Plastics additives antioxidants

The substituted phenols and cresols constitute about half the total volume of this group. Para-t-butylphenol is produced by the alkylation of phenol with isobutylene. The principal applications for this derivative are in the manufacture of modified phenolic resins for the rubber industry and in surface coatings. BHT is obtained from isobutylene and p-cresol. Technical-grade BHT is an antioxidant for plastics and elastomers, and is a gum inhibitor in gasoline. Food-grade BHT is an antioxidant in edible oils, preserves, and many other foods. 2,6-Di-t-butylphenol is used to produce a wide range of plastics additives, antioxidants, and gasoline additives. 

Organophosphoms compounds, primarily phosphonic acids, are used as sequestrants, scale inhibitors, deflocculants, or ion-control agents in oil wells, cooling-tower waters, and boiler-feed waters. Organophosphates are also used as plasticizers and flame retardants in plastics and elastomers, which accounted for 22% of PCl consumed. Phosphites, in conjunction with Hquid mixed metals, such as calcium—zinc and barium—cadmium heat stabilizers, function as antioxidants and stabilizer adjutants. In 1992, such phosphoms-based chemicals amounted to slightly more than 6% of all such plastic additives and represented 8500 t of phosphoms. Because PVC production is expected to increase, the use of phosphoms additive should increase 3% aimually through 1999. 

Many additives are used with PVC polymers such as plasticizers, antioxidants, and impact modifiers. Heat stabilizers, which are particularly important with PVC resins, extend the useful life of the finished product. Plastic additives have been reviewed by Ainsworth. 

An important item to note is that most commercially used plastics are not single component pure substances. Practically always, the basic polymer itself, rarely if ever a single molecular species, is compounded with other components such as plasticizers, pigments, antioxidants, and other additives. More often than not, then, biological susceptibility is due to the nonpolymer component. 

Applications The broad industrial analytical applicability of microwave heating was mentioned before (see Section 3.4.4.2). The chemical industry requires extractions of additives (antioxidants, colorants, and slip agents) from plastic resins or vulcanised products. So far there have been relatively few publications on microwave-assisted solvent extraction from polymers (Table 3.5). As may be seen from Tables 3.27 and 3.28, most MAE work has concerned polyolefins. 

FD-MS is also an effective analytical method for direct analysis of many rubber and plastic additives. Lattimer and Welch [113,114] showed that FD-MS gives excellent molecular ion spectra for a variety of polymer additives, including rubber accelerators (dithiocar-bamates, guanidines, benzothiazyl, and thiuram derivatives), antioxidants (hindered phenols, aromatic amines), p-phcnylenediamine-based antiozonants, processing oils and phthalate plasticisers. Alkylphenol ethoxylate surfactants have been characterised by FD-MS [115]. Jack-son et al. [116] analysed some plastic additives (hindered phenol AOs and benzotriazole UVA) by FD-MS. Reaction products of a p-phenylenediaminc antiozonant and d.v-9-lricoscnc (a model olefin) were assessed by FD-MS [117],... 

On Table I is a list of the major end uses for the new chemicals submitted up through the end of 1981. Intermediates in the manufacture of other chemicals, polymers for a variety of end uses but mainly for paints and coatings, and additives such as flame retardants, plasticizers and antioxidants for plastics account for over half of all the uses of these new chemicals. These seven major categories in total represent slightly over three fourths of all projected uses. One would suspect that this pattern will change with market demand and competitive developments and a year from now we might see intense R D activity in some other specific market areas culminate in the introduction of a line of new chemical substances. 

Some derivatives of 1,2,3-trithiolane have been used as starting materials for sulfur-containing polymers <84MI 4l5-0l>. Industrial applications for 1,2,3-trithiolane derivatives include their use as high-pressure lubricant oil additives <88EGP258606>, plasticizers and antioxidants <89EGP263770>. 

Karayannidis G P, Sideridon 1 D and Zamboulis D X (1998) Antioxidants for poly(ethylene terephtha-late), In Plastics additives, an A-Z reference, Pritchard G (Ed), Chapman Hall London, pp 95-107. 

This chapter contains information on additives such as crosslinking agents, processing aids, retarders and stearates. While these compounds may not be as widely used as plasticizers or antioxidants, they play an important role in plastic and mbber processing. 

Use Organic synthesis, for derivation of plasticizers, polymers, antioxidants oil additives. 

Alternatively, the container may contain an opacifying agent, e.g., titanium dioxide. The use of multilayered bags was demonstrated to inhibit photochemical decomposition of vitamin E in TPN fat emulsions (Allwood and Martin, 2000). PVC films discolor on irradiative exposure due to photochemical degradation of the polymer (Hollande and Laurent, 1997). Plastic containers for parenteral use may contain several additives, e.g., antioxidants, stabilizers, plasticizers, lubricants, impact modifiers, and coloring matter when justified and authorized. In an appendix, the European Pharmacopoeia presents a list of plastic additives that may be used (European Pharmacopoeia, 2002). The additives should not be extracted by the contents in such quantities as to alter efficacy or stability of the product or to present any risk of toxicity (European Pharmacopoeia, 2002). However, organic additives extracted in concentrations below the detection limits of the analytical methods authorized by the European Pharmacopoeia may be sufficient to initiate photosensitized reactions in the formulation. 

Ethanethiol is used as an intermediate in the manufacture of insecticides, plastics, and antioxidants and as an additive to natural gas to give odor. It occurs in illuminating gas and in petroleum distillates. 

Mold-Release Agents Plasticizers Stabihzers Antioxidants PVC Heat Stabilizers UV Stabihzers Thermoplastic Materials Thermoset Materials Classified Directory of Suppliers (Primary Equipment, Auxiliary Equipment, Materials, Chemicals and Additives, Specialized Services)... 

---