Acid curing, application

The application of the branching theories to acid curing was rather successful the discovery of the relative Importance of the transesterification following the epoxy-carboxyl addition initiated the theoretical treatment of branching. The prediction was that... 

In this example radiation euring is eompared with several other eoating teehnologies, sueh as solvent-based two-eomponent polyurethane, acid curing, nitrocellulose and water-based coatings. In the application discussed here, a specific customer use was defined as performance application of 1,000 wooden front doors. 

Crain, P.F. and McGloskey, J.A. (1998) Applications of mass spectrometry to the characterization of oligonucleotides and nucleic acids. Cure. Opin. 

One-part. Within these, some liberate acetic acid during cure - these are not appropriate for corrosion sensitive applications. Others are described as neutral cure, Indicating the absence of acid cure products. 

Uses Pickling and anchoring agent for the application of paints flexibilizer in inks hardener for acid-curing paints... 

The presence of the unsaturated substituent along this polyester backbone gives this polymer crosslinking possibilities through a secondary reaction of the double bond. These polymers are used in paints, varnishes, and lacquers, where the ultimate cross-linked product results from the oxidation of the double bond as the coating cures. A cross-linked polyester could also result from reaction (5.J) without the unsaturated carboxylic acid, but the latter would produce a gel in which the entire reaction mass solidified and is not as well suited to coatings applications as the polymer that crosslinks upon drying. ... 

The resins are hardened in situ by mixing with an acidic substance just before application. A typical curing system would be four parts of toluene-p-sulphonic acid per 100 parts resin. The curing may take place at room temperature if the resin is in a bulk form but elevated temperature cures will often be necessary when the material is being used in thin films or coatings. 

Resoles are usually those phenolics made under alkaline conditions with an excess of aldehyde. The name denotes a phenol alcohol, which is the dominant species in most resoles. The most common catalyst is sodium hydroxide, though lithium, potassium, magnesium, calcium, strontium, and barium hydroxides or oxides are also frequently used. Amine catalysis is also common. Occasionally, a Lewis acid salt, such as zinc acetate or tin chloride will be used to achieve some special property. Due to inclusion of excess aldehyde, resoles are capable of curing without addition of methylene donors. Although cure accelerators are available, it is common to cure resoles by application of heat alone. 

Homogeneous catalysis by lin compounds is also of great indusirial importance. The use of SnCU as a Friedel-Crafts catalyst for homogeneous acylation, alkylation and cyclizaiion reactions has been known for many decades. The most commonly used industrial homogeneous tin catalysis, however, are the Sn(ll) salts of organic acids (e.g. acetate, oxalate, oleale, stearate and ocToate) for the curing of silicone elasloniers and, more importantly, for the production of polyurethane foams. World consumption of tin catalysts for the.se Iasi applications alone is over 1000 tonnes pa. 

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