Additives and Catalysts

As of this writing (1997), researchers are exploring combinations of acids, additives, and catalysts to achieve a suitable economic finish. However, commercial appHcation of these finishes would require costs akin to that of DMDHEU as well as compliance with formaldehyde release levels by consumers, regulators, and the textile industry. Another possible impetus could be marketing considerations. Nevertheless, this work has sparked intense effort in the use of cross-linkers containing ester cross-links and has broadened the scope of cross-linker research. 

Addition of Achiral Enolates to Achiral Carbonyl Compounds in the Presence of Chiral Additives and Catalysts... 

Oda, T., Kato, T., Takahashi, T. et al. (1998) Nitric oxide decomposition in air by using nonthermal plasma processing with additives and catalyst, IEEE Trans. Ind. Appl. 34, 268-72. 

Glycolysis is also conducted to create polyols for unsaturated polyester usage. The PET can be dissolved in DEG to create polyols with ether linkages [30], The reaction can be carried out with propylene glycol [31] or by reacting with an unsaturated dibasic acid [32] and needed additives and catalysts [33],... 

Specialties 55% ( 990 billion) Additives and catalysts Biocides Dyestuffs and pigments Electronic chemicals Flavors and fragrances Food and feed additives Household and personal care Life science products Specialty polymers / Pharmaceuticals Veterinary drugs Agrochemicals... 

First, the stability of the formulation containing resin, additives, and catalysts is judged. Second, the reactivity of the dip has to be in a certain range. Third, on ready-made laminates (either hpl or plywood based) the surface tension of water droplets is determined. In this test it can easily be seen that paper with hydrophobic additives is more repellent toward liquids than ordinary paper (Fig. 2). 

Decomposition and by-products—The reaction temperature and time should be decreased until minimal or no decomposition or by-product is seen. If the formation of by-product or decomposition is stiU prominent at the lowest temperature and time achievable, then reaction conditions need to be reviewed and optimized in terms of combination of solvents, additives, and catalysts. 

Some other applications of polarography to the determination of polymer additives and catalyst remnants are reviewed in Table 2.14. 

Thiazinediones 513 are constmcted in 78% yield when ketenes react with thioacyl isocyanates, as in the reaction of thiobenzoyl isocyanate with diphenylketene (Scheme 168) (1972CB3322). These reactions are performed in ether or aromatic solvents in the absence of additives and catalysts. The isolation of azetidinedione as by-products has been reported. 

Raw materials for polyurethane preparation are isocyanates, polyols (sometimes polyamines) and catalysts. Polyols are fairly harmless substances, but the polyol component may contain hazardous additives and catalysts. Amine chain extenders and catalysts present usual hazard like all amines, i.e., they are often carcinogenic. This is especially true of MOCA. Metal catalysts are also very toxic and careful handling is necessary. 

Nguyen TV, Wu JCS (2008) Photoreduction of CO2 in an optical fibres photo-bioreator effects of metal addition and catalyst carrier. Appl Cat A 335 112-120... 

The cement content in deflocculated castables is low. Hence, the amount of heat they produce during setting is low. The time of installation can therefore be limited to 24 h. There are special ULCC castables, which are installed in blast furnace trough systems. They contain metallic additives and catalysts. Because of these, an intensive exothermal reaction takes place after the addition of water. Hydrogen is produced out of this reaction. It creates capillaries as it escapes from the structure. These capillaries help in the self-drying process because they increase the surface area from which heat is remov. Because of the fast reaction and drying, the furnace can be put into operation in a short time. 

Deflocculated castables contain lower amormts of cement, which produce a slight amount of heat. From this point of view, everything stated above can be limited to 24 hr in most cases. For ULCC- and NCC-type castables, the supply of heat will most likely be required to obtain sufficient green strength. Consequently, subsequent treatment of the castable will not be required in the sense described above. Special ULCC castables, which are installed in blast furnace trough systems, contain metallic additives and catalysts. These effect... 

The concept of unsaturated polyesters (international abbreviation UP) which can be cured and hardened by heating with sources of radicals was developed by C. Ellis in the 1930s [1-3], and the first patent application was submitted in 1936 Ellis also discovered that dilution of the unsaturated polyesters with vinyl monomers, such as styrene (most widely used) or vinyl acetate is favorable for most applications. The dilution reduces the viscosity. Eases the dissolution of additives and catalysts and lowers the costs. The most frequently used catalysts for the curing process are peroxides. The variation of their structure allows for optimization of the cure. The most important application of UPs are ... 

---