Preferential Incorporation of Azelaic Acid Units into the Crystalline Phase of the Copoly(Alkylene Dicarboxylate) Derived from 1,9-Nonanediol and an Equimolar Mixture of Pimelic and Azelaic Acids

Díaz, Angélica; Casas, María Teresa; Puiggalı́, Jordi

doi:10.3390/polym7091486

Cited by 4 publications

(1 citation statement)

References 39 publications

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“…In polymer crystallization, the formation of stacks of correlated lamellar crystals, i.e. an assembly of crystalline lamellae, all oriented parallel to each other, has been observed quite frequently . Surprisingly, although the lamellae in such stacks are separated by amorphous interlayers resulting from chain folding, the orientation of these lamellae was found to be in crystallographic registry .…”

Section: Introductionmentioning

confidence: 99%

A nucleation mechanism leading to stacking of lamellar crystals in polymer thin films

Majumder

Poudel

Zhang

et al. 2019

Polymer International

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Systematic studies based on well-controllable model systems aim at understanding how crystallization from a melt or solution of randomly coiled polymers leads to the formation of mono-lamellar crystals. However, besides mono-lamellar crystals also various other morphologically simple but yet not well understood structures are found. In particular, stacks of correlated lamellar crystals have been observed since the early days of the study of polymer crystallization. Here, we demonstrate that a recently proposed mechanism of self-induced nucleation within lamellar crystals provides a possibility to explain how in such stacks lamellar crystals can be correlated. Examining various polymer systems, we show that the probability for generating self-induced nuclei depends on the morphology of an initiating dendritic basal lamellar crystal. In addition, we provide evidence that this self-induced nucleation mechanism, together with a high rate of transport of molten polymer to the fold surface, may allow the formation of polymer crystals with similar size in all three dimensions, containing a large number of superposed correlated lamellae.

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Section: Introductionmentioning

confidence: 99%

A nucleation mechanism leading to stacking of lamellar crystals in polymer thin films

Majumder

Poudel

Zhang

et al. 2019

Polymer International

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Unique isodimorphism and isomorphism behaviors of even-odd poly(hexamethylene dicarboxylate) aliphatic copolyesters

Sang

Wei

et al. 2017

Polymer

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Three series of even-odd aliphatic copolyesters, poly(hexamethylene gluarate-co-hexamethylene pimelate) (PHGP), poly(hexamethylene pimelate-co-hexamethylene azelate) (PHPA), and poly(hexamethylene gluarate-co-hexamethylene azelate) (PHGA), were firstly synthesized derived from even diol of 1,6-hexanediol with odd diacids of glutaric acid, pimelic acid or azelaic acid, respectively. Then, their cocrystallization behaviors were systematically investigated by DSC, WAXD, and POM techniques. It is found that both PHGP and PHPA showed isodimorphism with a characteristic eutectic behavior observed from the plot of melting point versus composition, however, PHGA exhibited strict isomorphism in the whole composition range without a eutectic point. WAXD studies also confirmed the unique isodimorphism and isomorphism behaviors for even-odd copolyesters. The only slight change of the methylene number in alkyl unit of comonomers could generate so large difference in crystallization behavior, which exhibits unique physicochemical properties and structure-properties correlations in such even-odd copolyesters. Furthermore, the difference in cocrystallization miscibility effect of comonomers was analyzed by thermodynamics based on the defect Gibbs energy calculated from Wendling-Suter model. For PHGP and PHPA, the comonomer units have better miscibility in the case of the incorporation of shorter unit into the longer unit crystal than the opposite case. By contrast, in the case of PHGA, the HG and HA units are perfectly miscible in a same crystal lattice with only a little difference in crystal cell dimensions due to the identity of chain conformation of HG and HA units during packing into the crystal lattice. Finally, a model of crystal lattice structure of copolyesters was proposed to better understand the difference in cocrystallization miscibility effect of comonomers between isodimorphism and isomorphism.

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Growth Kinetics of Stacks of Lamellar Polymer Crystals

et al. 2018

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Most theoretical concepts of polymer crystallization have evolved around monolamellar single crystals as model systems. However, such approaches do not account for an important and unique aspect of crystallization of long flexible molecules: the correlated stacking of lamellar crystals. In our experimental work, we focus on the growth kinetics of such stacks of lamellae in thin films of poly(nonadecane methylphosphonate). Interestingly, concurrent with a decrease in lateral lamellar growth, we observed an increase in vertical growth, that is, an increase in the number of stacked crystalline lamellae. Intriguingly, in contrast to lateral lamellar growth, the rate of such vertical growth increased with decreasing degree of undercooling. Moreover, we show the possibility of forming three-dimensional polymer quasi-single crystals. Some of the formed stacks of lamellar crystals were about 100 times thicker than the initial film; that is, they had a thickness of about 20 times the contour length of the polymer and contained about 800 stacked lamellae. We propose that growth kinetics of stacking of lamellae is governed by (i) the probability of forming self-induced nuclei, (ii) the detachment probability of crystalline stems, and (iii) the influx of molten polymers toward the growth front.

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Preferential Incorporation of Azelaic Acid Units into the Crystalline Phase of the Copoly(Alkylene Dicarboxylate) Derived from 1,9-Nonanediol and an Equimolar Mixture of Pimelic and Azelaic Acids

Cited by 4 publications

References 39 publications

A nucleation mechanism leading to stacking of lamellar crystals in polymer thin films

A nucleation mechanism leading to stacking of lamellar crystals in polymer thin films

Unique isodimorphism and isomorphism behaviors of even-odd poly(hexamethylene dicarboxylate) aliphatic copolyesters

Growth Kinetics of Stacks of Lamellar Polymer Crystals

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