Abstract
Two series of monomers, namely n-1-bromo-\\[4-(4-nitrophenylazo)phenyloxy]alkanes (Bn, n2, 3, 4, 5, 6, 8, 10) and N - n -\\[4-(4-nitrophenylazo)phenyloxy]alkyl diethanolamines (C n, n 3, 5, 6, 10), were synthesized and characterized. Their thermal behaviour was studied by differential scanning calorimetry (DSC), wide angle X-ray diffractometry (WAXD) and polarizing optical microscopy (POM) equipped with a hot stage. The results showed that the B n s (n6) exhibit monotropic nematic liquid crystalline behaviour; no liquid crystalline phase was found for the B ns (n6), while for the C ns, enantiotropic smectic liquid crystallinity for n 5, 6, 10 was seen, and for n 3 monotropic smectic phases were found. This different phase behaviour between B n and C n compounds is attributed to their different end groups. The FTIR analysis of C n indicated that there exists an intermolecular hydrogen bond between hydroxy groups, so that more stable liquid crystalline phase are formed. The effect of the length of the flexible chain on the thermal behaviour is also discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
