Bonding time/temperature

Bonding time temperature. The temperature required for curing in a reasonable time and the relation between temperature and time of cure varies with the formulations used. 

Smooth surfaces are normally estabflshed by calendering, a process which subjects the fabric at the nip point(s) of two or more roUs to the influence of controlled time, temperature, and pressure. When calendering is used as a thermal-bonding process, the roUs are of the same dimension and composition and are independently driven. However, when calendering is used as a fabric finishing operation, the roUs are frequently of different dimensions and composition and are not always independently driven. 

A more recent process, the P2 etch [60], which uses ferric sulfate as an oxidizer in place of sodium dichromate avoids the use of toxic chromates, but still provides a similar oxide surface morphology (Fig. 15) allowing a mechanically interlocked interface and strong bonding [9]. The P2 treatment has wide process parameter windows over a broad range of time-temperature-solution concentration conditions and mechanical testing confirms that P2-prepared surfaces are, at a minimum, equivalent to FPL-prepared specimens and only slightly inferior to PAA-prepared surfaces [61]. 

Products isolated from the thermal fragmentation of A-arylbenzamide oximes and A-arylbenzamide O-phenylsulfonyl oximes have been accounted for by invoking a free-radical mechanism which is initiated by the preferential homolysis of the N-O bond." Time-resolved IR spectroscopy has revealed that photolysis of A, A -diphenyl-l,5-dihydroxy-9,10-anthraquinone diimine affords acridine-condensed aromatic products via excited-state intramolecular proton transfer." The absolute and relative rates of thermal rearrangements of substituted benzyl isocyanides have been measured,and it has been found that the relative rates are independent of temperature and exhibit excellent Hammett correlations. Thionitrosoarene (25), thought to be generated by desulfurization of the stable A-thiosulfinylaniline (24), has been established" " as an intermediate in the formation of 3,3a-dihydro-2,l-benzisothiazole (26) from o-alkylthionitrosoarene (24). 

Zou S, Schonherr H, Vancso GJ. Force spectroscopy of quadmple H-bonded dimers by AFM dynamic bond rupture and molecular time-temperature superposition. J Am Chem Soc 2005b 127 11230-11231. 

Chow and coworkers have studied the thermal inactivation of white spruce veneer in detail (61, 62, 63). They were not able to correlate bond quality to the concentration of fatty acids on the veneer surface. They found instead that surface inactivation was a function of time, temperature, and atmosphere. Even extractive-free veneer could be inactivated the presence of extractives did accelerate the inactivation. The infrared spectra of the veneer... 

The described conditions alkylate cysteine residues almost quantitatively, even for defensins, which contain three disulfide bonds. Higher temperatures (>37°C) and longer reaction times (> 1 h) do not further increase the cysteine alkylation but may produce further byproducts, such as carboxymethyllysine (CML). 

The phenoxy resins can form strong bonds to metals in seconds at temperatures from 315 to 340°C. At these bonding conditions, a tensile lap shear strength of 3500 to 4000 psi can be obtained on aluminum. The same bond can be made in 2 to 3 min at 260°C and in 30 min at 190°C due to the thermoplastic phenoxy s time-temperature creep characteristics and relatively low softening temperature (100°C).8... 

If a cure of 60 min at 150°C is recommended, this does not mean that the assembly should be simply placed in a 150°C over for 60 min. The temperature is to be measured at the adhesive bond line. A large part will act as a heat sink and may require substantial time for the adhesive in the bond line to reach the necessary temperature. In this example, total oven time would be 60 min in addition to whatever time is required to bring the adhesive up to 150°C. Bond line temperatures are best measured by thermocouples placed very close to the adhesive. In some cases, it may be desirable to place the thermocouple in the adhesive joint for the first few assemblies being cured. 

As antiscuff, anti-wear properties of additives depend on the covalent-bonded sulfur contents, the selection of optimum conditions to effect sulfuring processes has been set with introducing the greatest amount possible of covalent sulfur. For this purpose functionalizing of diene and olefin hydrocarbons was conducted on a wide time-temperature mode. Considering that the temperature of boiling pipeiylene fraction low (42-44°C), sulfuring was carried out in a constantly temperature-controlled autoclave in the presence of the catalyst cobalt phthalocyanine [3], in the medium of non-polar solvents (for example, heptane). Under... 

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