Ethylene—carbon monoxide copolymers

Other patents include copolymers of vinyl ketones with acrylates, methacrylates, and styrene (53) an ethylene—carbon monoxide (1—7 wt %) blend... 

Random ethylene-carbon monoxide copolymers have been known for many years and have properties somewhat similar to low density polyethylene. Alternating ECO copolymers were first produced long ago by Reppe of BASF in... 

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. 

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. 

Alternating copolymers of ethylene with olefins containing double bonds in the cis configuration, like ds-2-butene, cyclopentene, cycloheptene,115 and norbomene,116 have been described. Recently also copolymers of carbon monoxide with styrene and styrene derivatives, having syndiotactic117 and isotactic118 configurations, have been synthesized and characterized. 

Ethylene carbonate, 10 640, 665 in lithium cells, 3 459 molecular formula, 6 305t physical properties, 6 306t transesterification of, 13 651-652 Ethylene-carbon monoxide (ethylene-CO) copolymers, 5 9 10 197 Ethylene chlorohydrin process, 10 640 Ethylene-chlorotrifluoroethylene (E-CTFE) alternating copolymer (ECTFE), 15 248... 

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). 

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... 

In the case of ethylene/carbon monoxide copolymerisation with nickel- and palladium-based catalysts, a strictly alternating high molecular weight copolymer is formed (average molecular weight in the range 10 x 103 100 x 103).When more developed catalysts are used, the copolymerisation conditions can be mild a temperature of 25 °C combined with a pressure of ca 20 atm. The obtained copolymer, poly(ethylene-c// -carbon monoxide), poly(l-oxytrimethylene)... 

Styrene and ring-substituted styrenes also form copolymers with carbon monoxide, similarly to ethylene and a-olefins. These styrene/carbon monoxide copolymers are of alternating, highly regioregular head-to-tail structure and are characterised by different stereoregularity (syndiotactic, isotactic) [115-117]. 

Analogously to ethylene-carbon monoxide copolymers, alternating copolymers between cycloolefins such as norbornene and carbon monoxide have been synthesised using cationic Pd(II) complexes modified by phosphorus ligands such as [Pd(MeCN)n(PPh)4 J[BF4]2( = 1,2,3) [27]. General requirements for the... 

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. 

Figure 4. Absorption spectrum of ethylene-carbon monoxide (1%) copolymer in heptane at 80°C.

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... 

Figure 9-2. Decrease in molar mass for low-density polyethylene and ethylene-carbon monoxide copolymer on exposure to UV radiation (Harlan 1995).

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. 

Carilon Ethylene-carbon monoxide altern. Copolymer Shell... 

The products described above were selected in order to illustrate some of the principles associated with the enhancement of sunlight sensitivity. There are, in addition, other examples ( ) of the copolymer approach, e.g., ethylene/carbon monoxide, and the additive approach. 

During the following 15 years, only small advances were achieved in increasing catalyst efficiencies. Independently, Fenton [9a] at Union Oil and Nozaki [9b] at Shell Development Company (USA) discovered several related palladium chlorides, palladium cyanides, and zero-valent palladium complexes as catalysts. Sen and co-workers [10] reported that cationic bis(triphenyl-phosphine)-palladium tetrafluoroborate complexes in aprotic solvents such as dichloromethane, produced ethylene/carbon monoxide copolymers under very mild conditions. The reaction rates were, however, very low, as were the molecular weights. 

A number of reviews of topical interest have appeared with degradable plastics making a come back. These include the role of plastics in the environment " and agricultural film , ethylene carbon monoxide copolymers and their analysis. Several other topic reviews of interest relate to the role of titanium dioxide pigments 22 laser ablation and photolysis, degradation and stabilisation of polyolefins , conformation defects in poly(vinyl chloride)and poly(ethylene terephthalate) photooxidation . 

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