Bisphenol monomer 4,4 -diphenol

Diphenol/thiophenol is one of the most important polymer precursors for synthesis of poly(aryl ethers) or poly-(aryl sulfides) in displacement polymerizations. Commonly used bisphenols are 4,4 -isopropylidene diphenol or bisphenol-A (BPA) due to their low price and easy availability. Other commercial bisphenols have also been reported [7,24,25]. Recently, synthesis of poly(aryl ethers) by the reaction of new bisphenol monomers with activated aromatic dihalides has been reported. The structures of the polymer precursors are described in Table 2. Poly(aryl ether phenylquinoxalines) have been synthesized by Connell et al. [26], by the reaction of bisphenols containing a preformed quinoxaline ring with... 

Synthesis. Five different polyaryl ethers were made from the condensation product, resulting from the reaction of phenol and levulinic acid, commonly referred to as diphenolic acid, and one or more of the following monomers bisphenol A, dichlorodiphenyl sulfone, 2,6-dichloro-benzonitrile, and 4,4 -difluorobenzophenone. The resulting polymers were subsequently methylated such that the common monomer becomes (1) ... 

The first step of this synthesis is to form a bis-imide monomer formed by the reaction of nitrophthalic anhydride and a diamine (see Figure 4.21). The second step of polyetherimide synthesis involves the formation of a bisphenol dianion by treatment of a diphenol with two equivalents of base, followed by... 

Kim et al. [47] prepared three PAEs with pendant -CF3 groups from 2,2 -feiXtrifluoromethyl)-4,4 -dinitro-l,T-biphenyl and bisphenols (BEA, 4,4 -(hexafluoroisopropylidene) diphenol (6F-BPA), and 4,4-biphenol) through meto-activated nucleophilic nitro displacement reaction and investigated their properties. Scheme 2.6 shows the structures of monomers and polymers. 

Industrially, diphenols such as bisphenol A are frequently used in order to increase the stiffness of polymers thanks to their aromatic backbone (Fig. 1.20). However, for biomedical applications diphenols cannot be used as monomers because they are cytotoxic. Tyrosine (2-amino-3-(4-hydroxyphenyl) propanoic acid) is the only major natural nutrient containing an aromatic hydroxyl group. Thus, tyrosine dipeptide (where the terminal amino group and terminal carboxylic group are protected) can be seen as replacing diphenols for biomedical devices. 

Tyrosine is the only major, natural nutrient containing an aromatic hydroxyl group. Derivatives of tyrosine dipeptide can be regarded as diphenols and may be employed as replacements for the industrially used diphenols such as Bisphenol A in the design of medical implant materials (Kigime 1). The observation that aromatic backbone structures can significantly increase the stiffness and mechanical strength of polymers prowded the rationale for the use of tyrosine dipeptides as monomers. 

In this review of the history of polyarylates, only those products of an aromatic dicarlDoxylic acid (or derivative) and a diphenol (or derivative) will be considered. Structurally similar aromatic polyesters based on p-hydroxybenzoic acid have received considerable interest due to the resultant liquid crystalline behavior of these materials. They, however, will not be covered in this paper. The primary polyarylate discussed herein is leased on Bisphenol A (2,2-bis(4-hydroxyphenyl)propane) and tere/iso-phthalic acids. These monomers are large volume commercial products and are utilized in the primary commercial polyarylates available today. 

PEKs with pendant thermolabile substituents allowing for thermal cure were studied by two research groups. Polycondensations involving nucleophilic substitution steps were used in all cases. However, in the first case a thermolabile electrophilic monomer (144a) was used [230], whereas alkine substituted diphenols (144b) served as thermolabile monomers in the second study [231]. Finally, a paper dealing with the grafting of anionically polymerized styrene (145) on a bisphenol-A PEK (146) should be mentioned [232]. 

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