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A series of N, P-ligands bearing carboxyl groups have been synthesized. These have been applied in conjunction with cobalt naphthenate in a facile, economic, and efficient method for the catalytic hydrosilylation of alkenes. In the presence of KOtBu as an additive, the reaction time and activation energy are greatly reduced.

Наведено результати дослідження рідиннофазного окиснення циклогексану у присутності каталітичних систем, які містять нафтенат кобальту та органічні добавки, що впливають на поверхневий натяг. Досліджено дві групи добавок: четвертинні амонієві солі (цетилтриметиламоній бромід, тетрабутиламоній бромід, тетраетиламоній йодид) та естери поліетиленгілколю (поліетиленглікольадипінат, поліетиленгліколь сукцинат, полідіетиленгліколь сукцинат). Показано, що кореляція між впливом органічних добавок на поверхневий натяг та технологічні показники процесу характерна лише для добавок, які мають близьку природу. The article presents the results of a study of the liquid-phase oxidation of cyclohexane in the presence of catalytic systems containing cobalt naphthenate and organic additives that affect on surface tension. Two groups of additives were studied – quaternary ammonium salts (cetyltrimethylammonium bromide, tetrabutylammonium bromide, tetraethylammonium iodide) and polyethyleneglycol ethers (polyethyleneglycol adipate, polyethyleneglycol succinate, polydiethyleneglycol succinate). It is shown that the correlation between the effect of organic additives on surface tension and on technological parameters of the process is characteristic only for additives that are of similar nature.

Purpose – This paper aims to prepare BisGMA (bisphenol-A glycidyldimethacrylate)/jute fibre/fly ash hybrid composites with improved mechanical and corrosive properties. Design/methodology/approach – BisGMA prepolymer was first synthesised using diglycidyl ether of bisphenol-A and methacrylic acid. Then 2-hydroxy ethylacrylate-treated jute fibre and sodium hydroxide-treated fly ash were incorporated in the fabrication of composites using dicumyl peroxide, cobalt naphthenate and N,N-dimethyl aniline as catalyst, accelerator and promoter, respectively. The composition of BisGMA, jute fibre and fly ash was kept constant, whereas treated and untreated jute fibre and fly ash were used alternatively. Findings – Treatment of both jute and fly ash leads to improved mechanical properties of composites. However, treated fabric plays a dominant role compared to treated fly ash as filler. Among all the composites, the one having both treated jute fibre and treated fly ash is the most suitable composite for structural applications. Research limitations/implications – The present investigation has come up with a hybrid composite that can be used for a wide range of applications like low-cost housing and structural projects, structural laminates, etc., as it is both corrosion- and moisture-resistant. It is also the most durable from the mechanical point of view. There is also a scope of using other fillers instead of fly ash to study the changes brought about in the mechanical properties. Originality/value – The above composites have never been fabricated before.

Parinari polyandra Benth seed oil was utilized in the preparation of four sets of alkyd resin (35%, 50%, 60%, and 75% oil formulations) using a two-stage alcoholysis-polyesterification method. The rate of polyesterification was depended on the amount of oil used during synthesis. The properties of the alkyds (drying times, film characteristics, water and acid resistances, and solubility) were evaluated using relevant standards. Inclusion of cobalt naphthenate drier in the alkyds and their exposure to outdoor tempera- ture improved the drying properties. White gloss paints formulated from the alkyds, considering a pigment-volume concentration of 20.67% in the gloss paint formulation compare well with commercial standard. FTIR and 1 H-NMR analysis confirm the alkyd (glycerol- phthalate) structure. V C 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 127: 4610-4616, 2013

Hexagonal cobalt hydroxide (β-Co(OH) 2 ) nanosheets over a size range from 100 nm to 1 μm were synthesized using a very simple hydrothermal route with cobalt naphthenate as the cobalt source. Additionally, hexagonal cobalt oxide (Co 3 O 4 ) nanorings over a size range from 100 nm to 1 μm consisting of cubic nanocrystals were obtained via a hydrothermal method using as-prepared β-Co(OH) 2 nanosheets as the precursors. A probable mechanism of formation of the hexagonal Co 3 O 4 nanorings is proposed on the basis of time-dependent experimental results.

In the present study, the curing behavior of polycardanol prepared by enzymatic oxidative polymerization of thermally treated cashew nut shell liquid, which can be available from naturally renewable resources, was explored in the presence of methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate (Co-Naph). The curing behavior was monitored varying Co-Naph concentration and curing temperature by means of Fourier transform infrared (FT-IR) spectroscopy. The result revealed that the characteristic absorption bands were significantly affected by the given curing condition, resulting mainly from the unsaturated moiety in the polycardanol molecule. The extent of curing of polycardanol strongly depended on curing temperature, showing a typically sigmoidal curve reaching almost 1.0 upon processing at 200°C for 120 min. The thermal curing conditions for preparing polycardanol with an optimal state of cure were provided in the work. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Jatropha curcas Linnaeus (JCL) seed oil was utilized in the preparation of four sets of alkyd resin (35%, 50%, 60% and 75% oil formulations) using a two-stage alcoholysis–polyesterification method. The rates of polyesterification depended on the amount of oil used during synthesis. The properties of the alkyds were evaluated. The range of solidification times was between 278 and 442 s; also the range of film thickness was between 0.014 and 0.08 mm, and the alkyds were readily soluble in turpentine, xylene and butanol. Inclusion of cobalt naphthenate as drier and outdoor temperature (37 °C ± 2) improved the drying properties of all the alkyds. The colours of white gloss paints formulated from the alkyds, considering a pigment-volume concentration of 20.67% in the gloss paint formulation, compared well with that of a paint formulated using a commercial alkyd sample. 1H NMR analysis confirms the expected structure of the alkyds.

Taking modified unsaturated polyester as the matrix resin, methyl ethyl ketone peroxide (MEKPO) and cobalt naphthenate as the redox system, and TiO2, SiO2 and hollow glass beads as the functional fillers, a thermosetting heat-reflective coating with good temperature-reduction effects and wearing resistance, which can be quickly solidified under the room temperature has been produced. In accordance to the research, the amount of solidifying agent and accelerant has great bearing on the gelation time of the coating, and the optimum usage for this system of which will be: 2.5% cobalt naphthenate and 2% MEKPO or 3% cobalt naphthenate and 2% MEKPO; as the increase of the fillers, the temperature reduction effects will be quickly enhanced at the beginning, and then tend to be stable, when the quantity of the fillers is less than 10%, the covering effect of the coating is not obvious, when it is more than 20%, construction difficulties will occur because of the excessive viscosity of the coating. Fillers of 14% with low viscosity and better temperature reduction effect is recommended; as the ratio of TiO2 to SiO2 decreases, the temperature reduction effect of the coating is weakened while the abrasion resistance strengthened and the glossiness reduced; the addition of hollow glass bead can better realize the temperature reduction of the coating, however the glossiness of which will be increased; Colored pigments have slightly negative impact on the temperature reduction of coating. The prepared coating has good abrasion resistance, and can reduce the pavement temperature by almost 10 during hot seasons when it is applied on pavement.

Three mixed liquids, Styrene, Methylmethacrylate and Vinyl acetate were used to soak poplar veneer to obtain strengthen poplar veneers. The optimal molar ratio was fixed on 1:2:1.Soaking and polymerization technology were obtained as pressure 0.4Mpa, packing time 60 minutes, polymerization temperature 80°C, polymerization time 6 hours, cobalt naphthenate 2%, zinc chloride 6%, and azobisisobutyronitrile 3%. The impact of high temperature on the conversion was significant in the chosen level, other factors on the conversion rate was not significant.

Two surveys, one in winter the other in summer time, examined the skin problems of the entire manual workers (N=148) from 11 small-to-medium sized fiber-glass reinforced plastics (FRP) factories located in Kyushu, Japan. The workers were exposed to unsaturated polyester resin, including styrene and auxiliary agents such as cobalt naphthenate, hardeners such as methyl ethyl ketone peroxides, glass fiber and dust including shortened glass fiber and plastic particles. Eighty- seven workers (58.8%) reported having skin problems (mainly itching or dermatitis) since they started to work in FRP manufacturing and 25 workers had consulted a physician because of their skin problems; one worker was forced to take sick leave because of his severe dermatitis. History of allergic diseases and shorter occupational period (duration of employment) in a FRP factory were associated with greater probability of having a history of work-related skin symptoms. Workers in factories where dust-generating and lamination sites were located in different buildings were significantly less likely to have a history of skin problems than those in factories where the two sites were located in the same building. Of the 67 workers examined in both seasons closed to double the prevalence of dermatitis was found in summer (23.3%) than winter (13.4%).

Summary Polyglycerol (PG), an agricultural by-product of diester industry, was reacted with maleic anhydride (MA) to give heat curable compounds which are useful for impregnating wood to improve biological resistance, dimensional stability and strength. The relationships between reaction conditions of polyglycerol/maleic anhydride (PG/MA) adduct treatment and performance of treated solid wood were investigated. Conditions recommended for producing PG/MA treated wood durable for a long time are vacuum/pressure impregnation of aqueous solutions of PG/MA adduct (30%) in the presence of 2-butanone peroxide (2%) and cobalt naphthenate (2%).

The SBR-NR adhesion to the zinc plated steel cords were studied and the effects of different kinds of accelerators, sulfur dosage and cobalt-naphthenate content on the adhesion have been investigated. The experimental results before and after water aging and heat aging were shown by measurement of peel strength and rubber coverages. The optimum sulfur content in blend was about 3.5phr for the Zn-rubber adherends, while using MBTS and BBS. The wet corrosion of the adherends was promoted by extra addition of cobalt-naphthenate. However, by using TMTD, the peel strength and rubber coverages after aging test were higher than values before aging test. It can be caused due to the suitable interface layer formed during aging test. It was found that the good adhesion were obtained when using nickel naphthenate salt. Furthermore, with addition of nickel naphthenate, the Zn-rubber adherends showed more excellent wet corrosion resistence than that of cobalt naphthenate.

The effect of the addition of methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate (CoNaph) on the mechanical behavior of epoxy vinyl ester resin (EVER) laminates has been investigated by using a factorial experimental design, in which the MEKP and NaphCo contents were varied. Previous results showed that there is an interaction effect between the process variables analysed on the mechanical properties evaluated. It was also observed that the MEKP/CoNaph ratio affected the tensile behavior of the EVER/glass fiber composites.

The retardation of cobalt driers was investigated using a commercial alkyd. The onset of curing and crosslink density of the alkyd was used to evaluate four cobalt complexes, Co(acac)2, Co(acac)3, Co(OH)2, and Co(NH3)6Cl3. The catalytic activity of these complexes were compared to cobalt naphthenate. Differential scanning calorimetry and dynamic mechanical thermal analysis data were used to determine acceleration or retardation of the autoxidation drying mechanism. The Co(acac)2 accelerates the process in comparison to Cobalt(II) naphthenate, whereas the three other complexes seem to retard the process.

Cyclisation of maleamic acids with acetic anhydride in dimethylacetamide (DMA) at ca. 75 °C, with or without added cobalt naphthenate, gives predominantly maleimides when the parent maleic anhydride is unsubstituted. However, when the maleic anhydride has either one or two methyl substituents, the products are 95% maleisoimides (5-imino-2,5-dihydrofuran-2-ones). In contrast all maleamic acids investigated, regardless of the extent of substitution, give exclusively maleimides when heated in acetic acid under reflux. Isoimide formation in the Ac2O–DMA–cobalt naphthenate procedure appears to arise from kinetic control, since the isoimide preference was reduced at higher reaction temperature. The preferred Z-stereochemistry of the isoimide 3 is confirmed by X-ray crystallography.

Polymer concrete composites have been made from orthophthalate-type unsaturated polyester resin, methyl ethyl ketone peroxide as initiator, cobalt naphthenate as accelerator and desert sand as filler. Composites preferred using resin (10-25 per cent), initiator (4 per cent) and accelerator (2 per cent) with representative desert sand samples of different particle sizes (0.2-0.02 mm, 2-0.2 mm and 4-2 mm) as filler recorded unconfined compression strength ranging from 4 to 442 kg/cm/sup 2/ after curing at 50 degree centigrade in an oven for 0.5-24 h. Using coarse and fine sand samples with 10 and 15 per cent resin systems the maximum strength of 391 and 326 kg/cm/sup 2/ respectively was attained after 2 h of curing at 50 degree centigrade. The fast setting resin system with strength in this range is quite adequate for the construction of chemically stabilised surfaces, which withstand trafficability of vehicles, operation of helicopters and aircraft's requiring a maximum strength up to 275 kg/cm/sup 2/. These composites may prove useful for rapid repair of roads, helipads and runways damaged during operational activities. A mathematical model has been developed for predicting resin percentage needed for obtaining composite material of requisite strength. The observed and model predicted values have been found to show close agreement.

The bonding of several black-filled natural rubber vulcanizates to brass-plated steel cord was investigated using the TCAT pullout geometry. Compositions using either cobalt naphthenate or an HR bonding system (hexamethoxymethyl melamine plus RFR) had higher pullout forces than a control without these agents. However, the highest pullout forces, both initially and especially after aging, were obtained when the cobalt and HR additives were used together. Results from ATR spectra show that the RFR migrates to the brass surface, and it is proposed that this provides a barrier to attack by moisture of the brass-rubber interfacial region. In support of this idea, moisture uptake is reduced for compositions containing the HR bonding system. Moreover, in the presence of cobalt naphthenate, sulfidation of brass gives a surface topography of substantially higher surface area than seen if this agent is absent. This is expected to promote interlocking between the rubber and the outwardly growing sulfide layer. Finally, the HR resin is able to remove both zinc and cobalt from squalene solution. It is hypothesized that cobalt and the HR resin each have beneficial effects as noted previously, but the subsequent removal of cobalt from the rubber phase by complexing with the HR resin may prevent cobalt, a well-known oxidation catalyst, from promoting degradation of the rubber during aging.

β–Co(OH)2 hexagonal nanoplates with a size range from 300 nm to 3 μm have been synthesised successfully by a template and surfactant–free solvothermal route in a very simple system composed only of water, LiOH and cobalt naphthenate in xylene solution. This method is high–yield, simple and environmentally benign. The as–obtained Co(OH)2 hexagonal nanoplates can be easily converted into CoO octahedrons with the size of 15 μm by increasing reaction temperature.

The compounds were prepared according to the following procedure. The polyether resin was dissolved in an equal quantity (by weight) of styrene. After mixing the components carefully, an initiator of setting (methylethylketone peroxide) was introduced into the solution (I part by weight) and after carrying out additional mixing, the same quantity of the accelerator (cobalt naphthenate) was added to the mixture.

Implications for cord adhesion from this study are as follows: 1) In the low-adhesion compounds containing low cobalt naphthenate and sulfur levels, adhesion increases with decreasing cobalt naphthenate:sulfur ratio, at a given amount of cobalt naphthenate. 2) Under mild curing condition (160°C, 20 min), high-adhesion compounds, containing high cobalt naphthenate and sulfur level, do not show a decrease in adhesion, even if the cobalt naphthenate:sulfur ratio is increased. However, after overcuring (160°C, 60 min), adhesion loss is encountered with increasing cobalt naphthenate:sulfur ratios, at a given cobalt naphthenate level. 3) A high level of unaged adhesion can be obtained if products with a combination of low cobalt and high sulfur content are formed on the brass surface. This condition obtains if the compound contains large amounts of cobalt salt and sulfur and a small ratio of cobalt salt to sulfur. 4) With a high-adhesion compound, the unaged adhesion is rather insensitive to the amount of accelerator. 5) After humidity aging, the adhesion of a high-adhesion compound varies depending upon the amounts of sulfur and accelerator. Compounds containing small amounts of sulfur show a decrease in adhesion with increasing amounts of the accelerator. However, compounds containing large amounts of sulfur maintain high adhesion, even with large amounts of accelerator. 6) For unaged adhesion, only a slight influence is observed by varying the amount of stearic acid. After humidity aging, however, compounds containing larger amounts of stearic acid show a decrease in adhesion, especially in the presence of large amounts of cobalt naphthenate. 7) Compounds which promote the formation of ZnO on the surface during bonding maintain a high adhesion level after humidity aging. This is similar to the effect of using a cord plated with brass containing a higher zinc level.

EPDM stocks containing 5-norbornene-2,3-dicarboxylic anhydride and cobalt naphthenate, when sulfur vulcanized onto RFL-treated fabrics, show a significant increase in peel adhesion properties. EPDM's containing ENB, as the termonomer, have been found to give the best results. The accelerator is an important part of the total adhesion system. Only the slower curing types are applicable, such as sulfenamides and thiazoles. Both soluble and insoluble sulfur yield equivalent adhesion properties, but the insoluble form has the advantage of producing a higher modulus stock. This adhesion system is applicable to only RFL-treated fabrics in which the latex is a styrene-butadiene-vinyl pyridine type. Reduction of compounded stock cost is possible by increased filler loadings or by the use of a skim coat technique, while still providing improved adhesion properties. Variations in both carbon black and oil levels produce corresponding changes in modulus development and curing time. These properties can be used to predict adhesion results.

The polymerization of hexamethylenediisocyanate (HDI) by Co-naphthenate was studied to establish conditions for fast exothermic reaction required for foam polymerization. Addition of an optimal concentration of DMSO (or DMF) activated the catalyst and lowered the induction period. Better control of the reaction was obtained in the presence of tributyltin oxide which showed a synergistic effect with the catalyst, and on using prepolymers of HDI. The resulting HDI foams were friable and their flammability was lower than that of aromatic polyisocyanurates.

Initiation of oxidation and polymerization of OEAs by 1,1′-bis-hydroperoxydicyclohexylperoxide and by the products of oxidation (polymeric peroxides and hydroperoxides) in the presence of cobalt naphthenate, to degrees of conversion close to zero, and in partially hardened OEAs (C = 30–50%), has been investigated. It is shown that the rate of initiation decreases as the degree of conversion increases. It was found that the polymeric hydroperoxides, in contrast to polymeric peroxides, are efficient initiators of oxidation and polymerization of OEAs in the presence of cobalt naphthenate.

Nine photocrosslinkable unsaturated polyesters containing pendent chalconyl and cinnamylidenemalonyl moieties have been synthesized by a route involving no water elimination. The resins are insolubilized by visible and UV irradiation. They can also be cured with styrene, MEK peroxide, and cobalt naphthenate. A study of the photoreactions reveals that the resins containing 4′-chalconyl groups crosslink and isomerize simultaneously, whereas those containing 4-chalconyl groups undergo crosslinking only, due to the steric suppression of isomerization. Photoinsolubility is also achieved by introducing the cinnamylidenemalonyl group into the resin structure. It is found that the resins containing both the chalconyl and cinnamylidenemalonyl groups in the repeat units do not exhibit any pronounced photofastness.

C4 olifines were continously hydroformylated in the presences of cobalt naphthenate as catalyst and Pd-zeolit as promoter like the preceding reports.The reaction temperature was necesary to keep over 140°C, presumably: owing to the fact that the charge stock contained much isobuten of smaller reaction velocityAddition of Pd-zeolite as promoter was equally useful as in theanot-her experiments.The content of high boiling points fraction in the product was about 15%, the yield of amylalcohol being 80-85%.

Cobalt naphthenate has been employed in adhesives for joining metals and rubber e.g. steel cord tyres and conveyor belts, to promote adhesion, and in elastomeric compounds for adhesion to brass‐ plated metals. It has also been employed in hardeners for epoxy resin adhesives, and as a reducing activator in the manufacture of anaerobically‐cured adhesive systems.