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Author Lee, Jong Kwan ♦ Im, Jeong Eun ♦ Lee, Kwang Hee
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©2004
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences
Subject Keyword poly(ethylene terephthalate) ♦ polycarbonate ♦ crystallization ♦ crystallizationsecondary crystallization ♦ Polymer Sciences ♦ Soft and Granular Matter, Complex Fluids and Microfluidics ♦ Physical Chemistry ♦ Characterization and Evaluation of Materials ♦ Nanochemistry ♦ Nanotechnology
Abstract We have studied the lamellar-level morphology of poly(ethylene terephthalate) (PET)/polycarbonate (PC) blends using small-angle X-ray scattering (SAXS). Measurements were made as a function of the holding time in the melt. We determined the morphological parameters at the lamellar level by correlation function analysis of the SAXS data. An increased amorphous layer thickness was identified in the blend, indicating that some PC was incorporated into the interlamellar regions of PET during crystallization. The blend also exhibits a larger lamellar crystalline thickness (l $_{ c }$) than that of pure PET. A possible reason for the increase inl $_{ c }$ is that the inclusion of the PC molecules in the interlamellar regions causes an increase in the surface free energy of folding. At the early stage of isothermal crystallization, we observed a rapid drop in the value ofl $_{ c }$ in the blend; this finding indicates that a relatively large fraction of secondary crystals form during the primary crystallization. In contrast, the value ofl $_{ c }$ for the sample that underwent a prolonged holding time increased with time in the secondary crystallization-dominant regime; this observation suggests that the disruption of chain periodicity, which results from transesterification between the two polymers, favors the development of fringed micellar crystals that have larger values ofl $_{ c }$, rather than the development of normal chain-folded crystals.
ISSN 15985032
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2004-01-01
Publisher Place Berlin, Heidelberg
e-ISSN 20927673
Journal Macromolecular Research
Volume Number 12
Issue Number 2
Page Count 6
Starting Page 172
Ending Page 177

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Source: SpringerLink