Catalytic curing and improved pyrolytic conversion of poly(methylcarbosilane)

POLY 142

So-Yeun Kim, baha8@naver.com1, Myoung-Hee Kim, 9878002@hanmail.net1, You-Jeong Kim, okkie52@hanmail.net1, Hee-Gweon Woo, hgwoo@chonnam.ac.kr1, Do-Heyoung Kim2, Bo-Hye Kim, magarett@hanmail.net3, Jin Jun, jinjun@dsu.ac.kr4, and Mi-Kyung Han, mi-han@northwestern.edu5. (1) Department of Chemistry, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju, 500-757, South Korea, (2) Faculty of Applied Chemical Engineering, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju, South Korea, (3) Department of Korean Medicinal Supply, Dongshin University, Naju, 520-714, South Korea, (4) Department of Optometry and Optic Science, Dongshin Universiy, Naju, 520-714, South Korea, (5) Department of Chemistry, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208
The poly(methylsilene) (1) was prepared in high yield by Wurtz coupling of dichlrordimethysilane, followed by Kumada rearrangment. The preceramic polymer 1 was modified by the group 4 metallocene Cp2MCl2/Red-Al (M = Ti, Zr, Hf) combination catalysts to produce the highly cross-linked insoluble polymers and the lowly cross-linked soluble polymers, respectively. Any marked trend toward molecular weight and TGA ceramic residue yield with metal within the respective group was not observed. The polymers modified with the group 4 metallocene combination catalysts possess higher molecular weight and lower percent ceramic residue yield than the polymers modified with the group 4 metallocene combinations appear to be higher than those of group 6 metal carbonyl catalysts at 100 oC in the dehydrocoupling of the poly(methlysilene). However, the catalytic activities of group 4 metallocene combinations appear to be lower than those of group 6 metal carbonyls at high temperature in the pyrolytic transformation of the modified poly(methylsilene). The pyrolysis of the modified poly(methylsilene) yielded SiC ceramic in improved ceramic yield.
 

General Papers: Functional Materials
6:00 PM-8:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Polymer Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007