Inhibitors for polymers

LSP33. [Berol Nobel] NJf-Bis (3-ami-nopropyl) tallow amine iniennediate, wetting agent pigment grinding aid, dispersant flushing agent corrosion inhibitor for polymer industry. 

Ethylidene bis(4,6-di-t-butylphenol), 2,2 -Ethylidenebis(4,6-di-t-butylphenol)i EINECS 252-816-3 Phenol, 2,2 -ethylidenebis(4,6-bis(1,1-dimethyl-ethyl)- Vanox 1290, Antioxidant oxidative inhibitor for polymers process stabilizer for polyolefins stabilizer for PU and PS, Crystals mp 162-164°, Vanderbilt R.T. Co. Inc. 

Positive-Tone Photoresists based on Dissolution Inhibition by Diazonaphthoquinones. The intrinsic limitations of bis-azide—cycHzed mbber resist systems led the semiconductor industry to shift to a class of imaging materials based on diazonaphthoquinone (DNQ) photosensitizers. Both the chemistry and the imaging mechanism of these resists (Fig. 10) differ in fundamental ways from those described thus far (23). The DNQ acts as a dissolution inhibitor for the matrix resin, a low molecular weight condensation product of formaldehyde and cresol isomers known as novolac (24). The phenoHc stmcture renders the novolac polymer weakly acidic, and readily soluble in aqueous alkaline solutions. In admixture with an appropriate DNQ the polymer s dissolution rate is sharply decreased. Photolysis causes the DNQ to undergo a multistep reaction sequence, ultimately forming a base-soluble carboxyHc acid which does not inhibit film dissolution. Immersion of a pattemwise-exposed film of the resist in an aqueous solution of hydroxide ion leads to rapid dissolution of the exposed areas and only very slow dissolution of unexposed regions. In contrast with crosslinking resists, the film solubiHty is controUed by chemical and polarity differences rather than molecular size. 

Diarylamiaes are of the greatest iadustrial importance as stabili2ers and antioxidants (qv) for polymers, stabili2ers for explosives, polymeri2ation inhibitors, and ia dyes. Today, the use of these materials as antioxidants is essentially limited to derivatives of diphenylamine siace /V-phenyl-2-naphthylamine is ao longer used. 

Uses. Isoquinoline and isoquinoline derivatives are usehil as corrosion inhibitors, antioxidants, pesticides, and catalysts. They are used in plating baths and misceUaneous appHcations, such as in photography, polymers, and azo dyes (qv). Numerous derivatives have been prepared and evaluated as pharmaceuticals. Isoquinoline is a main component in quinoline stiH residue bases, which are sold as corrosion inhibitors and acid inhibitors for pickling iron and steel. 

Fire and uncontroUed polymerization are a concern in the handling of chloroprene monomer. The refined monomer is ordinarily stored refrigerated under nitrogen and inhibited. This is supported by routine monitoring for polymer formation and vessel temperature. Tanks and polymerization vessels are equipped for emergency inhibitor addition. Formalized process hazard studies, which look beyond the plant fence to potential for community involvement, are routine for most chemical processes. 

This salt is used as an inhibitor for the polymerisation of butadiene. It seems to play its role very well when its concentration is lower than 0.5%. If the concentration is greater than 5%, a black precipitate forms which contains 80% of organic polymer containing nitrate and nitrite groups in the proportions of 2 1. This solid combusts spontaneously at 150 C even when there is no air. 

The techniques of paraffin removal and paraffin prevention have been reviewed [810]. In particular, inhibitors for paraffin deposits are copolymers of ethylene with vinylacetate [525-527,1597] or polymers from p-nonylphenyl methacrylate and p-dodecylphenyl methacrylate [773]. These materials lower the pour point of the oil. It has been shown that for oils which differ in the content of n-paraffins and asphalt-resinous substances, it is necessary to use blends of copolymers of different compositions and molecular weights to obtain optimal efficiency. Polyacrylamide and wastes from the production of glycerol with a concentration of 400 mg/liter of oil have also been claimed to be effective as paraffin inhibitors [536]. 

L. Yang and B. Song. Phosphino maleic anhydride polymer as scale inhibitor for oil/gas field produced waters. Oilfield Chem, 15(2) 137-140, June 1998. 

Erdmann et al. (2000) report the fabrication of devices for the localized delivery of salicylic acid from the poly(anhydride-co-ester)s mentioned in Section II.C. A unique feature of this drug delivery system is that the drug compound is part of the polymer backbone. Devices were implanted intraorally and histopathology was reported (Erdmann et al., 2000). Chasin et al. (1990) review fabrication and testing of implantable formulations for other drugs including angiogenesis inhibitors for treatment of carcinomas and bethanechol for the treatment of Alzheimer s disease. 

Uses. Fluorinating agent incendiary igniter and propellant for rockets in nuclear reactor fuel processing pyrolysis inhibitor for fluorocarbon polymers... 

Enzyme-sensitive supramolecular polymers also hold promise in analytical applications such as the screening of enzyme inhibitors. A simple visual assay based on the hydrogelation of small molecules has been developed for screening the activities of inhibitors of enzymes like acid phosphatase. A number of inhibitors for... 

Liquid crystal polymers having 1,3-dithiane or 1,3-oxathiane rings as mesogenic side groups exhibit the extremely important liquid crystal phase at around room temperature <1999MI335>. 1,3-Oxathianes have also been applied as perfumery and flavoring ingredients other derivatives exhibit excellent herbicidal activity and 1,3-oxathiane derivatives have been employed as corrosion inhibitors for steel. 

Polymers that are protease inhibitors and polymer-inhibitor conjugates are now widely investigated for their ability to protect proteins and peptides from proteolytic degradation. These molecules are effective in the immediate area surrounding the delivery device, so the effects on proteins that have diffused far from the delivery device are limited. Due to the fact that bioadhesives were used as the conjugating polymer, the delivery device may adhere to the intestinal lining. If this does happen, the diffusional distance of the protein from the device to the intestinal wall will be quite short. One barrier that the protease inhibitors do not affect is the cellular barrier. Biomacromolecules must still find a method to enter the cells or be taken up by phagocytosis. 

When two polymeric systems are mixed together in a solvent and are spin-coated onto a substrate, phase separation sometimes occurs, as described for the application of poly (2-methyl-1-pentene sulfone) as a dissolution inhibitor for a Novolak resin (4). There are two ways to improve the compatibility of polymer mixtures in addition to using a proper solvent modification of one or both components. The miscibility of poly(olefin sulfones) with Novolak resins is reported to be marginal. To improve miscibility, Fahrenholtz and Kwei prepared several alkyl-substituted phenol-formaldehyde Novolak resins (including 2-n-propylphenol, 2-r-butylphenol, 2-sec-butylphenol, and 2-phenylphenol). They discussed the compatibility in terms of increased specific interactions such as formation of hydrogen bonds between unlike polymers and decreased specific interactions by a bulky substituent, and also in terms of "polarity matches" (18). In these studies, 2-ethoxyethyl acetate was used as a solvent (4,18). Formation of charge transfer complexes between the Novolak resins and the poly (olefin sulfones) is also reported (6). 

M. Tamura, T. Ohishi, and H. Sakurai, Diphenylamine derivatives and degradation inhibitors for rubber polymers, US Patent 4298522, assigned to Nippon Zeon Co. Ltd. (Tokyo, JP), November 3,1981. 

Ethylene glycol in the presence of an acid catalyst readily reacts with aldehydes and ketones to form cyclic acetals and ketals (60). 1,3-Dioxolane [646-06-0] is the product of condensing formaldehyde and ethylene glycol. Applications for 1,3-dioxolane are as a solvent replacement for methylene chloride, 1,2-dichloroethane, 1,1,1-trichloroethane, and methyl ethyl ketone as a solvent for polymers as an inhibitor in 1,1,1-trichloroethane as a polymer or matrix interaction product for metal working and electroplating in lithium batteries and in the electronics industry (61). 1,3-Dioxolane can also be used in the formation of polyacetals, both for homopolymerization and as a comonomer with formaldehyde. Cyclic acetals and ketals are used as protecting groups for reaction-sensitive aldehydes and ketones in natural product synthesis and pharmaceuticals (62). 

Fe(CN)6]3, as the free acid, has been used as a corrosion inhibitor for metal surfaces 55 K2[Fe(CN)6] has also been reported as being effective for this purpose.56 Both hexacyano ions act as combustion inhibitors for aromatic polymers.57 In the production of carbon monoxide by coke gasification for use in blast furnaces, additives are needed to enhance the reduction of any carbon dioxide formed back to the monoxide. Trisoxalatoiron has been found effective for this... 

An ideal inhibitor for a polymerization introduces an induction period during which it is completely converted into substances which have no subsequent effect upon the polymerization. When the inhibitor is completely consumed, polymerization proceeds at the rate to be expected for a similar reaction performed in the absence of inhibitor due allowance must be made for consumption of initiator during the induction period. Even in an ideal case however there must be a transition between complete inhibition and the full rate of reaction because, at very low concentrations of the inhibitor, the monomer may compete successfully for the capture of radicals in the system. An ideal inhibitor should not become incorporated in polymer except for the possibility of it becoming included in the low polymer formed during the transition period. 

Recently, a new class of inhibitors (nonionic polymer surfactants) was identified as promising agents for drug formulations. These compounds are two- or three-block copolymers arranged in a linear ABA or AB structure. The A block is a hydrophilic polyethylene oxide) chain. The B block can be a hydrophobic lipid (in copolymers BRIJs, MYRJs, Tritons, Tweens, and Chremophor) or a poly(propylene oxide) chain (in copolymers Pluronics [BASF Corp., N.J., USA] and CRL-1606). Pluronic block copolymers with various numbers of hydrophilic EO (,n) and hydrophobic PO (in) units are characterized by distinct hydrophilic-lipophilic balance (HLB). Due to their amphiphilic character these copolymers display surfactant properties including ability to interact with hydrophobic surfaces and biological membranes. In aqueous solutions with concentrations above the CMC, these copolymers self-assemble into micelles. 

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