Aging stability

Two aspects of oxide hydration are generally considered. One is hydration during the growth of the oxide. The other is the interaction with water of aging oxides immersed therein. This is important for improving aging stability of oxides and their corrosion resistance.209... 

In the nineteenth century dammar, a soft resin derived from trees of southern Asia was introduced in Europe and used for making colourless varnish. Mixed with oil of turpentine it has become the preferred varnish for oil painting, due to its superior optical properties and better ageing stability than the other natural resins. 

In principle any diol/triol mixture which reacts with a diisocyanate will yield a network. However, to be useful as propellant binder, additional requirements must be met. The most important are low cure shrinkage, low reaction exotherm, rubbery characteristics down to arctic temperatures, good aging stability, and ease of handling during propellant manufacture. 

Another means to achieve better bonding is to increase the contacting surface area. Finally, the aging stability of liners has to be at least as good as that of the propellants with which it is used. 

It differs from catocene and other ferrocene derivatives in respect of safety and ageing stability, that is, it is much safer and gives better ageing stability. 

These basic materials eventually are converted to their neutral salts by use of some alkaline material, such as sodium hydroxide. Additional, minor ingredients are added, e.g, sodium silicate or magnesium sulfate, to control alkalinity, odor, and aging stability. 

A number of factors govern the composition of vinegar the nature of the raw material, the substances added to promote alcoholic fermentation and the growth and activity of Acetobacter, the procedure used for the acetification, and finally the aging, stabilization, and bottling operations. 

Viscosity aging behavior has been shown to be dependent on exposed resin surface area and agglomerate fusion.Higher dryer temperatures will decrease the former and increase the latter, resulting in better viscosity aging stability. 

PREDICTION OF PHOTO AGEING STABILITY OF PLASTICISED PVC FILMS CONTAINING UV STABILISERS... 

TABLE 2. Thermal aging stability and storage modulus analysis of laminates coated with selected experimental agents using PMMA or PC as the coating substrate. 

The earliest zeolite catalysts used in alkylation date back to the 1960s with rare earth-stabilized X and Y - REX and REY [11,12]. Historically, the three major catalyst attributes - activity, selectivity and aging stability - could not be achieved. Quite often, stability was the key limitation. 

Levantovskaya, Ageing and stabilization of polymides. Ageing stabilization of polymers . Moscow, ""Science (1964), 197 (in Russian). 

The polyolefinic hotmelt adhesives are characterized by aging stability, i.e., the laws of adhesion and flexibility and the appearance of yellowing are not as pronounced as in the TPEs. 

Aviation oils The bulk of aviation lubricant demand is for both military and civilian gas turbine lubricants. Hydrocarbon oils cannot meet the requirements placed on jet engine oils, primarily lubrication, oxidation and ageing stability. Type 1, the first generation of oils were diesters but over the last 30 years have lost ground to the more expensive polyol esters. Type 2. Some diesters are still used in less demanding applications such as for small private aircraft and turbo-prop engines. Type 2 aviation gas turbine lubricants are produced to a viscosity of 5 cSt at lOO C but for some military applications where low-temperature operability is vital, this is reduced to 3 cSt. 

In contrast to the young adhesives on synthetic bases, adhesives deriving from natural products have partly been known for millennia. The essential differences compared to reactive adhesives are the partially poor ageing stabilities in humid atmosphere as well as the low bonding strengths. They are not used for highly strained bonded joints of metals, plastics, glasses and similar. However, they record... 

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