From catalytic polymerization

Properties Liquid. D 0.770 (20/20C), boiling range 183-218C, bulk d 6.44 lb/gal (15.5). Combustible. Derivation Olefin fraction obtained from catalytic polymerization of propylene. 

Cycloaliphatic Diene CPD—DCPD. Cycloatiphatic diene-based hydrocarbon resias are typically produced from the thermal or catalytic polymerization of cyclopeatadieae (CPD) and dicyclopentadiene (DCPD). Upon controlled heating, CPD may be dimerized to DCPD or cracked back to the monomer. The heat of cracking for DCPD is 24.6 kJ / mol (5.88 kcal/mol). In steam cracking processes, CPD is removed from C-5 and... 

Washing light hydrocarbons with water is a common refinery practice. It finds application on the feed to catalytic polymerization plants. It is used to remove any entrained caustic from the mercaptan removal facilities as well as any other impurities such as amines which tend to poison the polymerization catalyst. Another use for water wash is in alkylation plants to remove salts from streams, where heating would tend to deposit them out and plug up heat exchanger surfaces. Water washing can be carried out in a mixer- settler, or in a tower if more intimate contacting is necessary. 

Thermal initiation makes an appreciable contribution to the polymerization rate for styrene at very low initiator concentrations, as we have pointed out earlier. Since the rate Rp includes contributions from thermal as well as from catalytic initiation, the second term in Eq. (36) remains valid provided the thermal initiation involves monoradicals. Diradical initiation, if it occurred, would introduce a deviation, since it produces no chain ends. 

Unlike CO, it is possible to polymerize isocyanides (R—N=C), isoelectronic analogs to CO. When R is a bulky group, such as tert-Bu, the polymer forms a stable helical structure. Asymmetric catalytic polymerization has been reported for t-Bu-NC using [Ni(T 3-allyl)(iV-trifluoroacetyl-proline)]2 providing (M)-helical polymer with 69% ee. The more stable helical polymer was prepared from 1,2-diisocya-nobenzene derivative initiated by a chiral Pd complex. (See Scheme 4.19.)... 

Phenolic compounds have also been oxidatively polymerized to humic substances by clay minerals (29) and by the mineral fraction of a latasol (66). After a 10-day equilibration period, montmoril-lonite and illite clay minerals yielded 44 to 47% of the total added phenolic acids as humic substances whereas quartz gave only 9%. Samples of a latasol yielded over 63% of the total amount, from mixtures in varied proportion, of mono-, di- and trihydroxy phenolic compounds as humic substances (66). Extractions of the reaction products yielded humic, fulvic, and humin fractions that resembled soil natural fractions in color, in acid-base solubility, and in infrared absorption spectra. Wang and co-workers (67) further showed that the catalytic polymerization of catechol to humic substances was, enhanced by the presence of A1 oxide and increased with pH in the 5.0 to 7.0 range. Thus the normally very reactive products of Itgnin degradation can be linked into very stable humic acid polymers which will maintain a pool of potentially reactive phytotoxins in the soil. 

In refining, the polymerization process is utilized to produce high-octane gasoline components from three- and four-carbon olefins. It can also be used for the production of certain alcohols and aromatic compounds. Cumene and ethyl benzene can be produced through catalytic polymerization. 

Products from the catalytic polymerization process are primarily dimers, trimers, tetramers, and oligomers rather than true polymers. However the process name is still used throughout the refining industry. 

Correlations presented in the middle thirties enabled the prediction of octane number improvement resulting from thermal reforming (7, 21). They have continued to appear in the literature (6, 20). Improvement of the octane number of naphthas has been the principal function of thermal reforming, but Egloff (8) discusses its usefulness also for the production of light olefins which provide feed stocks for alkylation or polymerization processes. To show the distinct improvement in the yield-octane relationship realized by the catalytic polymerization of C3 and C4 olefins produced by thermal reforming, Mase and Turner (16) present experimental data at various reforming severities for two naphthas. 

The chemical industry manufacturers a large variety of semiciystalline ethylene copolymers containing small amounts of or-olefins. These copolymers are produced in catalytic polymerization reactions and have densities lower than those of ethylene homopolymers known as high density polyethylene (HDPE). Ethylene copolymers produced in catalytic polymerization reactions are usually described as linear ethylene polymers, to distinguish them from ethylene polymers containing long branches which are produced in radical polymerization reactions at high pressures. 

From the Finemann-Ross plot of the data in Table II, monomer reactivity ratios are determined. riK = 0.654, r2/K = 1.09. The copolymer composition diagram is shown in Figure 3, which includes both spontaneous and catalytic polymerization to prove the similarity of both mechanisms. 

The first instance involves the Pt(II) fragment "TpPdMe," used not as a catalyst, but rather as a protecting function for alkynes during catalytic, and indeed stoichiometric, processes, a role that followed from the noted stability of TpPtMe(r 2-RC=CR) complexes, and their capacity to release the alkyne by carbonylation.56 63 Thus, ji-complexes with a series of bis (amide)acetylenes (144-149, Scheme 12, Section III.B.l), formed from the polymeric TpPtMe (126), could be subjected to conditions of catalytic hydrogenation, or basic hydrolysis of the pendant functions, without... 

Source Reprinted from Shindo, H., and Huang, R M. (1985a). Catalytic polymerization of hydroquinone by primary minerals. Soil Set 139, 505-511, with permission from Lippincott Williams Wilkins. 

Figure 2.19. SEM micrographs of hydroquinone polymers in the supernatant and mineral particles settled in the tephroite system at the ratio of mineral to hydroquinone solution of 0.01 at the initial pH of 6.0 at the end of 7 days, (a-c) hydroquinone polymers (d) tephroite particles after reaction with hydroquinone. Bar in Figure 2.19a =10pm bars in Figure 2.19b-d =2pm. Reprinted from Shindo, H., and Huang, P. M. (1985a). Catalytic polymerization of hydroquinone by primary minerals. Soil Sci. 139, 505-511, with permission from Lippincott Williams Wilkins.

Hydrogen sulfide may be removed from polymerization feed stock by scrubbing with ethanolamine or sodium hydroxide. When the mercaptan content of the feed is sufficiently high to give a Doctor-sour polymer, a regenerative caustic wash usually is inserted in the feed-preparation train to remove them. Mercaptan scrubbers ordinarily are not necessary on polymerization feed streams from catalytic-cracking units, but are required on feeds produced from sour crudes by thermal cracking. 

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