Bisphenol A based epoxy resins

The commercial possibiUties for epoxy resins were first recognized by DeTrey Emres in Switzerland and DeVoe and Raynolds in the United States (1,2). In 1936, DeTrey Emres produced a low melting bisphenol A-based epoxy resin that gave a thermoset composition with phthaUc anhydride. Apphcation of the hardened composition was foreseen in dental products, but initial attempts to market the resin were unsuccessful. The patents were hcensed to CIBA AG of Basel, Switzerland (now CIBA-GEIGY), and in 1946 the first epoxy adhesive was shown at the Swiss Industries Eair and samples of casting resin were offered to the electrical industry. 

Epoxy (Amine-Cured) Bisphenol A-based epoxy resins used for composite fabrication are commonly cured with multifunctional primary amines. For optimum chemical resistance these generally require a heat cure or postcure. The cured resin has good chemical resistance, particularly to basic environments, and can have good temperature resistance. 

Bromide analysis, of water, 26 41 Bromide ions, in development solution, 79 205-206 Bromides, 4 319-330 thorium, 24 763 titanium, 25 54 tungsten, 25 379 uranium, 25 439 Bromimide, 4 299, 319 Brominated additive flame retardants, 77 461-468, 471-473t Brominated Anthanthrone Orange, pigment for plastics, 7 367t Brominated aromatic compounds, 7 7 459 Brominated bisphenol A-based epoxy resins, 70 366... 

Kay and Fust postulated the use of epoxy resin for inhibition of composite propellants [335] and as a consequence, epoxy resins were tried for the first time for the inhibition of HTPB-based composite propellants at Thiokol Corporation, USA. Subsequently, use of the amido-amine hardened modified bisphenol-A-based epoxy resin was reported as inhibitor for fluorocarbon-based composite propellants [336]. Epoxy resins are the most versatile resins for bonding applications for a variety of substrates. This is because of the following characteristics. 

Dowd, R. T., General Chemistry of Bisphenol A Based Epoxy Resins, Chapter 1 in Epoxy Resin Technology, P. F. Bruins, ed., Interscience Publishers, New York, 1968. 

The lower-viscosity grades have an EEW of about 175 and are virtually pure diglycidyl ethers of bisphenol A. They are so pure, however, that they will crystallize on storage. The crystals melt on warming above 40°C, and heating can be used to restore a crystallized resin to its previous form. Special crystallization-free resins systems have been formed by blending low-viscosity DGEBA resins with more conventional bisphenol A-based epoxy resins. 

Liquid undiluted bisphenol A based epoxy resins have average values of n less than 0.2 and viscosities ranging from approximately 7000-15 000 CP at 25 C. 

Figure Z1 The synthesis of a bisphenol A based epoxy resin...

Bisphenol A/bisphenol F epoxy resin blends. It is possible to use blends of bisphenol A and F to achieve superior properties. Many such combinations are commercially available. Such blends significantly reduce the crystallisation tendency which may occur with bisphenol A based epoxy resins when they are subjected to temperature cycling. Such blends also facilitate filler loading and processability. 

Table I. Typical Properties of Bisphenol A-Based Epoxy Resins...

DGEBA diglycidyl ether of bisphenol A-based epoxy resin of epoxy content 0.52 eq./lOO g... 

A study of compatible simultaneous interpenetrating polymer networks (SINs) of diallyl phthalate and (diglycidyl ether of bisphenol A)-based epoxy resin [134],... 

Another case confirms the suspected role of conducting nanoparticles in increased conductivity during and after the reaction in a similar epoxy system. Martin et al. (2005) dispersed CNTs into a bisphenol-A based epoxy resin and reacted it with an amine hardener at SO C. After about 600 s. 

There are many examples in the literature of the structural characterization of polymeric systems by FD-MS. Some of these will be briefly mentioned here. Saito and coworkers in Japan have studied a number of polymers by FD-MS. FD spectra were used to identify various poly(ethylene glycol) and poly(pro-pylene glycol) initiators (water, ethyleneimine, glycerol, sorbitol, sucrose). Structures of bisphenol A-based epoxy resins were elucidated. The degree of methylation in methylol melamine resins was assessed. Various novalak resins (made from phenol, alkylphenols, and epoxidized phenols) were characterized. Styrene polymerized with various initiators and chain transfer agents was studied in some cases deuterium labeling was used to help... 

The functionalization of CNTs through plasma treatment represents a novel and easy approach to scale up towards industrial applications. In more recent works, there were many attempts to fluorinate CNT sidewalls in such manner. The CF4 plasma treatment of SWNT sidewalls was demonstrated to enhance the reactivity of tubes with aliphatic amines.The cure reaction of diglycidyl ether of bisphenol A-based epoxy resin (DGEBA), when reacted with butylamine molecules (BAMs) anchored on to the plasma treated fluorinated SWNTs, was reported. The advantage of this method was that the functionalization could be achieved through a simple approach, which is widely used in thin film technologies. As covalently modified CNTs with fluorine groups offer the opportunity for chemical interactions with the amine systems, it was recently demonstrated that this... 

Chem. Desap. Elastomer-modified bisphenol A-based epoxy resin aq. disp. 

Chem. Descr rp. Bisphenol A-based epoxy resin Uses Vehide or binder in high-performance industrial baking surf, coatings, appliance primers, metal furniture finishes, wire coatings, powd. coating food pkg. adhesives, coatings, paper, dosures with s ing gaskets for tood containers... 

Chem. Descrip. Bisphenol A-based epoxy resin contg. 10% Modaflow (flo control, anticratering agent)... 

Mesua ferrea L. seed oil-based poly(urethane ester) and poly(urethane amide) resins with an NCO/OH ratio of 0.5 are modified by commercially available bisphenol-A based epoxy resin and partially butylated ME resin... 

High molecular weight liquid epoxy resins from modified vegetable oils such as epoxidised soybean, rapeseed, linseed and sunflower oils, as well as from hydroxylated soybean and rapeseed oils have also been prepared. Reactions of (i) epoxidised oils, with bisphenol-A and (ii) bisphenol-A-based epoxy resin with hydroxylated natural oils in the presence of different catalysts such as LiCl, 2-methylimidazole, triphenylphosphine and triethanolamine at 130-160 C (depending on the catalyst type) under nitrogen, produce the required epoxy resins as shown in Rg. 7.7. ... 

P. Czub, Synthesis of high-molecular-weight epoxy resins from modified natural oils and bisphenol A or bisphenol A-based epoxy resins , Polym Adv Technol, 2009,20,194-208. 

It has been found that Mesua ferrea L. seed oil-based thermoplastic hyperbranched polyurethane (HBPU) of the monoglyceride of the oil, PCL (M = 3000 g moT ), 2,4/2,6-toluene diisocyanate and glycerol with 30% hard segment (NCO/OH = 0.96), exhibit thermoresponsive shape memory properties. The shape recovery (88,91 and 95%) and shape retention (70, 75 and 80%) are also found to be different at different temperatures (50, 60 and 70°C respectively). Bisphenol-A-based epoxy resin modified... 

Fig. 3. Dielectric permittivities of a non-filled Bisphenol-A based epoxy resin (C) and its composite filled with 60 wt% wollastonite (C/W, left) and of a non-filled cycloaliphatic epoxy resin (B) and its composites filled with 60 wt% wollastonite (B/W) and quartz (B/Q, right). The high-temperature, low frequency polarization process is most probably due to the matrix/electrode interface in the case of resin C, while it is related to the matrix/filler interface in the case of resin B. (After Ref. [6]).

The incorporation of 5 % organically modified sepiolite, which is a microcrystalline-hydrated magnesium silicate, in a bisphenol A-based epoxy resin has no significant effect over the thermal stability of the epoxy resin, due to the poor dispersion of the clay and poor diffusion of the resin between fibres [69]. The effect of attapulgite (magnesium aluminium phyllosilicate) over the thermal properties of hyperbranched polyimides was studied. The presence of this silicate in the nanocomposites significantly improved the thermal stability of the neat polyimide [70]. 

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