| Summary: | 碩士 === 國立臺灣大學 === 化學研究所 === 88 === A series of PDMS/PHMS/PMPS random copolymer were Synthesized in one step through acid catalyzed ring-opening polymerizations. Using D4, D3~4Ph and D4~5H as comonomers, trifluoromethanesulfonic acid (CF3SO3H) as catalyst, hexamethyldisiloxane(M2) as molecular weight regulator, a series of random copolymers with different composition(-MeHSiO- unit content 10mol%~50mol% and -MePhSiO- unit content 0mol%~50mol%) were synthesized. The products were characterized by GPC and 29Si-NMR. The Mn of the products ranges in 4.3K~12.1K and the polydispersities(Mw/Mn) is about 1.8~2.8.
By using 29Si-NMR, not only the composition but also the monomer sequence of the copolymers were determined. DSC and TGA were used to study the thermal properties of the copolymers. It was found that by introducing the phenyl-containing siloxane unit to the backbone, the glass transition temperature arising regularly and the thermal stability(T50) also increased.
In optical characteristics, it was found that the refractive index(nD) is 1.39~1.40 in PDMS/PHMS copolymers, while after introducing the -MePhSiO- unit to the polymer backbone, the refractive index(nD) is increased by 0.1.
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