Ethylene-carbon monoxide degradation

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. 

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. 

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... 

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. 

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 . 

Ethylene/carbon monoxide copolymers containing 2 or 3 wt. o carbon monoxide are photo degradable polymers with the same general processing properties as high pressure, low density polyethylene. Exposure to UV radiation causes decomposition. The polymer is essentially a low density polyethylene with an environmental feature. Commercialization of these materials took place in the late 1960s. 

Nakatsuka, S. and Andiady, A. (1994) Studies on enhanced degradable plastics. III. The effect of weathering of polyethylene and (ethylene-carbon monoxide) copolymers on moisture and carbon dioxide permeability. Journal... 

Mitsubishi [101] claimed a unique biodegradable polycarboxylate (Scheme 8) containing ethylene, carbon monoxide, and maleic anhydride monomers. The initial degradation step is photoactivation to yield low-molecular-weight fragments as indicated in Table 12.2. Unfortunately, no biodegradation data were reported on these fragments. 

The value of B (days" ) listed in Table 10.4 for films of LDPE, ethylene-carbon monoxide (1%) copolymer (ECO), and photodegradable LDPE (containing a metal catalyst pro-oxidant) quantify their rates of degradation. The ECO copolymer is the same as that used in photodegradable six-pack rings (and supplied by the manufacturer... 

Ethylene-Carbon Monoxide Copolymers (ECOs). These polymers are random copolymers of ethylene and carbon monoxide, with properties similar to low-density polyethylene. They are sold by Shell under the trade name Carilon. These polymers exhibit low water absorption and good barrier properties, but they are susceptible to UV degradation. They find application in packaging, fuel tanks, fuel hnes, and in blends. 

Other recent patents include copolymers of tdnyl ketones with acrylates, methacrylates, and styrene (O Brien, 1993) an ethylene/carbon monoxide (1-7 wt%) blend as a photo initiator in polycaprolactone/polyethylene blends (Hirsoe, 1992) ethylene/ carbon monoxide for degradable golf tees (Akimoto) a vinyl ketone analog of Exxon s carbon monoxide/dioxapane/ethylene (Priddy, 1992) a photodegradable food wrapper based on blends of a polyolefin/starch and photo activators for the... 

It is generally believed that ethylene-carbon monoxide copolymers because of their internal ketone group, degrade mainly by Norrish Type II chain scission reactions when subjected to ultraviolet radiation in the 290 nm region. The reaction has been found to be generally independent of temperature [3]. 

Harlan, G. M. and Nicholas, A. (1987) Degradable ethylene-carbon monoxide copolymer. Proceedings of Symposium on Degradable Plastics, SPI, Washington, DC, 10 June, pp. 14-17. 

Kmiec, C. (1990) Ethylene-carbon monoxide copolymer The established degradable plastic, RECYCLE 90, Forum and Exposition, Davos, Switzerland, 29-31 May. 

In the case of ethylene/carbon monoxide copolymer, the degradation occurs generally with the triplet state which exhibits the maximum lifetime and corresponds to a free-radical carried by flie carbonyl group. This radical evolves to give either... 

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