Plastics Processing stabilizers

TMETN is a liquid at room temperature and the production process of NG-TMETN propellants is the same as that described for NG-NG propellants. The shock sensitivity of TM ETN is sufficiently lower than that of NG that no desensitizers are needed for NC-TMETN propellants. Instead of the DEP or TA used as low energy density plasticizers and stabilizers of NC-NG propellants, TMETN is mixed with TEGDN, which is a dinitrate ester and hence a relatively high energy density material. Thus, the overall energy density of double-base propellants composed of NC-TMETN is equivalent to or even higher than that of NC-NG double-base propellants. 

Akutin (52) performed an exhaustive study on the influence of processing conditions and the nitrile rubber/poly(vinyl chloride) ratio on the mechanical characteristic of the product. The experiments were carried out in a Brabender Plastograph at 160-180° C and rotor speed of 10-50 rpm. The polyfvinyl chloride) molecular weight was 83500. A resin with an epoxy group content of 20.75% was added to the blend as plasticizer and stabilizer. Figure 29 shows that the... 

Dibutylphthalate is used as a solv for aromatic nitrocompds, such as DNT Di-nitroethylbenzene. Silk (Ref 2) patented its use for the coating of NC NG propellants to serve as a deterrant, solvent, plasticizer 8e stabilizer. It is added during the mixing process of the propellant colloid and replaces a portion of the volatile solvent, thus reducing the possibility of the loss of vol solv. It functions in the burning of pro--pellants to cool the of combustion below... 

Tile is based mainly on vinyl chloride and vinyl acetate copolymers. Some polypropylene tile systems have recently been introduced. A petroleum resin is usually employed as an extender and processing aid conventional vinyl plasticizers and stabilizers also are incorporated. Reinforcing fibers and limestone constitute the remainder of the tile composition the fibers contribute hot strength for processing and dimensional stability in the finished tile, limestone supplies bulk at an economical cost. Stable pigments are also incorporated. Since tile is installed on and below grade level, it is important that the finished product be resistant to the effects of moisture and alkali. 

This anhydrous zinc borate is recommended for use in engineering plastics processed at temperatures higher than 300°C which is the upper limit of Firebrake ZB processing temperature. It is reported to be an effective smoke suppressant in chlorofluoropolymers for plenum cable applications.66 Recently it was claimed that this anhydrous zinc borate can replace antimony oxide (or sodium antimonate) completely in high temperature polyamide applications. Like its hydrated analog, this anhydrous zinc borate can also improve CTI, thermal stability, and the color stability of polyamide containing halogen sources.67 68... 

Mechanisms of Degradation Inhibitors. The degradation mechanisms described above have no little effect on end-use stability and processing stability of polypropylene. Indeed, without stabilizers and antioxidants to inhibit such degradation reactions, polypropylene would have limited usefulness as a structural plastic if any usefulness at all. 

Hindered phenols and dialkylhydroxylamines protect plastics against thermal oxidation. Alkylated benzo[b]furane-2(3H)-ones was introduced very recently as a processing stabilizer for polyolefins. 

Before its conversion into plastic products the resulting resin is almost always compounded with various additives of different nature and constitution, meant to improve processing, stability, or mechanical specifications as a function of a given application (outdoors, i.e. UV-light exposed, oxidation, high-temperature processing). Such additives are regularly used as ... 

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