Polyolefineic acids

Reference may be made here to a procedure for separating mixtures of mono-olefinic fatty acids and for subsequently determining the structure of the components [11]. This method utilises two-dimensional TLC on silica gel, impregnated with paraffin and silver nitrate a similar procedure is described in [225]. A scheme for determination of the position and configuration of the double bonds in polyolefinic acids [170] depends on partial hydrogenation with hydrazine, separation of the reduction products through argentation-TLC and determination of... 

A newer self-intumescent phosphoric acid salt has been introduced by Albright WHson as Amgard EDAP, mainly as an additive for polyolefins. It is a finely divided soHd, mp 250°C, having a reported phosphoms content of 63 wt % as H PO. It appears to be the ethylenediamine salt of phosphoric acid (1 1). Unlike ammonium polyphosphate, it does not require a char-forming synergist (62). 

Other simple nickel salts of organic acids include the oxalate [20543-06-0] oleate [68538-38-5], and stearate [2223-95-2]. The latter two have been used as oil-soluble nickel forms in the dyeing of synthetic polyolefin fibers (see Driers and metallic soaps). Nickel oxalate has been used as a catalyst intermediate (59). 

A major use for 2,4-di-/ f2 -amylphenol is in the production of uv stabilizers the principal one is a benzotriazole-based uv absorber, 2-(2 -hydroxy-3, 5 -di-/ f2 -amylphenyl)-5-chlorobenzotriazole [25973-55-17, which is widely used in polyolefin films, outdoor furniture, and clear coat automotive finishes (56). Another significant use for 2,4-di-/ f2 -amylphenol is in the photographic iadustry. A number of phenoxyacetic acid derivatives of... 

Mixtures of a titanium complex of saturated diols, such as TYZOR OGT, and a titanium acylate, such as bis- -butyl-bis-caproic acid titanate, do not have a yellowing or discoloring effect on white inks used to print polyolefin surfaces (506). The complexes formed by the reaction of one or two moles of diethyl citrate with TYZOR TPT have an insignificant color on their own and do not generate color with phenol-based antioxidants (507). The complexes formed by the addition of a mixture of mono- and dialkyl phosphate esters to TYZOR TBT are also low color-generating, adhesion-promoting additives for use in printing polyolefin films (508). 

Metal salts of neodecanoic acid have also been used as catalysts in the preparation of polymers. For example, bismuth, calcium, barium, and 2kconium neodecanoates have been used as catalysts in the formation of polyurethane elastomers (91,92). Magnesium neodecanoate [57453-97-1] is one component of a catalyst system for the preparation of polyolefins (93) vanadium, cobalt, copper, or kon neodecanoates have been used as curing catalysts for conjugated-diene butyl elastomers (94). 

Cyanoacrylate adhesives cure by anionic polymerization. This reaction is catalyzed by weak bases (such as water), so the adhesives are generally stabilized by the inclusion of a weak acid in the formulation. While adhesion of cyanoacrylates to bare metals and many polymers is excellent, bonding to polyolefins requires a surface modifying primer. Solutions of chlorinated polyolefin oligomers, fran-sition metal complexes, and organic bases such as tertiary amines can greatly enhance cyanoacrylate adhesion to these surfaces [72]. The solvent is a critical component of these primers, as solvent swelling of the surface facilitates inter-... 

A WBL can also be formed within the silicone phase but near the surface and caused by insufficiently crosslinked adhesive. This may result from an interference of the cure chemistry by species on the surface of substrate. An example where incompatibility between the substrate and the cure system can exist is the moisture cure condensation system. Acetic acid is released during the cure, and for substrates like concrete, the acid may form water-soluble salts at the interface. These salts create a weak boundary layer that will induce failure on exposure to rain. The CDT of polyolefins illustrates the direct effect of surface pretreatment and subsequent formation of a WBL by degradation of the polymer surface [72,73]. 

Oridation. This is caused by contact with oxidising acids, exposure to u-v, prolonged application of excessive heat, or exposure to weathering. It results in a deterioration of mechanical properties (embrittlement and possibly stress cracking), increase in power factor, and loss of clarity. It affects most thermoplastics to varying degrees, in particular polyolefins, PVC, nylons, and cellulose derivatives. 

Blends based on polyolefins have been compatibilized by reactive extrusion where functionalized polyolefins are used to form copolymers that bridge the phases. Maleic anhydride modified polyolefins and acrylic acid modified polyolefins are the commonly used modified polymers used as the compatibilizer in polyolefin-polyamide systems. The chemical reaction involved in the formation of block copolymers by the reaction of the amine end group on nylon and anhydride groups or carboxylic groups on modified polyolefins is shown in Scheme 1. 

Scheme 1 The proposed acid/amine and anhydride/ amine reaction between carboxylic groups/anhydride groups on modified polyolefins and amine end groups on Nylon-6.

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