Sciencemadness Discussion Board

CO2 Based Polymer

ShadowWarrior4444 - 14-7-2008 at 20:47

The History Channel--not somewhere one might expect to see a 'How-It-Works' style show, however one has premiered there. The episode in question detailed various processes for garbage disposal and recovery. (Show name: "The Works")

Now, for the main item of interest: Polymers containing "42% by weight CO2" according to the people making it. (Inside who's lab we were shown.) The process apparently proceeds from gaseous CO2 and Propylene Oxide using a new catalyst cleverly referred to as "pixie dust." The visual accompanying this was what appeared to be a translucent plastic storage bottle (perhaps LDPE, or PP) containing an orange-red powder that was for demonstration liberally added to the reaction chamber.

The host described the process as being like a "chemical zipper," the lab-inhabitant stating that normally CO2 is stable, but together with this catalyst it has enough energy to be added to the polymer.

Not that I am particularly trusting of TV show explanations, however the concept seemed interesting. Any opinions? (Or hopefully relevant patents/journals.)

not_important - 14-7-2008 at 21:00

Quote:
Catalysts for the reactions of epoxides and carbon dioxide

Oxiranes and carbon dioxide are known to cycloadd and/or copolymerize in the presence of a variety of catalysts. Indeed, cyclic carbonates are prepared on a technical scale by coupling epoxides and carbon dioxide. The fact that cyclic carbonate formation represents one of the few examples of successful carbon dioxide utilization, coupled with the high reactivity of epoxides, has resulted in many papers which reveal a remarkable variety of active catalysts for the CO2/epoxide coupling processes. Catalysts include simple alkali metal salts, ammonium salts, phosphines, main-group metal complexes, and both non-oxidative and oxidative transition-metal complexes. The purpose of this review is to compile the different catalysts into their general groups of similarity, with the hopes of shedding light on some of the important differences in reaction pathways. There generally appears to be a lack of detailed mechanistic studies; therefore, it is hoped that this review will emphasize where mechanistic clarification is most importantly needed. Furthermore, we anticipate that this review will provide insight into cyclic carbonate vs. polycarbonate production from the CO2/epoxide coupling process.

doi:10.1016/0010-8545(95)01232-X



http://www.sciencedirect.com/science?_ob=ArticleURL&_udi...
Quote:

Macromolecules 1986, 19, 8-13
Takuzo Aida, Masahide Ishikawa, and Shohei Inoue

Alternating Copolymerization of Carbon Dioxide and Epoxide
Catalyzed by the Aluminum Porphyrin-Quaternary Organic Salt
or -Triphenylphosphine System. Synthesis of Polycarbonate with Well-Controlled Molecular Weight



Quote:

Journal of Polymer Science Part A: Polymer Chemistry
Volume 41 Issue 22, Pages 3549 - 3555
Hiroshi Sugimoto , Hiromitsu Ohshima, Shohei Inoue

The first successful example of the formation of polycarbonate from 1-atm carbon dioxide and epoxide was demonstrated by the alternating copolymerization of carbon dioxide and epoxide with manganese porphyrin as a catalyst. The copolymerization of carbon dioxide and cyclohexene oxide with (porphinato)manganese acetate proceeded under the 1-atm pressure of carbon dioxide to give a copolymer with an alternating sequence.


DOI 10.1002/pola.10835
Quote:
Journal of Polymer Science: Polymer Chemistry Edition
Volume 17 Issue 2, Pages 415 - 423
Kazuo Soga, Kazuya Uenishi, Sakuji Ikeda

The homopolymerization of propylene oxide was first conducted at 80°C in the absence of any solvent by using various metal salts of acetic acid and it was found that Mg(OAc)2, Cr(OAc)3, Mn(OAc)2, Co(OAc)2, Ni(OAc)2, Zn(OAc)2, and Sn(OAc)2 were effective for the polymerization. The copolymerization of propylene oxide and carbon dioxide was next examined by using these effective metal salts of acetic acid as catalysts. Most of these were effective also for the copolymerization. The nature of the polymer obtained was strongly dependent on the catalyst used. Co(OAc)2 and Zn(OAc)2 gave an alternate copolymer of propylene oxide and carbon dioxide, Mg(OAc)2, Cr(OAc)3, and Ni(OAc)2 gave a random copolymer, while Sn(OAc)2 gave a homopolymer of propylene oxide. Then the copolymerization of propylene oxide and carbon dioxide was kinetically investigated in some detail by using Co(OAc)2 as a catalyst. On the basis of the results obtained, a plausible mechanism was proposed for both the homopolymerization of propylene oxide and copolymerization of propylene oxide and carbon dioxide.


DOI 10.1002/pol.1979.170170211