Nonvolatile plasticizers

Oxidized castor oils are excellent nonmigrating, nonvolatile plasticizers (qv) for ceUulosic resins, poly(vinyl butyral), polyamides, shellac, and natural and synthetic mbber (see Rubber, natural). The high viscosity products are also used as tackifiers in gasket compounds and adhesives (qv) because of good oil and solvent resistance. They also serve as excellent pigment grinding media and as a base for inks (qv), lubricating oils, and hydrauHc oils (62). 

Thus, DINA is seen from the above data to be markedly less stable to heat than Tetryl. This lack of stability was indicated to be due to the presence of an impurity, Di(nitroxylethyl)-nitrosamine, which might be removed by heating Uses, DINA has been proposed as a nonvolatile plasticizer for NC, and its use in place of NG has been suggested. Kincaid... 

This compd has expl props which are reported by Blomquist (Ref 3). It was patented as a nonvolatile plasticizer for NC used in proplnts... 

R. N(NO,). CH,. CH,. N(NO,). CM,. CH, r ONO, were recently patented by Blom-quist ft Fiedorek (Ref 3) for use in propellants as explosive, practically nonvolatile plasticizers for NO These compds can be prepd either by the method of Franchimont ft Klobbie (Ref 1), which involves the treatment of... 

The first step in the synthesis of nonvolatile plasticizers - which are of increasing importance - is hydroformylation of a long-chain olefin, for which rhodium phosphite catalysts have very useful properties. The current use of sterically hindered phosphites as antioxidants for polyalkenes together with their much simpler... 

Although instances of lyotropic PLCs predate studies of thermotropic PLCs, as they involved solutions of comparatively esoteric species — virus particles and helical polypeptides — studies of these liquid crystals were isolated to a few laboratories. Nevertheless, observations on these lyotropic PLCs did stimulate the first convincing theoretical rationalizations of spontaneously ordered fluid phases (see below). Much of the early experimental work was devoted to characterizing the texture of polypeptide solutions. (23) The chiral polypeptides (helical rods) generate a cholesteric structure in the solution the cholesteric pitch is strongly dependent on polymer concentration, dielectric properties of the solvent, and polymer molecular weight. Variable pitch (<1 - 100 pm) may be stabilized and locked into the solid state by (for example) evaporating the solvent in the presence of a nonvolatile plasticizer.(24)... 

In a typical formulation, an ethylene-n-butylacrylate-carbon monoxide (60/30/ 10) terpolymer (60 wt%) is melt compounded in a twin-screw extmder with PVC (30 wt%) along with an optional, nonvolatile plasticizer such as trioctyl trimellitate (10 wt%) such that the ethylene terpolymer dispersion was cured in situ during the mixing by catalytic amounts of a suitable peroxide (0.3 %) and a bismaleimide crosslink promoter (0.2 %). It is believed that the initial homogeneous miscible melt blend later forms the micro phase-separated mbber domains as the selective rubber cross-Unking progresses. Currently, such TPV blends are commercially sold as Alcryn melt-processable rubbers by Advanced Polymer Alloys division of Ferro. 

At higher temperatures, where aging also plays a role, the compression set curves are at a lower level than for a large number of other elastomers. It is important to use M-types of CR, heat-resistant antioxidants, and nonvolatile plasticizers. 

Hardening of highly plasticized rolls in service is a common problem, especially in the printing industry. The use of a liquid NBR, such as those in Table 2.12, to replace part of the plasticizer provides a nonvolatile plasticizer that reduces the tendency for rolls to harden in service. Polymeric plasticizers are another alternate. 

Another class of solvent-based dispersion is the organosols. In this case, vinyl chloride copolymer resins are dispersed in suitable nonvolatile plasticizers and solvent. The solvent is evaporated and the remaining film is heated to approximately 177 °C. The heat helps dissolve the resin in the plasticizer, and a tough, flexible film is obtained upon cooling to room temperature. The major polymers used for solvent-based adhesives are listed in Table 8.10. 

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