Study of the assembled morphology of aryl amide derivative and its influence on the nonisothermal crystallizations of isotactic polypropylene

Dong, Mengyao; Guo, Zhao‐Xia; Yu, Jian; Su, Zhiqiang

doi:10.1002/polb.21642

Cited by 83 publications

(77 citation statements)

References 51 publications

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“…Thus, the iPP/iPP‐5 samples had the highest density of the β‐form crystals in all of the samples at a cooling rate of 3°C/min. In the literature, it was shown that β‐form crystals could be formed under some special conditions, such as with the addition of a β‐nucleating agent, directional crystallization at certain temperature gradients, and shearing or elongation of the melt during crystallization . In our case, the nearby polymer chains were oriented by the transcrystalline crystallization of the polymer chains for the first.…”

Section: Resultsmentioning

confidence: 63%

Crystallization and mechanical properties of isotactic polypropylene/calcium carbonate nanocomposites with a stratified distribution of calcium carbonate

Wang

Lü

Peng

et al. 2013

J of Applied Polymer Sci

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Isotactic polypropylene (iPP)/calcium carbonate (CaCO3) nanocomposites with a stratified distribution of CaCO3 were prepared by two‐step molding. The iPP and CaCO3 nanoparticles were first mixed by a batch mixer and then compressed into thin layers. Thin iPP/CaCO3 layers alternating with thin neat iPP layers were finally compressed together to form the stratified samples. The transcrystals were observed in the stratified samples by polarized optical microscopy and scanning electron microscopy. The transcrystals grew from the surfaces of the filled layers and occupied most of the space in the neat iPP layers. The β‐form crystals were found in the stratified samples with thick transcrystalline layers, whereas the thickness of the transcrystalline layer was dependent on the content of CaCO3 nanoparticles and the cooling rate of the processing. The relative crystallinity index of the conventional samples first increased and then decreased with the content of CaCO3 nanoparticles. However, the relative crystallinity index of the stratified samples deceased slightly with the content of CaCO3 nanoparticles because of the stratified distribution of the CaCO3 nanoparticles. The stratified samples, except for the samples with high β‐form contents, became more brittle than the conventional samples because of the transcrystal formation in the iPP layers. The stratified samples with high β‐form contents showed much better mechanical properties than the conventional samples. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39632.

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Section: Resultsmentioning

confidence: 63%

Crystallization and mechanical properties of isotactic polypropylene/calcium carbonate nanocomposites with a stratified distribution of calcium carbonate

Wang

Lü

Peng

et al. 2013

J of Applied Polymer Sci

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“…The β-NA aryl amides derivative (trade name TMB-5, powder) with a melt temperature of 197°C was provided by Fine Chemicals Department of Shanxi Provincial Institute of Chemical Industry, China. It has been reported in the literatures that TMB-5 has chemical structure similar to N,N′-dicyclohexyl-2,6-naphthalene-dicarboxamide (commercial name NJS) [40,41].…”

Section: Methodsmentioning

confidence: 99%

Crystallization behavior of isotactic polypropylene induced by competition action of β nucleating agent and high pressure

Yang

Chen

et al. 2011

Colloid Polym Sci

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Addition of β-form nucleating agent (β-NA) to isotactic polypropylene (iPP) can greatly induce the variation of the crystallization of matrix. Here, we introduce high pressure to the crystallization process of β-NA nucleated iPP. It is observed that there is a competition between the effect of high pressure and the nucleation effect of β-NA on crystallization of iPP. With the increasing of high pressure, both the contents of β-iPP and α-iPP decrease while the content of γ-iPP increases. A novel crystalline morphology of γ-iPP with the fragmentations of γ-spherulites regularly organized in a local region is observed. Namely, γ-spherulites grow on the lateral of β-NA needlelike structure. The dual nucleation effects of the special needlelike structure of β-NA towards β/α-iPP and the effect of high pressure which prevents the growth of β-iPP but promotes the growth of γ-iPP are the main mechanisms for the novel crystalline morphology of γ-iPP. Specifically, the mixed polymorphic β/γ-iPP can be achieved under a certain pressure. This possibly enlarges the application of iPP material.

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“…However, up to now, the researchers mainly focus on the influence of the DS‐ β ‐NA (such as concentration) and the thermal conditions (fusion temperature, cooling rates, etc. ) and PP molecular weights . In the aspect of stereo‐defect distribution (tacticity distribution), the nucleating mechanism and influence of DS‐ β ‐NA on the dynamic crystallization and melting behavior of PP with different stereo‐defect distribution are still not clear as far as we concerned.…”

Section: Introductionmentioning

confidence: 91%

Investigation on the dynamic crystallization and melting behavior of β‐nucleated isotactic polypropylene with different stereo‐defect distribution—the role of dual‐selective β‐nucleation agent

Kang

Wang

Peng

et al. 2013

Polymers for Advanced Techs

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The selectivities of different β‐nucleating agents might be quite different from each other, which is important in determining the crystallization and properties of the obtained β‐isotactic polypropylene (β‐iPP). However, the relationship between molecular structure and dynamic crystallization behavior of β‐iPP nucleated by dual‐selective β‐nucleating agent (DS‐β‐NA) is still not clear. In this study, the dynamic crystallization and melting behavior of two β‐iPP with nearly same average isotacticity but different stereo‐defect distribution, nucleated by a DS‐β‐NA (N,N′‐dicyclohexyl‐2,6‐naphthalenedicarboxamide; trade name TMB‐5), were studied by differential scanning calorimetry, wide‐angle X‐ray diffraction, and scanning electronic microscopy. The results indicated that in the presence of TMB‐5, the dynamic crystallization and melting behavior of the samples are quite different because the joint effects of the dual selectivity of TMB‐5 and stereo‐defect distribution of the iPP under different cooling rates. Two important roles were observed: (i) slow cooling rate favors the formation of high β‐fraction; and (ii) high crystallization temperature favors the crystallization of α‐phase accelerated by TMB‐5. Generally, the dual selectivity of the DS‐β‐NA, the stereo‐defect distribution of iPP, and the cooling rate were important factors in determining the formation of β‐crystal. Copyright © 2013 John Wiley & Sons, Ltd.

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Study of the assembled morphology of aryl amide derivative and its influence on the nonisothermal crystallizations of isotactic polypropylene

Cited by 83 publications

References 51 publications

Crystallization and mechanical properties of isotactic polypropylene/calcium carbonate nanocomposites with a stratified distribution of calcium carbonate

Crystallization and mechanical properties of isotactic polypropylene/calcium carbonate nanocomposites with a stratified distribution of calcium carbonate

Crystallization behavior of isotactic polypropylene induced by competition action of β nucleating agent and high pressure

Investigation on the dynamic crystallization and melting behavior of β‐nucleated isotactic polypropylene with different stereo‐defect distribution—the role of dual‐selective β‐nucleation agent

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