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Promoters cross-linking

Free radicals generated in butadiene-based elastomers promote cross-linking or growth of the molecular weight. These reactions lead to the increase in molecular weight or gelation. This is clear... [Pg.497]

The cross-hnking efhciency of EP copolymer has been investigated by some workers [368,371] and the yield is found to increase with increasing ethylene content. The value lies closer to PP homopolymer. The amounts of cross-hnking as well as scission have been observed to increase with increasing diene content, the labile point. Cross-linking enhancers like chlorobenzene, nitrous oxide, allylacrylate, and A-phenylmaleimide are reported to promote cross-linking [85,370,371]. [Pg.882]

Consist of a range of chemicals which promote cross-linking can initiate cure by catalysing ( catalysts , hardeners, initiators), speed up and control cure (activators, promoters) or perform the opposite function (inhibitors) producing thermosetting compounds and specialised thermoplastics (e.g. peroxides in polyesters, or amines in epoxy formulations). The right choice of a cure system is dependent on process, process temperature, application and type of resin. [Pg.777]

Experiments on cross-linking by irradiahon have revealed that in many cases the cross-link densities equivalent to those obtained by conventional methods of cross-linking require relatively high radiation doses. Therefore, a great deal of experimental work has been done on the use of additives, which promote cross-linking by irradiation. Such compounds are called radiation cross-link promoters or prorads. [Pg.91]

Boron Mechanism. Boron functions as a flame retardant in both the condensed and vapor phases. Under flaming conditions boron and halogens form the corresponding trihalide. Because boron (rihalides are effective Lewis acids, they promote cross-linking, minimizing decomposition of the polymer into volatile flammable gases. These trihalides arc also volatile thus they vaporize into the (lame and release halogen which Ihen functions as a Maine inhibitor. [Pg.639]

In the same study4, the use of XPS allowed to study the effect of surface water and added base on the interaction of the amine with the surface. Surface water appeared to play an important role in the promotion of amine-to-surface interaction. The addition of triethylamine in the reaction mixture reduces the surface interaction. The base promotes cross-linking and/or surface siloxane bond formation, either of which leaves the amino group in the free form. [Pg.245]

The zinc species (such as, zinc chloride and zinc hydroxychloride) in the condensed phase can alter the pyrolysis chemistry by catalyzing the dehydrohalogenation and promoting cross-linking, resulting in increased char formation and a decrease in both smoke production and flaming combustion. [Pg.231]

Fig. 2. Printed alginic acid (2% in 0.25M CaCl2 buffer) tubes. CaCl2 is known to promote cross-linking of alginate, producing a resultant 3D construct. Picture was... Fig. 2. Printed alginic acid (2% in 0.25M CaCl2 buffer) tubes. CaCl2 is known to promote cross-linking of alginate, producing a resultant 3D construct. Picture was...
INTEX BINDER 18 is also suggested as a nonwoven binder, particularly where a soft hand is desired. Addition of 1.5 to 2.0% of a latent acid catalyst, such as ammonium chloride, is also recommended to promote cross-linking of the polymer. [Pg.406]

The reactive additives applied in this procedure are typically vinyl monomers and/or oligomers, with one or more double bond, capable of radiation initiated chain reactions. The reactive additives — applied in moderate concentrations, — may form short side-chains and this way cross-linking bridges between the components to be compatibilized. The whole process may also be considered as promoted cross-linking, or graft - cross-linking. [Pg.67]

The situation is not any simpler with negative resists. In this case, light exposure promotes a cross-linking reaction that makes the material resistant to the solvent for the unexposed material. Typical solvents include xylene and other aromatic solvents. A typical example is a polyisopropene matrix and a promoter that is photosensitive, for example bis-arylazide. Upon photoactivated reaction, the promoter cross-links the matrix thereby substantially increasing the molecular weight of the molecules. [Pg.327]

The second kind is that of polyfunctional agents that could promote cross-linking (against chain scissioning). Trimethylol propane trimethacrylate (TMPTMA), trimethylol propane triacrylate (TMPTA) or triallyl isocyanurate (TAIC) belong to this category (Figure 9.3). [Pg.267]

Copolymers as water dispersion have also been synthesized by emulsion polymerization in presence of poly(vinyl alcohol) as protective colloid and evaluated as wood adhesives. The corresponding polymer films have been subjected to mechanical characterization. An improvement in the water and solvent resistance has been observed due to the presence of drying oils. The cobalt acetate, if present as ceitalyst in the adhesive formulation, promotes cross-linking and produces a positive effect on the adhesive performance. [Pg.328]


See other pages where Promoters cross-linking is mentioned: [Pg.457]    [Pg.190]    [Pg.219]    [Pg.54]    [Pg.99]    [Pg.275]    [Pg.166]    [Pg.136]    [Pg.155]    [Pg.337]    [Pg.573]    [Pg.219]    [Pg.93]    [Pg.194]    [Pg.88]    [Pg.164]    [Pg.77]    [Pg.106]    [Pg.10]    [Pg.203]    [Pg.776]    [Pg.166]    [Pg.355]    [Pg.349]    [Pg.319]    [Pg.320]    [Pg.22]    [Pg.47]    [Pg.454]    [Pg.88]    [Pg.164]    [Pg.571]    [Pg.275]    [Pg.148]    [Pg.262]    [Pg.73]   
See also in sourсe #XX -- [ Pg.238 ]




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