Typical conditions

For typical conditions in the chemical industry, the effect of pressure on liquid-liquid equilibria is negligible and therefore in this monograph pressure is not considered as a variable in Equation (2). 

Under typical conditions and flow rates up to 50 meters/second the accuracy has been experienced to be considerably below 0.5%. 

Ultrasonic Welding. Ultrasonic welding has been appHed to Tefzel with weld strength up to 80% of the strength of the base resin. Typical conditions include a contact pressure of 172 kPa (25 psi) and 1—2 s cycle time. The two basic designs, the shear and butt joints, employ a small initial contact area to concentrate and direct the high frequency vibrational energy. 

The majority of thermal polymerizations are carried out as a batch process, which requires a heat-up and a cool down stage. Typical conditions are 250—300°C for 0.5—4 h in an oxygen-free atmosphere (typically nitrogen) at approximately 1.4 MPa (200 psi). A continuous thermal polymerization has been reported which utilizes a tubular flow reactor having three temperature zones and recycle capabiHty (62). The advantages of this process are reduced residence time, increased production, and improved molecular weight control. Molecular weight may be controlled with temperature, residence time, feed composition, and polymerizate recycle. 

Solvent Process. In the solvent process, or solvent cook, water formed from the reaction is removed from the reactor as an a2eotropic mixture with an added solvent, typically xylene. Usually between 3 to 10 wt % of the solvent, based on the total charge, is added at the beginning of the esterification step. The mixed vapor passes through a condenser. The condensed water and solvent have low solubiUty in each other and phase separation is allowed to occur in an automatic decanter. The water is removed, usually to a measuring vessel. The amount of water collected can be monitored as one of the indicators of the extent of the reaction. The solvent is continuously returned to the reactor to be recycled. Typical equipment for this process is shown in Figure 2. The reactor temperature is modulated by the amount and type of refluxing solvent. Typical conditions are ... 

Alkoxylation. Ethoxylation of toluenediamines proceeds easily. Typical conditions are 90 to 120°C at pressures up to 500 kPa (72.5 psi) using a basic catalyst, eg, potassium hydroxide (13). 

Benzoic Acid. Ben2oic acid is manufactured from toluene by oxidation in the liquid phase using air and a cobalt catalyst. Typical conditions are 308—790 kPa (30—100 psi) and 130—160°C. The cmde product is purified by distillation, crystallization, or both. Yields are generally >90 mol%, and product purity is generally >99%. Kalama Chemical Company, the largest producer, converts about half of its production to phenol, but most producers consider the most economic process for phenol to be peroxidation of cumene. Other uses of benzoic acid are for the manufacture of benzoyl chloride, of plasticizers such as butyl benzoate, and of sodium benzoate for use in preservatives. In Italy, Snia Viscosa uses benzoic acid as raw material for the production of caprolactam, and subsequendy nylon-6, by the sequence shown below. 

Benzal chloride is hydrolyzed to benzaldehyde under both acid and alkaline conditions. Typical conditions include reaction with steam in the presence of ferric chloride or a zinc phosphate catalyst (22) and reaction at 100°C with water containing an organic amine (23). Cinnamic acid in low yield is formed by heating benzal chloride and potassium acetate with an amine as catalyst (24). 

The electrofluorinated organics of principal industrial importance are perfluorooctanoic acid [335-67-1/, CE2(CE2)gCOOH, and perfluorooctanesulfonic acid [1763-23-1/, CE2(CE2)yS02H. Typical conditions for preparation of the latter compound involve batch electrolysis of a 10 wt... 

Gas-liquid chromatography has been widely used for the identification of reaction mixtures and for the separation of heterocycles. Some typical conditions are shown in Table 34. 

Figure 5.5. Deformation-mechanism maps for MAR-M200 superalloy with (a) 100 pm and (b) 10 mm grain size. The rectangular box shows typical conditions of operation of a turbine blade, (after Frost and Ashby 1982). (c) A barchart showing the range of values of expansion coefficient for generic materials classes. The range for all materials spans a factor of almost. 3000 that for a class spans, typically, a factor of 20 (after Ashby 1998).

MgBr2-Et20, Mc2S, CH2CI2, it, 75-96% yield. " The failure of this substrate to undergo cleavage with the typical conditions was attributed to the presence of the 1,3-diene. Acetonides and TBDMS ethers were found to be stable. 

Typical conditions would be to pass a mixture of SO2 and air over Pt gauze or more commonly a V20,s/K20 contact catalyst. supported on Kiesel-guhr or zeolite. 

Imines with an electron-withdrawing group at the nitrogen atom are excellent acceptors for the acetate (1) or the carbonate (13) [36]. Thus, N-tosylimines (84) gave very good yields of pyrrolidines (85) under typical conditions. The strained cyclic imine (86) and a,/ -unsaturated imine (87) both participated smoothly in the cydoadditions. The hindered nitrimine (88) also reacts well with (1) (but not with 13) to produce the pyrrolidine (89) with a 17 1 diastereoselectivity. However, the unhindered nitrimines from cyclohexanone and 2-nonanone failed to react presumably due to enolization (Scheme 2.24). 

A variety of catalysts, solvents and amines as base can be employed for the Sonogashira reaction. Typical conditions are, e.g. tetrakis(triphenylphosphine)palladium(0)... 

Nucleate vaporization rates usually run 15-40% (but can be as low as 2-10%) per pass through the unit for organic materials, averaging about 25-28% for many typical conditions. Aqueous solutions range from a low of 5% to 25-30%. 

Typical conditions for the disproportionation reaction are 450-530°C and 20 atmospheres. A mixture of C0O-M0O3 on aluminosilicates/alumina catalysts can he used. Conversions of approximately 40% are normally used to avoid more side reactions and faster catalyst deactivation. The equilihrium constants for this reaction are not significantly changed hy shifting from liquid to vapor phase or hy large temperature changes. 

The coupling reaction of zinc(II) (3- or)8-monobromodeuteroporphyrin dimethyl ester (ID with 1,4-divinylbenzene under the typical conditions of the Heck reaction results in the formation of dimeric porphyrin 12 linked via a divinylbenzene moiety. Use of 1,3,5-trivinyl-benzene in the same reaction makes the trisadduct available."5... 

Some of the typical conditions of polycondensations used for aliphatic and aromatic monomers are not suitable for furan derivatives, e.g., the melt polycondensation of 2,5-furan dicarboxylic acid chloride with 2,5-b/s(hydroxymethyl) furan at about 80 °C only yields a black insoluble product5. The hydrochloric acid liberated in the reaction is clearly responsible for the charring of the furanic diol which like its simpler homologue furfuryl alcohol, resinifies rapidly in acidic media (see below). 

Major advantages of this method over other trapping techniques are that typical conditions for solution/bulk polymerization can be employed and that a very wide range of initiating systems can be examined. The application of the... 

The corresponding half-imidic esters have also been used to afford 3-amino-2(17/)-quinoxalinones. The following examples illustrate typical conditions and yields. 

The low-pressure chemical vapor deposition of silicon nitride on silicon involves two gaseous reactants dichlorosilane and ammonia. The following reactions are believed to be important under typical conditions of P = 1 torr and T= 1000 1200 K ... 

The Vinyloop process is based on the selective dissolution of PVC used in composites applications like cable insulation, flooring, tarpaulins, blisters, etc. After removal of insoluble parts like metals, rubber or other polymers, the PVC is reprecipitated with all additives by introduction of a non-solvent component whieh will form with the seleetive solvent an azeotropie mixture. By using typical conditions, the process is able to reeover a pure PVC eompound powder ready for use without any additional treatment like melt filtration or a new pelletisation (speeific characteristics of the powder are average diameter of 400 microns and bulk density above 600 kg/ eub.m). All the solvents used are eompletely reeyeled and reused. PVC compounds recovered in the Vinyloop process can be reused in a closed-loop recycling scheme... 

Other cyclizations at phosphorus have been observed when certain phosphinates were used in the acid-catalyzed Mannich reaction. As observed previously with various phosphonous acid derivatives, reaction of aliphatic phosphinic acids with primary amines favored the formation of 2 1 adducts (73). Thus, glycine and other a-amino acids reacted under the typical conditions with excess formaldehyde and alkyl phosphonous acids to give the bis-phosphinylmethyl adducts 125. 

Larock has developed a new catalyst system for the Pd-catalyzed cyclization of olefinic tosylamides. Whereas typical conditions require either stoichiometric amounts of Pd(II) salts or catalytic amounts of Pd(II) in the presence of benzoquinone as a reoxidant, the new catalyst system utilizes catalytic Pd(OAc)2 under an atmosphere of O2 in DMSO with no additional reoxidant <96JOC3584>. Although o-vinylic tosylamides 76 can be cyclized to Af-tosylindoles 77 using this catalyst system, PdCla/benzoquinone is more effective for such cyclizations. Interestingly, in the case of o-allylic tosylanilides, the cyclization can be modulated to afford either dihydroindole or dihydroquinoline products. In a related approach involving a common 7i-aUyl Pd-intermediate, 2-iodoanilines were coupled with vinylic cyclopropanes or cyclobutanes in the presence of a Pd catalyst to afford dihydroindoles <96T2743>. 

An explanation of why the normal distribution will have to be used as a model, even though the adherence to ND (or other forms) cannot be demonstrated under typical conditions,... 

Examples of typical conditions employed in the sterilization of pharmaceutical and medical products... 

Typical conditions in a process using H2SO4 as the catalyst are 5-10 °C, 2-5 bar, iso-butane olefin ratios of 10, and a residence time in the reactor of 20-30 min. The catalyst consumption rate is high (about 100 kg of acid per ton of alkylate prod-... 

---