Stabilizer blooming

The methods used to correlate suspensibility may be used with other response variables — such as biological activity, stability, or yield value — that are important in the development of pesticides. Also, formulations of greater complexity, which have more components, can be studied with the same correlational techniques. There are, however, many important response variables that are qualitative or semiquantitative and are not usually estimated with the precision necessary for reliable regression analysis. These include, freeze-thaw stability, bloom, compatibility, and... 

In amorphous systems, e.g. in rubbers, a better solubility of stabilizers and a more uniform distribution than in polyolefins can be reached. The equilibrium stabilizer concentration should not exceed the saturation state to prevent stabilizer blooming after 1 year storage at ambient temperature. Complications may arise with insoluble stabilizers, as with JV,h/ -diaryl-l,4-phenylenediamine in rubbers [16]. The limited solubility does not allow a sufficient antiozonant protection to be achieved. 

In linear low density polyethylene (LLDPE) also, the polymeric HALS-II and HALS-III show much better performance than other commercial light stabilizers. Blooming is observed with low molecular weight HALS-I, similar to that found with LDPE. 

Used in combination with other accelerators, the dithiophosphates reduce the risk of bloom and the formation of nitrosamines. Generally reversion stability is improved. The copper dithiophosphate will cause discolouration and contact staining. 

Their solvent stability is poor, it approaches that of the above-mentioned yellows (Sec. 2.3.3). Migration characteristics, i.e., fastness to bleeding and blooming, are consequently inferior, although the pigments are generally resistant to alkali and acid. 

Light. Ultraviolet (uv) light promotes free-radical oxidation at the mbber surface which produces discoloration and a brittle film of oxidized mbber (35). This skin cracks in random directions to form a pattern called crazing, which can be prevented by the addition of carbon black fillers or uv stabilizers. Black stocks are more resistant to uv light than are gum or light-colored stocks. Nonblack compounds require larger quantities of nonstaining antioxidants which should bloom to the surface as the surface uv stabilizers deplete. 

The electron patterns are the primal shapes of nature. Fundamentally, all of nature s shapes can be traced to such patterns. Even the properties of living substances are based on them—in particular, the properties of the molecules that carry the hereditary code. In the final scientific analysis, the stability of electron wave patterns causes the same flowers to bloom every spring and makes children similar to their parents. 

During the 1970-1980s, a mixture of ammonium fluoroborate and antimony oxide was offered on the market. This mixture was used in polypropylene with dechlorane (a chlorine source) to achieve V-0. In the absence of added halogen source, the mixture can also achieve V-0 and a LOI of 33% in PP at a loading of about 37.5%. It was claimed that the mixture can be easily dispersed, has excellent UV stability, and is non-blooming, nonvolatile, and odorless. However, its water absorption in high humidity areas was a deficiency of this additive. 

Research on blending milk fat and its fractions with cocoa butter to reduce costs and/or to improve stability against fat bloom in chocolates has had mixed results. Milk fat hard fractions have been reported to inhibit fat bloom formation in both milk and dark chocolates (Versteeg et al., 1994 Dimick et al., 1996b Bricknell and Hartel, 1998) but to accelerate fat bloom in compound coatings based on palm kernel oil (Ransom-Painter et al., 1997). Reddy et al. (1996) showed the importance of modifying the... 

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