Cold cure

Medicine. The polymethacrylates have been used for many years in the manufacture of dentures, teeth, denture bases, and filling materials (116,117) (see Dental materials). In the orthodontics market, methacrylates have found acceptance as sealants, or pit and fissure resin sealants which are painted over teeth and act as a barrier to tooth decay. The dimensional behavior of curing bone-cement masses has been reported (118), as has the characterization of the microstmcture of a cold-cured acryUc resin (119). Polymethacrylates are used to prepare both soft and hard contact lenses (120,121). Hydrogels based on 2-hydroxyethyl methacrylate are used in soft contact lenses and other biomedical appHcations (122,123) (see Contactlenses). 

Vinyl ester resins generally offer mechanical properties superior to those of polyester matrices but at an increased cost. Vinyl esters are chemically similar to epoxy resins but are manufactured via a cold-curing process similar to that used in the manufacture of polyester resins. Vinyl esters offer superior resistance to water and chemical attack and are used in such appHcations as underground pipes, tank liners, and storage tanks (see Vinyl polymers). 

Requirements for heat- and cold-curing denture-base resins prepared from powder—liquids, gels, preopolymerized blanks, and fluid resins composed of acryflc, vinyl, and polystyrene polymers are given in ANSI/ADA specification no. 12 for denture-base polymers. 

Special-Purpose Resins, Repair Resins. Fractured acryflc dentures can be repaired with materials similar in composition to cold-cured denture resins. These materials generally cure more rapidly because of the relative simple manipulations involved. The process is quick and there is fltde dimensional change, but the strength of the repaired denture may be only half that of the original appliance (213). Test methods and requirements of these materials are given in ANSI/ADA specification no. 13 for denture cold-curing repair resins. 

DET 10-11 20 min room temp. yes 110 cold curing general purpose... 

Cold-curing foams use polyethers of somewhat higher molecular weight (-4500-6000) and which have a higher proportion of primary hydroxyls than are used for hot moulding. In addition the isocyanates used have a functionality greater than 2, this being achieved by the use of modified isocyanates. 

The rubbers are also used for such diverse applications as blood transfusion tubing capable of sterilisation, antibiotic container closures, electric iron gaskets, domestic refrigerators and non-adhesive rubber-covered rollers for handling such materials as confectionery and adhesive tape. The cold-curing rubbers are of value in potting and encapsulation. 

Use in cold-cure process of vulcanizing in the proofing of cloth with rubber... 

Parallam, or laminated strand lumber (LSL) is a beam made by a continuous manufacturing process composed of bigger-size wood needles (very elongated wood particles) reassembled with a structural exterior grade adhesive, the favorite adhesive being isocyanates (pMDI) when heat-curing and PRFs when cold-curing. 

In more recent times, large doses of vitamin C have been claimed to prevent the common cold, cure infertility, delay the onset of symptoms in acquired immunodeficiency syndrome (AIDS), and inhibit the development of gastric and cervical cancers. None of these claims have been backed by medical evidence, however. In the largest study yet done of the effect of vitamin C on the common cojd, a meta-analysis of more than 100 separate trials covering 40,000 people found no difference in the incidence of colds between those who took supplemental vitamin G regularly and those who did not. When taken during a cold, however, vitamin C does appear to decrease the cold s duration by 8%. 

For a number of applications curing at room temperature is desirable. This so-called cold cure is brought about by using a peroxy initiator in conjunction with some kind of activator substance. The peroxy compounds in these cases are substances such as methyl ethyl ketone peroxide and cyclohexanone peroxide, which as used in commercial systems tend not to be particularly pure, but instead are usually mixtures of peroxides and hydroperoxides corresponding in composition approximately to that of the respective nominal compounds. Activators are generally salts of metals capable of undergoing oxidation/reduction reactions very readily. A typical salt for this purpose is cobalt naphthenate, which undergoes the kind of reactions illustrated in Reactions 4.6 and 4.7. 

Cold curing permits the formation of dual density foam products. We either sequentially inject different formulations or we mold the first foam then mold the second around or on top of it. When making dual density foams, it is important that the first component develop a continuous skin prior to the injection of the second reactive mixture. 

Any method of vulcanising rubber products which proceeds without interruption from start to finish as compared to the method of vulcanising separate batches of products or sections of a product. Continuous vulcanisation processes include the cold curing of proofed cloth, the vulcanisation of belting and flooring, of cables and certain extruded products by either the Liquid Curing Medium, Fluid Bed, Microwave, or Hot Air techniques. 

This term is synonymous with vulcanisation but is generally applied to the factory methods of vulcanising mbber products, e.g., press curing, open steam curing, cold curing. 

Another name for cold cure, named after its discoverer Alexander Parkes. Celluloid, first known as Parkesine was another discovery of Alexander Parkes. 

S2C12, a by-product in the manufacture of carbon tetrachloride from carbon disulphide. Was used, dissolved in solvent naphtha, in the vulcanising of mbber by the cold cure process and the vapour cure process. The process was fraught with health and safety problems and has been superseded by low temperature accelerators and room temperature vulcanising (RTV) systems for silicone and polyurethane. 

The process of treating cold-cured proofings with a weak alkali to neutralise any remaining acid and so prevent subsequent tendering of the fabric. Swelling... 

Weakening of a fabric from any cause, but particularly the weakening of a proofed fabric by the acid resulting from insufficient sweetening, after vulcanisation by the cold cure process. Tensile Strength... 

An obsolescent variation of the cold cure. The articles are vulcanised by exposing them to the vapour of sulphur monochloride in a closed chamber. 

Cold cure" or high resilience PU foams tended to liquify before igniting were developed and gave good results in standard tests such as BS 4735(25) (similar to the discontinued ASTM D1692) but could still burn when used with flammable fabrics in furniture (Table IV). However they have been used most successfully in the UK in combination with flame retarded cotton interliners and fabrics of low flammability e.g. wool, nylon, FR cotton etc. and formed the basis of public area furniture used in the UK since the early 1970 s (Table V). 

Cold cure silicone rubbers and available as pastes. These pastes are mixed with an organometallic catalyst and silicate and cured at room temperature. These are used as adhesives, and as encapsulating materials for electronic components. They are also used for textile coating and in moulds. 

The main limitation to the clinical use of the MAOIs is due to their interaction with amine-containing foods such as cheeses, red wine, beers (including non-alcoholic beers), fermented and processed meat products, yeast products, soya and some vegetables. Some proprietary medicines such as cold cures contain phenylpropanolamine, ephedrine, etc. and will also interact with MAOIs. Such an interaction (termed the "cheese effect"), is attributed to the dramatic rise in blood pressure due to the sudden release of noradrenaline from peripheral sympathetic terminals, an event due to the displacement of noradrenaline from its mtraneuronal vesicles by the primary amine (usually tyramine). Under normal circumstances, any dietary amines would be metabolized by MAO in the wall of the gastrointestinal tract, in the liver, platelets, etc. The occurrence of hypertensive crises, and occasionally strokes, therefore limited the use of the MAOIs, despite their proven clinical efficacy, to the treatment of atypical depression and occasionally panic disorder. 

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