Bisphenol A -based

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. 

The multiepoxy functionality of the epoxy novolaks (2.2 to >5 epoxy groups per molecule) (3) produce more tightly cross-linked cured systems having improved elevated temperature performance and chemical resistance than the difunctional bisphenol A-based resins. 

C—S—C) in the main chain. The new polyethers prepared either by new heteroarylene activated or by aromatic activated systems have good melt processability. The thermal stability and glass transition temperature of bisphenol-A based new polymers are shown in Table 10. 

Robeson and Matzner were the first to report the synthesis of the sulfonation of DCDPS.205 This work makes it possible to synthesize sulfonated poly(arylene ether sulfone) with well-controlled structures. Ueda et al. used this monomer (Scheme 6.27) as a comonomer of DCDPS to react with bisphenol A and high-molecular-weight bisphenol-A-based copolymers with up to 30 mol % sulfonation achieved.206 Biphenol-based copolymers with up to 100 mol % sulfonation were recently reported by Wang et al.207... 

Hedrick et al. reported imide aryl ether ketone segmented block copolymers.228 The block copolymers were prepared via a two-step process. Both a bisphenol-A-based amorphous block and a semicrystalline block were prepared from a soluble and amorphous ketimine precursor. The blocks of poly(arylene ether ether ketone) oligomers with Mn range of 6000-12,000 g/mol were coreacted with 4,4,-oxydianiline (ODA) and pyromellitic dianhydride (PMDA) diethyl ester diacyl chloride in NMP in the presence of A - me thy 1 morphi 1 i nc. Clear films with high moduli by solution casting and followed by curing were obtained. Multiphase morphologies were observed in both cases. 

Hexa-fluorobisphenol A (HFBPA) based polysulfone and poly(arylene ether phosphine oxide) were prepared by nucleophilic aromatic substitution similar to that of bisphenol-A-based polysulfone and poly(arylene ether phosphine oxide).11... 

Figure 7.38 Epoxy structures (1) bisphenol-A-based epoxy, (2) brominated bisphenol-A-based epoxy, and (3) siloxane epoxy.

A difunctional bisphenol-A-based benzoxazine has been synthesized and characterized by GPC and 1II NMR (Fig. 7.39). A small of amount of dimers and oligomers also formed. Thermal crosslinking of bisphenol-A benzoxazine containing dimers and oligomers resulted in networks with relatively high Tgs. Dynamic mechanical analysis of the network showed a peak of tan 8 at approximately 185°C. 

Bis(4-hydroxyphenyl)-lV-phenyl-l,2-naphthalimide, 354, 355 4,4 -Bis(4-hydroxyphenyl)pentanoic acid (BHPA), 355, 356 Bisnitroimides, 346 Bisphenol-A, 112 Bisphenol-A-based benzoxazines... 

Bisphenol-A-based poly(ether imide), 346 Bisphenol-A benzoxazine crosslinking reactions, 416... 

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. 

Figure 20.1 Chemical structure of bisphenol A based polycarbonate...

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... 

Sulfur dioxide was the major volatile product and was used as a probe to correlate the radiation resistance with polymer structure. The use of biphenol in the polymer reduced G(SO ) by 60% compared with bisphenol A based systems (Bis-A PSF). Surprisingly, the isopro-pylidene group was shown to be remarkably radiation resistant. The ultimate tensile strain decreased with dose for all polysulfones investigated and the rate of decrease correlated well with the order of radiation resistance determined from volatile product measurements. The fracture toughness (K ) of Bis-A PSF also decreased with irradiation dose, but the biphenol based system maintained its original ductility. 

After final chromatographic purification, samples of the AT-systems were cured in air at 288°C (550°F) for eight hours. Samples chosen for curing included pure monomers, monomer/oligomer mixtures produced by the stoichiometry outlined In the previous section, and In one case (the bisphenol-A based resin) pure oligomer. This set of samples was selected to provide data showing the effect of oligomer concentration on thermomechanical properties. 

The use of maleic anhydride as a compatiblizer between wood particles and bisphenol A-based polyesters resins has been investigated (Han etal., 1991). In this study, the MA was added directly to the composition of woody matrix filler and resin rather than by pre-modification of the wood. It was found that composite properties were improved by addition of MA, probably due to esterification of the wood occurring during the kneading process. The modification of sawdust using maleic anhydride has been performed in order to provide a compatible filler for polyester resins (Marcovich etal., 1996). Modification was performed at room temperature using a solution of maleic anhydride in acetone, in some cases catalysed with sulphuric acid. It was claimed that bonding occurred under these mild conditions from IR spectroscopic evidence only. 

Polycarbonates can be included in this category. In fact, the bisphenol A-based polycarbonates are one of the most deeply studied classes of polymers in relation to its photochemical stability. To date, it is well established that the photochemical processes occurring in these polymers are wavelength dependent [226-230]. When photolyzed with > 300 nm, several radical and oxidative reactions take place, whereas with < 300 nm, the PFR as shown in Scheme 76 becomes important. Analogous dual photochemistry has been shown recently for trimethylclohexane-polycarbonate [231]. 

Monitoring of the PFR can be made spectroscopically because the photoproducts have well-defined absorbtion bands in the UV-visible and infrared (IR) ranges [232]. Fluorescence spectroscopy allows the early detection of phenyl salicylate-type products in the photolysis of bisphenol A-based polycarbonates due to the characteristic emission of this chromophore around 470 nm [233]. 

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. 

In addition to sulfone, phenyl units, and ether moieties, the main backbone of polysulfones can contain a number of other connecting units. The most notable such connecting group is the isopropylidene linkage which is part of the repeat unit of the well-known bisphenol A-based polysulfone. It is difficult to clearly describe the chemical makeup of polysulfones without reference to the chemistry used to synthesize them. There are several routes for the synthesis of polysulfones, but the one which has proved to be most practical and versatile over the years is by aromatic nucleophilic substitution. This polycondensation route is based on reaction of essentially equimolar quantities of 4,4,-dihalodiphenylsulfone (usually dichlorodiphenylsulfone (DCDPS)) with a bisphenol in the presence of base thereby forming the aromatic ether bonds and eliminating an alkali salt as a by-product. This route is employed almost exclusively for the manufacture of polysulfones on a commercial scale. 

Soh, N., T. Watanabe, Y. Asano, et al. 2003. Indirect competitive immunoassay for bisphenol A, based on a surface plasmon resonance sensor. Sens. Mater. 15 423 438. 

Park, J.W., S. Kurosawa, H. Aizawa, et al. 2006. Piezoelectric immunosensor for bisphenol A based on signal enhancing step with 2-methacrolyloxyethyl phosphorylcholine polymeric nanoparticle. Analyst 131 155-162. 

Kulesza, K. Pielichowski, K. Thermal decomposition of bisphenol A-based polyetherurethanes blown with pentane Part II—Influence of the novel NaH2P04/NaHS04 flame retardant system. J. Anal. Appl. Pyrolysis 2006, 76, 249-253. 

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