Polymers titanium

Butyl titanate polymers find use in surface coatings but as a class, titanium polymers lack hydrolytic stability. 

New porphyrin-containing Group IVB polymers were made using ricinoleic acid215 or hematoporphine IX.210,217,218 Polymer 93 is a representative example that was used as a selective chelating agent. Macrocyclic tetrapyrrole has four methyl, two ethanolic, and two propionic acid side chains. The polymers are cross-linked because of the four reactive functions (two acid and two alcohol groups). The adsorption of Ni+2 by porphyrin moieties was observed for the titanium polymer. 

An interesting variant of the polycondensation approach involved the use of fluorescent dyes as the difunctional organic monomers. Thus, soluble, high molecular weight titanium polydyes (e.g., 4/ = 5.3 x 10 by lightscattering measurements for the titanium polymer derived from the diphenol monomer bromophenol blue) were synthesized in yields that depended on the reaction conditions and the dye used. Structural characterization was... 

Fig. 9 UV-visible spectra of synthesized titanium/polymer nanocomposites Samples 8, 9, and 10 contain amorphous particles of Ti02, and samples 11 and 12 contain amorphous Ti...

The problem of determination of the number of active centers as the number of titanium-polymer bonds was formulated for the first time in the pioneering works of Natta [15, 146] for propylene polymerization on catalyst TiCls + AlEts. He used for this purpose cocatalyst AlEt3 labeled by a radioactive isotope in the ethyl group. Active centers of type Cl cTi- CH2CH3 are formed in this case and polymer with a radioactive label obtained on these centers. The number of active centers can be calculated from these data. 

Later, for definition of the number of active centers at polymerization on ZN catalysts, it was suggested that the selective quenching agent ( " CO), interacting only with titanium-polymer bonds [164—166], (QR CO method) be used. The use of carbon monoxide for this purpose is based on the well-known metallorganic chemistry reaction of CO insertion into 8-bond transition metal-aUcyl ... 

Active centers (Cp), functioning in the conditions of 1,2-insertion of propylene into titanium-polymer bmids in the active center... 

Dormant centers (Cj), formed after propylene 2,l-inserti(Mi into titanium-polymer bonds... 

Dormant centers (Cj), do not attach propylene for steric reasmis, but interact with " C0 the same as the active centers Cp. In this case, the QR CO method can define the total number of the centers (Cp + Cj), containing titanium-polymer bmids. 

Surface titanium hydrides (CCTi-H) are highly reactive compounds and can be partially deactivated in side reactions by interaction with components of the catalytic system. As a result of these side reactions, the number of active centers for polymerization in the presence of hydrogen is as a rule lower than the total number of the centers containing titanium-polymer bonds (Cp + Cd) during polymerization without hydrogen (Table 7). In the case of ethylene polymerization, dormant centers (Cd) are not formed. But, for polymerization in the presence of hydrogen,... 

No.25, 1998,p.6533-9 NEW ACRYLIC TITANIUM POLYMERS II. SYNTHESIS AND CHARACTERIZATION OF ORGANOTITANIUM POLYMERS... 

Pb-Agor Pb-Ca, DSA-IrOj Stainless steel or titanium Polymer fabric MnSO, 4wt.%... 

Polymerization of the dichlorosilyl phthalocyanine monomer [57] with resorcinol gave low polymer. Thermal dehydration of the silanediol [58] gave the polysiloxane [61] for which evidence was obtained indicating an appreciable degree of polymerization. Because of the thickness of the phthalocyanine planes, this polymer is felt to contain 180°—O—Si—O—angles. The analogous titanium polymers were intractable and not exceptionally stable (18). 

A series of chelate polymers has been prepared from tetraalkoxy metals and A, jV,A, A -tetrakis(2-hydroxyethyl)diamines (33). Dimethylacetamide is used as the solvent. The reactants that are used to introduce silicon and tin are their tetraethoxy derivatives, whereas tetraisopropoxytitanium was used to incorporate titanium. Polymers of different backbone and metal structure were prepared. From the scant data that are reported about the products, correlations of properties versus structure cannot be made. One point of interest is the much higher melting point that was found for the silicon-containing polymer (R = in [58])as compared to the tin and titanium polymers. 

The storage modulus in the rubber plateau region (above Tg) for MEEP/Ti (1/1) was the highest of all the composites. A factor that would influence the modulus is the higher reactivity of the titanium alkoxide. Thus the titanium sol-gel would be more fully densified under the conditions employed here. At 240, we have found the moduli of the silicon (not shown) and titanium polymer composites to be similar ... 

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