Memory effect in isothermal crystallization of syndiotactic polypropylene --Role of melt structure and dynamics?

Maus, Andreas; Hempel, E; Thurn‐Albrecht, Thomas; Saalwächter, Kay

doi:10.1140/epje/i2007-10183-6

Cited by 61 publications

(47 citation statements)

References 47 publications

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“…Polymer single crystals (PSCs) with their uniform thicknesses, dimensions, and homogeneous chemical and physical properties are a special kind of ultrathin films . The principle method for single crystal preparation was the self‐seeding procedure . Compared to organic small molecule semiconductor crystals, there is very limited literature on polymer semiconductor single crystals or highly crystalline self‐assembled nanostructures .…”

Section: Introductionmentioning

confidence: 99%

“…[5,6] The principle method for single crystal preparation was the self-seeding procedure. [7][8][9] Compared to organic small molecule semiconductor crystals, [10,11] there is very limited literature on polymer semiconductor single crystals or highly crystalline self-assembled nanostructures. [12,13] The optoelectronic effects in semicrystalline conjugated polymers depend sensitively on chain order and the way crystalline domains are interconnected and oriented.…”

Section: Introductionmentioning

confidence: 99%

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High‐Quality Nano/Micro Hairy Single Crystals Developed from Poly(3‐hexylthiophene)‐Based Conductive–Dielectric Block Copolymers Having Flat‐on and Edge‐on Orientations

Zenoozi

Agbolaghi

Gheybi

et al. 2017

Macro Chemistry & Physics

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Highly uniform and conductive single crystals of poly(3‐hexylthiophene) (P3HT)‐based homo and block copolymers with the end coily blocks of polystyrene, poly(methyl methacrylate), and poly(ethylene glycol) are developed using self‐seeding method from varied quality solvents. Edge‐on and flat‐on orientations are detected depending on the thickness and width of single crystals. Coily blocks are excluded from the P3HT crystalline structures, leading to brush‐like or hairy regions on surface of grown single crystals in the longitude of P3HT chains. The larger single crystals possessing flat‐on orientation are obtained from weaker solvents at higher seeding temperatures. The longer P3HT chains are folded, however, the shorter backbones are laminated on each other. The highest backbone lamination occurs for homo‐P3HT7150 (Mn of P3HT = 7150 g mol−1) single crystals grown at 20 °C from anisole, the weakest employed solvent. In contract, highly ordered and folded hairy single crystals are acquired from better solvents and high molecular weight P3HTs. In these conditions, the crystallographic features of the hairy block copolymer single crystals are similar to those of nonhairy homo‐P3HT ones. The coily brush‐covered P3HT48 800 single crystals have more foldings compared to the homo‐P3HT48 800 ones, whereas only two laminated backbones in shorter P3HT blocks are detected.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

High‐Quality Nano/Micro Hairy Single Crystals Developed from Poly(3‐hexylthiophene)‐Based Conductive–Dielectric Block Copolymers Having Flat‐on and Edge‐on Orientations

Zenoozi

Agbolaghi

Gheybi

et al. 2017

Macro Chemistry & Physics

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“…At this T max , the crystalline order vanishes to an extent that the material appears isotropically from the macroscopic point of view; crystalline regions cannot be detected, neither by calorimetry, nor by nuclear magnetic resonance, nor by microscopic techniques. [37][38][39][40][41] It is still a matter of controversy whether some local chain orientation or even tiny crystallites survive under the applied melting conditions. In any case, these remaining structural entities considerably support nucleation when the material is subsequently cooled down to the respective crystallization temperature.…”

Section: Introductionmentioning

confidence: 99%

Equilibrium Melting Temperature of Poly(ferrocenyl dimethylsilane) in Homopolymers and Lamellar Diblock Copolymers with Polystyrene

Bellas

Jungnickel

et al. 2010

Macro Chemistry & Physics

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The equilibrium melting temperature, Tm,0, of poly(ferrocenyl dimethylsilane) (PFDMS) is re‐investigated using two PFDMS homopolymers and a PS‐b‐PFDMS copolymer (PS: polystyrene). The melting temperatures of samples crystallized at different crystallization temperatures, Tc, were found to depend in a nonlinear fashion on Tc. Consequently, the Hoffmann–Weeks approach fails in determining Tm,0. The more reliable Gibbs–Thomson approach results in a Tm,0 = (215 ± 11) °C for the PFDMS homopolymers, and a Tm,0 = (179 ± 5) °C for the PFDMS microphases in the lamellar PS‐b‐PFDMS diblock copolymer.magnified image

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“…These remnant ordered domains in the melt act as nucleation sites, resulting in fast crystallization rates, because of a decrease in the free energy barrier for nucleation from entropic considerations . Such behavior is widely understood as a result of “melting memory effect” …”

Section: Introductionmentioning

confidence: 99%

“…[6,7] Such behavior is widely understood as a result of "melting memory effect". [8][9][10][11][12][13][14] One peculiar example of memory effect in the melt can be associated with the phase transition from β-phase to α-phase in isotactic polypropylene (iPP) during heating. Varga, [15] Lotz, and coworkers [16] studied in detail this transition process of βto α-phase.…”

Section: Introductionmentioning

confidence: 99%

Enhanced beta to alpha recrystallization in beta isotactic polypropylene with different thermal histories

Lyu

Cavallo

et al. 2019

Polymer Crystallization

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A small but meaningful increase in the content of β‐crystals was observed in β‐nucleated isotactic polypropylene (iPP) samples isothermally crystallized at high temperature and then cooled to room temperature. The secondary crystallization of these crystals could also be linked to a distinct exothermic effect revealed by differential scanning calorimetry upon cooling. These crystals constituted of thinner lamellae certainly show earlier melting upon reheating, with respect to the isothermally crystallized fraction. As such, the enhancement in βα recrystallization in iPP cooled below 100°C is attributed to the formation of a self‐nucleated or partially ordered melt upon melting of these crystals, which induces the fast nucleation and growth of the α‐phase, because of larger undercooling with respect to the β‐phase at elevated temperatures. On the other hand, the recrystallization of the β‐phase from partially molten β‐iPP samples is tentatively assigned to homo‐epitaxial nucleation on the surface of thicker β‐phase lamellae.

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Memory effect in isothermal crystallization of syndiotactic polypropylene --Role of melt structure and dynamics?

Cited by 61 publications

References 47 publications

High‐Quality Nano/Micro Hairy Single Crystals Developed from Poly(3‐hexylthiophene)‐Based Conductive–Dielectric Block Copolymers Having Flat‐on and Edge‐on Orientations

High‐Quality Nano/Micro Hairy Single Crystals Developed from Poly(3‐hexylthiophene)‐Based Conductive–Dielectric Block Copolymers Having Flat‐on and Edge‐on Orientations

Equilibrium Melting Temperature of Poly(ferrocenyl dimethylsilane) in Homopolymers and Lamellar Diblock Copolymers with Polystyrene

Enhanced beta to alpha recrystallization in beta isotactic polypropylene with different thermal histories

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