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Macromolecules
Volumn 43, Issue 16, 2010, Pages 6542-6548
A new scenario of flow-induced shish-kebab formation in entangled polymer solutions
Author keywords

[No Author keywords available]
Indexed keywords

A-FRAMES; CHAIN ORIENTATION; CONCENTRATION FLUCTUATION; CRYSTALLINE SUPERSTRUCTURE; CUT OUT; ENTANGLED POLYMER SOLUTIONS; FIBER SPINNING; INNER REGION; KINETIC PATHWAY; LINEAR POLYETHYLENE; NITROGEN GAS FLOW; RAZOR BLADES; ROOM TEMPERATURE; SELF-ASSEMBLING PROCESS; SHISH-KEBABS; SIMPLE SHEAR FLOW; TIME EVOLUTIONS; TIME REGION; UHMW-PE; ULTRA-HIGH MOLECULAR WEIGHT;
EID: 77955740792     PISSN: 00249297     EISSN: None     Source Type: Journal    
DOI: 10.1021/ma100496g     Document Type: Article
Times cited : (66)
References (50)
  • 8
    • 77955736925 scopus 로고    scopus 로고
    • Ph.D. Thesis, California Institute of Technology
    • Fernandez-Ballester, F. Ph.D. Thesis, California Institute of Technology, 2007.
    • (2007)
    • Fernandez-Ballester, F.1
  • 37
    • 77955741277 scopus 로고    scopus 로고
    • It is a big surprise at first glance to note the similarity of the shear flow effects and the extensional flow effects on these structure evolutions, since these two flow geometries are known to have different effects on molecular orientation and stress evolution. However, we should note that the extensional flow field imposed on the fiber in the spinning line is complex because the extensional strain rate and stress depend on the distance Z from the spinneret along the spinning line, as expected from the Z dependence of birefringence, the fiber diameter, temperature, etc. (see for example refs 38 and 39). Consequently, it may be plausible that the elongational flow effects are still small in the position A (Z = 30 mm) and B (Z = 100 mm) near the spinneret, so that the birefringence and hence the chain orientation and stretching are negligibly small. This may explain the structure evolution at A and B similar to that shown in Figure 1 A under the simple shear flow
    • It is a big surprise at first glance to note the similarity of the shear flow effects and the extensional flow effects on these structure evolutions, since these two flow geometries are known to have different effects on molecular orientation and stress evolution. However, we should note that the extensional flow field imposed on the fiber in the spinning line is complex because the extensional strain rate and stress depend on the distance Z from the spinneret along the spinning line, as expected from the Z dependence of birefringence, the fiber diameter, temperature, etc. (see for example refs 38 and 39). Consequently, it may be plausible that the elongational flow effects are still small in the position A (Z = 30 mm) and B (Z = 100 mm) near the spinneret, so that the birefringence and hence the chain orientation and stretching are negligibly small. This may explain the structure evolution at A and B similar to that shown in Figure 1 A under the simple shear flow.
  • 40
    • 77955720759 scopus 로고    scopus 로고
    • It may be puzzling why the chains bridging the demixed domains are under tension, while the chains inside the domains are still in random coil. Although the generalization of the effect or expectation deserves future works, at this moment we expect that the demixed domains are only partially draining with the solvent flow; hence, the chains inside being kept essentially random coil and that motions of the demixed domains as a whole in the solvent flow cause the chains bridging the domains be stretched and self-assembled into the bundles. The bundles of the stretched chains may further grow toward the inside of the domains
    • It may be puzzling why the chains bridging the demixed domains are under tension, while the chains inside the domains are still in random coil. Although the generalization of the effect or expectation deserves future works, at this moment we expect that the demixed domains are only partially draining with the solvent flow; hence, the chains inside being kept essentially random coil and that motions of the demixed domains as a whole in the solvent flow cause the chains bridging the domains be stretched and self-assembled into the bundles. The bundles of the stretched chains may further grow toward the inside of the domains
  • 41
    • 77955765429 scopus 로고    scopus 로고
    • Here LMW and UHMW polymer species serve as "solvents" and "polymers", respectively, in light of phase separation mediated by the dynamic asymmetry effects. However, one should note the following important facts: the "LMW solvents" can cocrystallize with the "UHMW polymers" in both shishs and kebabs, (7) while the solvent, decalin or paraffin, in polymer solutions never cocrystallizes with polymer
    • Here LMW and UHMW polymer species serve as "solvents" and "polymers", respectively, in light of phase separation mediated by the dynamic asymmetry effects. However, one should note the following important facts: the "LMW solvents" can cocrystallize with the "UHMW polymers" in both shishs and kebabs, (7) while the solvent, decalin or paraffin, in polymer solutions never cocrystallizes with polymer.
  • 47
    • 77955727315 scopus 로고    scopus 로고
    • Doctoral Thesis, Kyoto University
    • Murase, H. Doctoral Thesis, Kyoto University, 2005.
    • (2005)
    • Murase, H.1

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.