Rubber, solvent extraction

Mono, di and triethylene glycols Mixtures of water and dioxane or acetone Nitrile- Flame siloxane ionisation rubber Solvent extract acetylated in presence ofBF4 2mg L1 [224]... 

Plasticiser/oil in rubber is usually determined by solvent extraction (ISO 1407) and FTIR identification [57] TGA can usually provide good quantifications of plasticiser contents. Antidegradants in rubber compounds may be determined by HS-GC-MS for volatile species (e.g. BHT, IPPD), but usually solvent extraction is required, followed by GC-MS, HPLC, UV or DP-MS analysis. Since cross-linked rubbers are insoluble, more complex extraction procedures must be carried out. The determination of antioxidants in rubbers by means of HPLC and TLC has been reviewed [58], The TLC technique for antidegradants in rubbers is described in ASTM D 3156 and ISO 4645.2 (1984). Direct probe EIMS was also used to analyse antioxidants (hindered phenols and aromatic amines) in rubber extracts [59]. ISO 11089 (1997) deals with the determination of /V-phenyl-/9-naphthylamine and poly-2,2,4-trimethyl-1,2-dihydroquinoline (TMDQ) as well as other generic types of antiozonants such as IV-alkyl-AL-phenyl-p-phenylenediamines (e.g. IPPD and 6PPD) and A-aryl-AL-aryl-p-phenylenediamines (e.g. DPPD), by means of HPLC. 

Reflux extraction of additives and wax from polyolefins was reported [116]. Subsequently, the additives were adsorbed onto an adsorbent (Florisil) and the wax was removed from the extract before chromatography. Boiling extractions of SBR are described in ASTM D 1416-89 1 g of rubber is extracted by boiling in two 100 mL portions of 75/25 vol% isopropyl alcohol/toluene. Reflux heating with strong solvents, such as THF, dichloromethane or chloroform has been reported [117]. Reflux extraction has also been used for the 3 h extraction of caprolactam and oligomers from PA6 in boiling methanol. 

Applications Open-column chromatography was used for polymer/additive analysis mainly in the 1950-1970 period (cf. Vimalasiri et al. [160]). Examples are the application of CC to styrene-butadiene copoly-mer/(additives, low-MW compounds) [530] and rubbers accelerators, antioxidants) [531]. Column chromatography of nine plasticisers in PVC with various elution solvents has been reported [44], as well as the separation of CHCI3 solvent extracts of PE/(BHT, Santonox R) on an alumina column [532]. Similarly, Santonox R and Ionol CP were easily separated using benzene and Topanol CA and dilaurylthiodipropionate using cyclohexane ethyl acetate (9 1 v/v) [533]. CC on neutral alumina has been used for the separation of antioxidants, accelerators and plasticisers in rubber extracts [534]. Column chromatography of polymer additives has been reviewed [160,375,376]. 

Uses Solvent for waxes, resins, dyes, animal, vegetable and mineral oils paint and varnish removers rubber cements extracting acetic acid from solution spotting compositions rubber cements oxygenate in gasoline organic synthesis. 

Figure 10 shows a spectrum of butyl rubber gum stock obtained on the solid at 80°C using normal pulsed FT techniques. Clearly it could be identified as a component in fabricated materials by direct nmr spectral analysis. Figure 11 shows spectra obtained from various portions of typical rubber products. These samples were cut from the rubber product, placed in an nmr tube without solvent, and spectra obtained at an elevated temperature. The data show how polyisoprene, a polyisoprene/polybutadiene blend and a polyisobutylene/polyisoprene/polybutadiene rubber blend are quickly identified in the materials. Figure 11a shows processing oil was present, and which was confirmed by solvent extraction. 

Analysis of ebonite is more difficult than that of ordinary vulcanised rubber, as it is less readily attacked by solvents the sample for analysis should be finely powdered. The determinations of moisture, ash, sulphur, etc., are made as in manufactured rubber the extraction with acetone should be prolonged, sometimes to 1-2 days, to be complete. The residue insoluble in acetone is extracted first with epichlorhydrin for 3 hours to remove resins insoluble, or almost so, in acetone (copal, mastic, amber) and then with pyridine as indicated for manufactured rubber next comes the treatment with alcoholic potash to dissolve any brown factis present. The residue from this last treatment comprises the pure rubber, the sulphur combined therewith and the mineral matter in one part of it the ash and the sulphur of the ash are determined, and in another the total sulphur, the sulphur united with the rubber being obtained by difference the pure rubber is then calculated by difference. 

TG-MS is an ideal technique for identifying residual volatiles in polymers. The detection of residual volatiles (and of other impurities) can often yield clues as to manufacturing processes. In many cases, such as in the determination of highly volatile materials, of residual solvents or plasticisers, use of TG-MS is requested. Specifically, there are reports on the entrapment of curing volatiles in bismaleimide laminates [145] and elastomers [48], on the detection of a curing agent (dicumylperoxide) in EPDM rubbers and of bromine flame retardants in electronic waste [50], of plasticisers such as bambuterol hydrochloride [142] or TPP and diethylterephthalate in cellulose acetate [143], on solvent extraction and formaldehyde loss in phenolic resins [164], and on the evolution of toxic compounds from PVC and polyurethane foams [146]. 

Bromoform is used as a chemical intermediate in the synthesis of organic chemicals and pharmaceuticals. It is used as an ingredient in fire-resistant chemicals and as an industrial solvent in liquid-solvent extractions. Bromoform is used in polymer reactions and in the vulcanization process for rubber. Bromoform is also used for medicinal purposes as a sedative, an-titussive, and antiseptic. 

Ethylamine is primarily used in the production of triazine herbicides. Ethylamine has also found use in resin chemistry, oil refining, and solvent extraction as a stabilizer for latex rubber and in the manufacture of dyestuffs, medicinals, corrosion inhibitors, urethane foam catalysts, and agents used in wash-and-wear fabrics. 

Pentane is present in volatile petroleum fractions and is used (1) as a fuel (2) in the production of ammonia, olefin, and hydrogen (3) in the manufacture of artificial ice (4) in low-temperature thermometers (5) as a blowing agent for plastics and foams and (6) in solvent extraction processes. Neopentane is important in the manufacture of rubber. 

Use Dye intermediate, solvent extraction, petroleum refining, stabilizer for rubber latex, detergents, organic synthesis. 

In laboratory practice, a small sample of rubber is extracted with solvent (usually toluene) at room temperature for a specified period of time (1 week) and the percentage of bound rubber, Rb, is calculated from the equation ... 

CaCO EPR rubber rubber silicone maleates fatty acid silanes PDMS decreased disperse component of the surface energy filler surface energy approaches surface energy of matrix decreased tensile strength and flexural cracking increased green strength, Mooney viscosity, and tensile properties surface hydrophobization resistance to solvent extraction and water 21 49 49 37... 

The solvent extraction experiments coupled with DSC and FTIR data show that the degree of cure of these mixtures, under identical irradiation and bake conditions, is dependent on the concentration and nature (% acrylonitrile) of the rubber modifier. The sol fractions for PCI cured epoxy films with three different rubber modifiers (5), ETBN-13 (27% CN), ETBN-8 (17% CN) and ETBN-15 (KMTCN) at a range of concentrations are shown in Figure 2. The data show that a decrease in extent of cure occurs with increased rubber concentration and that this decrease (ETBN-13 > ETBN-8 > ETBN-15) may be correlated to the percent acrylonitrile in the rubber modifier. This is supported by the FT-IR spectra of two of these mixtures (IV and VI) as shown in Figure 3 and the quantitative measure of the extent of cure as a function of irradiation time for mixtures V (30% TBN-13) and VIII (30% ETBN-15) as compared to mixture IX (no rubber) silicon in Figure 4 (8). 

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