In:
Journal of Polymer Science Part B: Polymer Physics, Wiley, Vol. 44, No. 17 ( 2006-09), p. 2412-2424
Abstract:
The conformational characteristics of a comb‐like side‐chain liquid crystal polysiloxane (SCLCP), dissolved in deuterated chloroform, were evaluated by small‐angle neutron scattering (SANS) measurements over a wide q range. SANS studies were carried out on specimens with constant backbone length (DP = 198) and variable spacer length ( n = 3, 5, and 11), and with constant spacer length ( n = 5) and variable DP (45, 72, 127, and 198). The form factor P ( q ) at high q was analyzed using the wormlike chain model with finite cross‐sectional thickness ( R c ) and taking into account the molecular weight polydispersity. The analysis generated values of persistence length in the range l p = 28–32 Å, considerably larger than that of the unsubstituted polysiloxane chain ( l p = 5.8 Å), with contour lengths per monomer comparable to the fully‐extended polysiloxane backbone ( l m = 2.9 Å). This indicates a relatively rigid SCLCP chain due to the influence of the densely attached mesogenic groups. The SCLCP with n = 11 is more flexible ( l p = 28 Å) than those with n = 3 and n = 5 ( l p = 32 Å). The cross‐sectional thickness increases with spacer length, R c ∼ n 0.21±0.02 (3 ≤ n ≤ 11), and the contour length per monomer decreases with increasing spacer length, l m ∼ n −0.35±0.01 . © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2412–2424, 2006
Type of Medium:
Online Resource
ISSN:
0887-6266
,
1099-0488
Language:
English
Publisher:
Wiley
Publication Date:
2006
detail.hit.zdb_id:
1473448-5
