ultrasonication method. PEO-based nanocomposites with four different LNP contents (5, 10, 15, and 20 wt %) were prepared and subject to isothermal and nonisothermal crystallization protocols in a series of experiments. Scanning electron microscopy (SEM) images showed welldispersed LNPs in the crystallized PEO matrix. The incorporation of LNPs exponentially increases nucleation density at moderate loadings, with this trend apparently saturating at higher loadings. However, the spherulitic growth rate decreases monotonically with LNP loading. This is attributed to the substantial PEO/LNP affinity, which impacts chain diffusion and induces supernucleation effect (with efficiencies in the order of 200%), but leads to slower growth rates. The overall crystallization kinetics, measured by the DSC, shows faster nanocomposite crystallization rates relative to the neat PEO at all LNP contents examined. This indicates that the supernucleation effect of LNPs dominates over the decrease in the growth rates, although its influence slightly decreases as the LNP content increases. The strong hydrogen-bonded interactions between the LNPs and the PEO are thus reminiscent of confinement effects found in polymer-grafted NP nanocomposites (e.g., PEO-g-SiO 2 / PEO) in the brush-controlled regime.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 93%

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Supernucleation Dominates Lignin/Poly(ethylene oxide) Crystallization Kinetics

et al. 2022

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“…The interactions between the nanofiller and the polymeric matrix in nanocomposites can have different effects on the Frontiers in Soft Matter frontiersin.org crystallization kinetics and on the melting behavior, as recently reviewed (Altorbaq et al, 2022). Often, the fillers will nucleate the polymer matrix as evidenced by the higher nucleation density, higher T c , and faster crystallization kinetics (compared to the neat polymer) without affecting its melting behavior.…”

Section: Nanocomposites: Super-nucleation Anti-nucleation and Pre-fre...mentioning

confidence: 99%

Recent applications of the Successive Self-nucleation and Annealing thermal fractionation technique

Pérez-Camargo

Cavallo²,

Müller³

2022

Front. Soft. Matter

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Successive Self-nucleation and Annealing (SSA) is a thermal fractionation technique that is performed by Differential Scanning Calorimetry (DSC). The combination of non-isothermal and isothermal steps applied during SSA achieves efficient molecular segregation during polymer crystallization. Such molecular segregation magnifies the effect of defects in polymer chain crystallization, thereby providing information on chain structure. The technique was created and implemented by Müller and co-workers in 1997, becoming a powerful resource for studying ethylene/α-olefin copolymers. The different variables to design the SSA protocol: fractionation window, fractionation time, scanning rate, sample mass, and the first self-nucleation temperature to be applied (Ts, ideal), have been previously reviewed, together with the different applications of SSA. SSA versatility, simplicity (when properly applied), and short times to produce results have allowed its use to study novel and more complex polymeric systems. This review article explores the most recent applications of SSA of the past decade. First, the principles of the technique are briefly explained, covering all the relevant variables. Next, we have selected different cases that show how SSA is employed in various novel fields, such as studying intermolecular interactions and topological effects in homopolymers; supernucleation and antinucleation effects in nanocomposites, including the pre-freezing phenomenon; crystallization modes in random copolymers; solid-solid transitions; miscibility, co-crystallization and composition in blends; evaluation of polymer synthesis variables; and the novel information that could be gained by using fast scanning chip-based calorimetry. Finally, we offer a perspective on SSA, a technique that has become a powerful method for studying the distribution of defects affecting crystallization in semi-crystalline polymers.

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“…Because phase separation in polymer blends and NP aggregation in PNCs are prevalent, the mechanical properties of these systems are often severely diminished. Therefore, it is believed that compatibilization is vital to improve the desired properties. − …”

Section: Introductionmentioning

confidence: 99%

Crystallization Kinetics and Mechanical Properties of Miscible Polymer Blend Nanocomposites: Linear versus Grafted Systems

et al. 2022

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We systematically investigate the effects of adding ungrafted PMMA versus silica-grafted PMMA (PMMA-g-SiO2) on the crystallization kinetics and the mechanical properties of PEO. In the grafted analogue, PMMA chains were grown from the surface of 14 nm diameter silica nanoparticles at a grafting density of ∼0.42 chain/nm2. The molecular weight of the PMMA was varied systematically (20–85 kDa), and the extent of confinement was regulated by varying the PEO fraction. While the PEO crystallinity and the crystal growth rate in the ungrafted and grafted systems track each other, the grafted systems exhibit enhanced crystallization kinetics, most likely because of faster chain dynamics. Additionally, the grafted systems have higher nucleation rates, especially for shorter PMMA chains. These differences in crystallization kinetics are likely due to the dry-brush zone near the silica surface, where graft chains do not interpenetrate with the matrix. In the context of mechanical properties, both additives enhance the PEO modulus and toughness, with the PMMA-g-SiO2 filled materials undergoing their brittle-to-ductile transition at lower loadings. Surprisingly, there is little difference between the two additives in how they affect PEO crystallization and mechanical propertiesthis is likely due to the high grafting densities where the core is effectively shielded from the PEO matrix.

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Crystallization kinetics and nanoparticle ordering in semicrystalline polymer nanocomposites

Cited by 27 publications

References 184 publications

Supernucleation Dominates Lignin/Poly(ethylene oxide) Crystallization Kinetics

Supernucleation Dominates Lignin/Poly(ethylene oxide) Crystallization Kinetics

Recent applications of the Successive Self-nucleation and Annealing thermal fractionation technique

Crystallization Kinetics and Mechanical Properties of Miscible Polymer Blend Nanocomposites: Linear versus Grafted Systems

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