ISSN:
1436-2449
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Summary Phase behavior of poly(pyromellitimide)s having (n-alkyloxy)methyl side chains (-CH2OCmH2m+1, m=4, 6, 8) has been studied by wide angle X-ray scattering, differential scanning calorimetry and 13C solid-state NMR. While there are no observable transitions in the polymers bearing short side chain(m=4, 6), there is one transition in the polymer bearing the longest side chain(m=8), which is assigned to mesophase-mesophase transition. All the samples show layered mesophase at room temperature, in which the side chains are amorphous but the main chains form two-dimensional crystals in each layer. In the polymer bearing the longest side chain(m=8), it shows another layered mesophase at high temperature. In the high temperature mesophase, the main chains do not form two-dimensional crystals in each layer; only the lateral packing of the main chains remains undisrupted.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002890070028
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