Cross-linking agents hydrocarbons

There is, quite clearly, scope or a very wide range of epoxy resins. The nonepoxy part of the molecule may be aliphatic, cycloaliphatic or highly aromatic hydrocarbon or it may be non-hydrocarbon and possibly polar. It may contain unsaturation. Similar remarks also apply to the chain extension/cross-linking agents, so that cross-linked products of great diversity may be obtained. In practice, however, the commercial scene is dominated by the reaction products of bis-phenol A and epichlorohydrin, which have some 80-90% of the market shtu"e. 

Alumoxane solids are precipitated from mixtures of toluene and aliphatic hydrocarbons by addition of methylboroxine or methoxyboroxine, catechol bo-rane, ° and organic peroxides and carbonates. Reaction with metallocene dichlorides affords a catalyst for olefin polymerization in an isobutane slurry. Cross-linking agents such as /3-hydroquinone and a,ft3-diols such as 1,6-hexanedioF also precipitate MAO from toluene. In the former case, activation of Et(Ind)2ZrCl2 or Cp2ZrCl2 only occurred when additional trialkylaluminum was added. 

TVA and Differential Distillation Analysis (or SATVA) have been applied to studies on the effect of chlorinated hydrocarbon fire retardants [945, 946]. Rigby [947] has studied vapour evolution from LDPE cable insulation material (20-60 mg) by means of TVA-ToFMS, a form of in-source TD-MS, and identified Santonox R and traces of the cross-linking agent dicumyl peroxide in the low-temperature peak of the TVA curve. The TVA curves of commercial LDPE and of fl eshly prepared LDPE/Santonox suggested that in commercial samples Santonox was distributed closer to the surface than in freshly prepared ones. The detection limit (using ToF-MS) for Santonox bulk-distributed in LDPE was about 0.01%. Chiantore et al. [948] have characterised a phenol-formaldehyde (PF) resin by means of TVA (to isolate the lower-MW components) and SEC (both on volatile fractions and residues). 

H.R.Fee R.W. Lawrence, LTSP 3318740 (1967) CA 67, 55844s (1967) [An aqueous slurry-type blasting agent is provided by a mixt of 12—20% water, 1-118 (preferably 5-14%) sensitizer such as hexamethylenetetramine mononitrate (I), dinitrate or a mixt of the two, 45-65% AN, 5-20% NaNOa and 0.2-5.0 (preferably 0.5—2.0%) guar-gum thickener in cross-linked form. A supplemental sensitizer such as fine Al, Mg AI or C (or hydrocarbon oil) may be used, especially if less than 5% of... 

Sfiica impregnated with saturated and unsaturated hydrocarbons (squalene, paraffin oil), silicone and plant oils, complexing agents (silver ions, boric add and borates, unsaturated and aromatic compounds), tigands (EDTA, digitonin), and transition metal salts silanized silica gel impregnated with anionic and cationic surfactants Cross-linked, polymeric dextran gels (Sephadex)... 

Generally, neither the functionalization reaction nor the cross-linking reactions can be carried out in aqueous suspensions, because the coupling agents mentioned above react with water or are insoluble in it. Hence, water has to be completely exchanged by a liquid of low, e.g. toluene, benzene, or chlorinated hydrocarbons, or moderate donicity, e.g. acetone. These solvents allow functionalization or cross-linking under mild conditions [63, 64, 73, 74]. 

When the polymer acids are treated with metallic bases the bulk and solution properties of the neutralized products are changed markedly. In bulk the neutralized products behave as if they are covalently cross-linked. In fact, they are not covalently cross-linked since they are soluble in mixtures of hydrocarbon and polar solvents (12). Nevertheless, their solution behaviors are so significantly different from those of the base polymers and the polymeric sulfonic acids that effective neutralization is not a simple operation. If solutions containing the free polymeric sulfonic acid are treated with an aqueous solution of neutralizing agent, a gel results which prevents effective neutralization and processing. The metal sulfonates are solubilized through the inclusion of a polar cosolvent such... 

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