Hardening organic

Hanabusa. K. Matsumoto, Y. Miki. T. Koyama, T. Shirai. H. Cyclo(dipeptide)s as low-molecular-mass gelling agents to harden organic fluids. J. Chem. Soc., Chem. Commun. 1994, 1401-1402. 

Vinyl ester resins (epoxy diacrylates) are used by the glass-fibre-reinforcement industry for products that are resistant to chemicals and corrosion. They are epoxy di(meth)acrylates (P-hydroxyester acrylates) that are usually obtained by reacting epoxy resins of glycidyl derivatives with (meth)acrylic acid. They can also be manufactured from bisphenol A and glycidyl (meth) acrylates (Kanerva et al. 1986 Kanerva et al. 1989 Jolanki 1991). Acrylates based on bisphenol A or epoxy resin can be polymerised by electron beams, ultraviolet light, and also by the addition of various peroxides (Jolanki et al. 1995). The same cross-linker (styrene), hardeners (organic peroxides) and accelerators (cobalt) as for unsaturated polyester resin are used in composite epoxy acrylates (Rolston 1980). 

Allergic contact dermatitis can be caused by epoxyresin compounds (Tarvainen et al. 1995), UP resin (Liden et al. 1984 Tarvainen et al. 1993a, 1995) and chemicals used as accelerators (cobalt) (Bourne and Milner 1963 Tarvainen et al. 1993b, 1995) or hardeners (organic peroxides) (Bourne and Milner 1963), as well as by p-tert-butylphenol formaldehyde resin (Tarvainen et al. 1993b) and various woods (Hausen and Adams 1990). Natural rubber latex in protective gloves has caused occupational contact urticaria (Tarvainen et al. 1993b). 

Plastics, textile dyes, ink Plasticizers, insecticides Dyes, pigments, metal hardening Organic chemical synthesis Lubricants, pesticides e.g., Amiton)... 

Retarders and Accelerators. Materials that control hardening of cement may be either organic or inorganic. Retarders are often incorporated in oil well cementing and hot-weather concrete appHcations, whereas accelerators may be useful for cold-weather concrete appHcations in which higher rates of reactivity are desirable. In most cases, these admixtures are used in low concentrations, suggesting that they act by adsorption. 

Sohd rocket propellants represent a very special case of a particulate composite ia which inorganic propellant particles, about 75% by volume, are bound ia an organic matrix such as polyurethane. An essential requirement is that the composite be uniform to promote a steady burning reaction (1). Further examples of particulate composites are those with metal matrices and iaclude cermets, which consist of ceramic particles ia a metal matrix, and dispersion hardened alloys, ia which the particles may be metal oxides or intermetallic compounds with smaller diameters and lower volume fractions than those ia cermets (1). The general nature of particulate reinforcement is such that the resulting composite material is macroscopicaHy isotropic. 

Cement and Concrete Concrete is an aggregate of inert reinforcing particles in an amorphous matrix of hardened cement paste. Concrete made of portland cement has limited resistance to acids and bases and will fail mechanically following absorption of crystalforming solutions such as brines and various organics. Concretes made of corrosion-resistant cements (such as calcium aluminate) can be selected for specific chemical exposures. 

Material used to activate resins to promote hardening. For polyesters, organic peroxides are used primarily. For epoxies, amines and anhydrides are used. 

Harden T.C. Imeson, Detection and Identification of Trace Quantities of Organic Vapors in the Atmosphere by Ion Cluster Mass Spectrometry and the Ionization Detector System ,... 

The martensitic alloys contain 12 to 20 percent chromium with controlled amounts of carbon and other additives. Type 410 is a typical member of this group. These alloys can be hardened by heat treatment, which can increase tensile strength from 550 to 1380 MPa (80,000 to 200,000 Ibf/in ). Corrosion resistance is inferior to that of austenitic stainless steels, and martensitic steels are generally used in mildly corrosive environments (atmospheric, freshwater, and organic exposures). In the hardened condition, these materials are very susceptible to hydrogen embrittlement. 

---