Ethylene-carbon monoxide polymerization

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. 

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). 

Since the aforementioned investigations, significant advances in aqueous catalytic insertion polymerization have only been made over the past decade. Alternating copolymerization of olefins with carbon monoxide, polymerization of ethylene and 1-olefins, and polymerizations of norbomenes and of butadiene have been studied. 

Studies (90, 91) with Cr02/Si02 catalyst have shown that formation of a surface chromate takes place by reaction of Cr02 and surface silanol groups on silica (Reaction 17). Reaction of this chemisorbed chromate with ethylene results in an oxidation-reduction reaction (90-95) with formation of a low-valent chromium center (Reaction 18). Proposals for Cr(II) as the active site are based on studies of the catalyst after reduction by ethylene, carbon monoxide, or hydrogen. One study (93. 94) showed that the polymerization rate increased with the fraction of Cr(II) in the catalyst. Another study (92) showed by polarography that the chromium is reduced to a divalent state by ethylene. 

Subjects specifically excluded are cycloolefin polymerizations catalyzed by naked nickel catalysts, palladium-catalyzed ethylene/carbon monoxide alternating copolymerizations, metathesis polymerizations of cyclic olefins, and diene polymerizations... 

For ethylene-carbon monoxide copolymers, the formation of the free radical type I prcxlucts is suppressed to only about 10% of the total reactkms because both radicals are polymeric and hardly ever escape from the iimnediate environment On the other hand, for ethylene-methyl vinyl ketone copolymers, photolysis yields one polymeric and one small acetyl radical, with the effknency of type I reaction eight times as... 

The bulk polymerization of 1,2-dioximes with metals has been described (35). A polymer containing 1,2-dioxime groups, prepared by nitrosating an ethylene/carbon monoxide copolymer, was cross-linked by exchange at 200°C with tris(ethyl acetoacetato)aluminum to yield tough, insoluble films. 

Alloys of PVC prepared with high-molecular-weight ethylene-carbon monoxide (CO)-ester terpolymers are finding increasing use in PVC roofing membranes. To help offset some of the formulation costs, lower-cost branched phthalates such as DIDP or DPHP are being used as partial replacement of the linear phthalates and the ethylene-CO-ester-type polymeric plasticizers. 

The addition of alcohols to form the 3-alkoxypropionates is readily carried out with strongly basic catalyst (25). If the alcohol groups are different, ester interchange gives a mixture of products. Anionic polymerization to oligomeric acrylate esters can be obtained with appropriate control of reaction conditions. The 3-aIkoxypropionates can be cleaved in the presence of acid catalysts to generate acrylates (26). Development of transition-metal catalysts for carbonylation of olefins provides routes to both 3-aIkoxypropionates and 3-acryl-oxypropionates (27,28). Hence these are potential intermediates to acrylates from ethylene and carbon monoxide. 

Most chromium-based catalysts are activated in the beginning of a polymerization reaction through exposure to ethylene at high temperature. The activation step can be accelerated with carbon monoxide. Phillips catalysts operate at 85—110°C (38,40), and exhibit very high activity, from 3 to 10 kg HDPE per g of catalyst (300—1000 kg HDPE/g Cr). Molecular weights and MWDs of the resins are controlled primarily by two factors, the reaction temperature and the composition and preparation procedure of the catalyst (38,39). Phillips catalysts produce HDPE with a MJM ratio of about 6—12 and MFR values of 90—120. 

Polymerization. Carbon monoxide forms copolymers with ethylene and suitable vinyl compounds. No large-scale uses for the copolymers or their further reaction products such as polyalcohols and polyamines have been found (75). 

A series of tests [15] were conducted to compare three types of polymeric modifiers for PVC Du Ponf s Elva-loy 741, a copolymer of ethylene, vinylacetate, and carbon monoxide Goodyear s Chemigum P83, a copolymer of butadiene and acrylonitrile and 566TPU from our lab, a polyester-based TPU. Some of the results are provided in Tables 5 and 6. 

It has been shown by Barb and by Dainton and Ivin that a 1 1 complex formed from the unsaturated monomer (n-butene or styrene) and sulfur dioxide, and not the latter alone, figures as the comonomer reactant in vinyl monomer-sulfur dioxide polymerizations. Thus the copolymer composition may be interpreted by assuming that this complex copolymerizes with the olefin, or unsaturated monomer. The copolymerization of ethylene and carbon monoxide may similarly involve a 1 1 complex (Barb, 1953). 

Selective and reversible adsorption of gaseous molecules such as dioxygen, carbon monoxide, ethylene, acetylene, and dinitrogen have been performed by the use of suitable macromolecule-metal complexes. Selective adsorption of metal ions such as UO has also been studied using polymeric ligands. 

Although rings made of polyethylene work very well, as we have already found, polyethylene degrades extremely slowly in the environment. A small amount of carbon monoxide (CO) can be polymerized with ethylene to produce a copolymer that degrades in sunlight (undergoes photodegradation) ... 

The compatibility of blends of poly (vinyl chloride) (PVC) and a terpolymer (TP) of ethylene, vinyl acetate, and carbon monoxide was investigated by dynamic mechanical, dielectric, and calorimetric studies. Each technique showed a single glass transition and that transition temperature, as defined by the initial rise in E" at 110 Hz, c" at 100 Hz, and Cp at 20°C/min, agreed to within 5°C. PVC acted as a polymeric diluent which lowered the crystallization temperature, Tc, of the terpolymer such that Tc decreased with increasing PVC content while Tg increased. In this manner, terpolymer crystallization is inhibited in blends whose value of (Tc — Tg) was negative. Thus, all blends which contained 60% or more PVC showed little or no crystallinity unless solvent was added. 

TVy blending with any one of a multitude of additives, PVC can be transformed into a broad spectrum of resins ranging from highly plasticized to impact resistant. The use of polymeric plasticizers has attracted a great deal of attention because they provide superior permanence in physical properties over their low molecular weight counterparts. Recently a terpolymer of ethylene, vinyl acetate, and carbon monoxide was reported to be miscible with PVC (1,2). The system is of interest because blends of PVC and ethylene-vinyl acetate copolymers range from incompatible to miscible, depending on the content of vinyl acetate in the copolymer (3,4,5). We have therefore undertaken x-ray,... 

More industrial polyethylene copolymers were modeled using the same method of ADMET polymerization followed by hydrogenation using catalyst residue. Copolymers of ethylene-styrene, ethylene-vinyl chloride, and ethylene-acrylate were prepared to examine the effect of incorporation of available vinyl monomer feed stocks into polyethylene [81]. Previously prepared ADMET model copolymers include ethylene-co-carbon monoxide, ethylene-co-carbon dioxide, and ethylene-co-vinyl alcohol [82,83]. In most cases,these copolymers are unattainable by traditional chain polymerization chemistry, but a recent report has revealed a highly active Ni catalyst that can successfully copolymerize ethylene with some functionalized monomers [84]. Although catalyst advances are proving more and more useful in novel polymer synthesis, poor structure control and reactivity ratio considerations are still problematic in chain polymerization chemistry. 

SAFETY PROFILE A poison by subcutaneous route. Questionable carcinogen with experimental tumorigenic data. Catalyzes the potentially explosive polymerization of ethylene oxide. Explosive reaction when heated with guanidinium perchlorate. Reaction with carbon monoxide may form an explosive product. Potentially violent reaction with hydrogen peroxide. 

---