Abstract
Three biphenyl-containing vinyl ether monomers: 2-(4-biphenyloxy)ethyl vinyl ether (I), 2-(4-biphenylcarboxyl)ethyl vinyl ether (II), and 2-(4′-methoxy-4-biphenyloxy)ethyl vinyl ether (III), were cationically polymerized with the hydrogen iodide/iodine (HI/I2) initiator system to form living polymers with narrow molecular weight distributions. The thermal properties of the polymers were determined by DSC and by visual observations of samples placed on a hot stage on a polarizing microscope. Polymer I and Polymer II formed only isotropic melts, but Polymer III showed enantiotropic, liquid-crystalline (LC) behavior, and formed both smectic and nematic phases after one heating and cooling cycle. For comparison, polymers were also prepared with boron trifluoride etherate (BF3OEt2) as the initiator. Polymer III obtained with this initiator had a much broader molecular weight distribution and formed only a nematic phase. At approximately the same molecular weight, this sample also had a much higher isotropization temperature than the narrow distribution sample of Polymer III.
Sign-in/Register to access full text options 
Free) 
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 call
