摘要
The liquid crystallinity of poly(N-vinylcarbazole) was studied by using powder X-ray diffraction, polarized opticalmicroscopy, and differential scanning calorimetry. The results show that the lower molecular weight fractions of this polymerdo not form a liquid crystalline phase, while the samples of sufficiently high molecular weight do form a mesophase attemperatures above the glass transition. The lowest value of the degree of polymerization for PVK to form a stable liquidcrystalline phase was found to be in the range of 150 to 200, significantly higher than the value of 50 for most conventionalside chain liquid crystaline polymers.
The liquid crystallinity of poly(N-vinylcarbazole) was studied by using powder X-ray diffraction, polarized optical microscopy, and differential scanning calorimetry. The results show that the lower molecular weight fractions of this polymer do not form a liquid crystalline phase, while the samples of sufficiently high molecular weight do form a mesophase at temperatures above the glass transition. The lowest value of the degree of polymerization for PVK to form a stable liquid crystalline phase was found to be in the range of 150 to 200, significantly higher than the value of 50 for most conventional side chain liquid crystalline polymers.
基金
This work was supported by the National Natural Science Foundation (Grant no. 59873001)
