Fillers embrittlement

As impact modifiers and/or processing aids (permanent plasticizer), they improve economics by increasing filler loading without embrittlement to produce ... 

Sulfite paper has a relatively short life span, since residual acid will continue to hydrolyze the cellulose and cause embrittlement. Further sources of acid include aluminum sulfate (which is added together with resin to suppress bleeding or feathering of ink into the paper) and S02 and NO from the atmosphere. Much of the world s library collections and archives will soon be lost as the paper crumbles. Various deacidification treatments (e.g., with ammonia, morpholine, cyclohexylamine carbamate, or diethyl-zinc) have been proposed and tried, but at best they can only halt the process of embrittlement and cannot reverse it.14 With the move to kraft pulping, alkaline peroxide bleaching, and increasing use of precipitated calcium carbonate as a filler, the high quality papers produced today are intrinsically acid free and should also resist subsequent acidification by S02-polluted air fairly well. 

In this paper we discuss (1) small main-chain motions and their effect on the flow processes, (2) the embrittlement of polycarbonate, (3) the formation of microvoids from sample preparation and their effect on the brittleness of polymer glasses, and (4) the modification of the degree of brittleness of polymer glasses at the filler interface in polymer composites. 

Note that in recent studies the embrittlement of ABS by fillers was alleviated by reducing interfacial adhesion (9). 

Long-term heat-aging effects of heat stabilizers. Along with melt-processing stability, different AO formulations and concentrations can extend the useful lifetimes of heat-exposed products well past that of unstabilized base HOPE. If fillers such as carbon black are added, heat-resistance to embrittlement may be extended even longer. 

Typical manifestations of embrittlement are obvious in a number of measurements, such as impact strength more detailed studies tend to confirm frequent adverse effects on ductility. For example, in the investigation of filled epoxy resins by Moehlenpah et ai (1970, 1971) cited previously, it was foui)d that, for both compressive and tensile loading, filling raised the temperature for the brittle-ductile transition at a given strain rate. In other words, the filled material was brittle at higher temperatures and lower strain rates than the unfilled polymer. The effect of filler on the ductile to ductile-rubbery transition was, on the other hand, much less. 

Brazing of CoCr-alloys can be performed either in a hydrogen atmosphere or in vacuum. As filler metals Ni- or Co-base alloys or Au-Pd-alloys can be used. In order to achieve a better wetting by the filler metals an electroplating or flashing with Ni is performed. Copper filler metals should be avoided because of the danger of an embrittlement of the seam. Table lb.8 shows the compositions of a typical Co-base filler metal. 

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