| abstract |
ABSTRACT OF THE DISCLOSURE: A Langmuir-Blodgett ultrathin membrane is constituted of polyfumarate having a degree of polymerization of 20 to 10,000. The polyfumarate is obtained by polymerizing fumarate represented by the general formula of: wherein at least one of R1 and R2 represents a bulky hydrocarbon group such as a branched alkyl group, a cycloalkyl group or a substituent thereof, a fluorine-substituted hydrocarbon group, a hetero atom-containing hydrocarbon group or a silicon-containing group. |