Ethylene carbon monoxide polymers

Norrish type I chemistry is claimed to be responsible for about 15% of the chain scission of ethylene—carbon monoxide polymers at room temperature, whereas at 120°C it promotes 59% of the degradation. Norrish I reactions are independent of temperature and oxygen concentration at temperatures above the T of the polymer (50). 

Quantum, by contrast, converted an ethylene—carbon monoxide polymer into a polyester-containing terpolymer by treatment with acidic hydrogen peroxide, the Baeyer-Villiger reaction (eq. 11). Depending on the degree of conversion to polyester, the polymer is totally or partially degraded by a biological mechanism. 

Photodegradation may involve use of inherently photo-unstable polymers or the use of photodegradant additives. An example of the former are ethylene-carbon monoxide polymers in which absorption of light by the ketone group leads to chain scission. The polymer becomes brittle and forms a powder. Such materials are marketed by Dow and by Du Pont. Other examples are the copolymers of divinyl ketone with ethylene, propylene or styrene marketed by Eco Atlantic. 

Polymer Photochemistry. The occurrence of these reactions in polymeric ketones was first demonstrated by Guillet and Norrish (6, 7), who studied poly (methyl vinyl ketone) in solution and showed that the main features of the photodegradation could be accounted for quantitatively on the basis of Type I and Type II reactions. The conclusion was later confirmed by Wissbrun (13). Recent studies of the ethylene-carbon monoxide polymer (9) confirm that both Type I and Type II reactions occur. The Type I reaction results in the formation of two polymer radicals, one of which is an acyl radical which may subsequently decarbonyl-ate (Reaction 4). 

The authors express their appreciation to the National Research Council of Canada, Dunlop Research Ltd., Tennessee Eastman Co., and the Paint Research Institute for financial assistance. The Tennessee Eastman Co. kindly supplied samples of ethylene-carbon monoxide polymers and 2-hydroxy-4-dodecyloxybenzophenone. 

Shell is already producing ethylene/carbon monoxide polymers using a palladium-based SSC by a slurry phase process. BP and GE are working on similar technologies for the production of E/CO polymers. Norbornene and other cyclic olefins are very interesting and potentially low cost monomers that could be... 

Ethylene-carbon monoxide polymers offer superior performance as high-strength fibres for aramide tyre cord, but at a significantly lower cost. Their structure is more compatible with rubber than steel, polyester, or PA tyre reinforcements. 

The blending of polymeric organic carbonyl compounds, e.g., ethylene/carbon monoxide copolymer, with the parent polymer, e.g., polyethylene, gives a plastic film material that degrades within 3 months. 

Other uses of blends include controlled rate of fertilizer release(77) based on ethylene/vinyl acetate/carbon monoxide polymers which is U.V. sensitive, polyolefin blends with any biodegradable polymers,(78) and polyolefins blended with metals and autoxidizable substrates. (79) Doane and co-workers(80) at the U.S.D.A. have used grafted starches in many applications, including soil stabilization. 

Chatani, Y., T. Tazikawa, S. Mcrahashi, Y. Sakata, and Y. Nishimura Crystal structure of polyketone (1 1 ethylene/carbon monoxide) copolymer. J. Polymer Sci. 55, 811 (1961). 

Furans have also been incorporated (76USP3979367) into the main chains of polymers by modification of ethylene-carbon monoxide interpolymers in analogous fashion to the pyrroles (Section 1.11.4.1.1). The interpolymer was simply treated with acid in a solvent, and magnesium sulfate was added to react with the water formed in the cyclization. As with the pyrroles, the furan units were introduced to improve thermal processing. 

Harlan G, Kmiec C (1995) Ethylene-carbon monoxide copolymers. In Scott G, Gilead D (eds) Degradable polymers principles and applications. Chapman Hall, London, chap 8... 

For photolysis of the ethylene—carbon monoxide copolymer in solution, the AH-6 lamp and a 20-mm. path-length quartz cell were used. The cell was filled with the solvent, pure n-heptane, and the intensity of the lamp was measured at the experimental temperature. Freeze-dried polymer was then added to make a 2% solution, which absorbed about 25% of the light. The polymer was dissolved, and the solution was mixed by a dry nitrogen stream, which also flushed out any air dissolved in the solvent. The light beam was then allowed to enter the cell, and the photolysis commenced the intensity of the emergent beam was monitored by the photomultiplier tube and the recorder. At the end of the photolysis the cell was filled with pure solvent, and the intensity of the lamp was measured again. The polymer was recovered from solution by evaporating the heptane it was then dissolved in benzene and freeze-dried. 

The 1% ethylene-carbon monoxide copolymer was also irradiated in the solid phase (thin film). Compression-molded films were fixed on plates which fitted into the Perkin Elmer 521 infrared spectrophotometer. An infrared spectrum of the polymer could thus be obtained after each period of photolysis without disturbing the film. For photolyses at room temperature and above the plates were mounted in a solid brass cell through which a stream of inert gas could be passed while the cell was being heated. 

In practice, the CO units constitute less than 5% of the total polymer. Figure 9-2 shows the very rapid decrease in molar mass for an ethylene-carbon monoxide copolymer exposed to a constant source of UV radiation (Harlan and Kmiec... 

Harlan, G., and C. Kmiec. 1995. Ethylene-carbon monoxide copolymers. In Degradable polymers Principles and applications, eds. G. Scott and D. Gilead, 159. New York, NY Chapman and Hall. 

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