Polyethers 4,4’-dihydroxybiphenyl

Figure 6. Thermal transition temperatures (T = melting, = isotropization) versus n, the number of methylene units in the polymers containing 4,4 -dihydroxybiphenyl for 1) polyethers ( ) esters (A) T, (A) T. (data from reference 25).

As shown in Scheme 7, the polymerization of bis(4-fluorophenyl) phenyl-phosphine oxide (BFPO) with bisphenols [XIII] was carried out, and thermal properties of the obtained polyethers [XIV-A (ffinh = 0.63 dl/g) and XIV-B i)inh = 0.48 dl/g)] were studied by DSC and TG (12). In this study, 2,2-bis(4-hydroxyphenyl) propane and 4,4 -dihydroxybiphenyl were used as compounds XIII s. 

The goal of this paper is to review our present information on the synthesis and characterization of LC polyethers and copolyethers based on 4,4 -dihydroxy-a-methylstilbene (HMS) and 4,4 -dihydroxybiphenyl (HB) with a, (i)-dibromoalkanes. 

Synthesis of a polyether by phase-transfer catalysis (PTC) under microwave irradiation was investigated by Hurduc et al. [85], who applied 3,3-bis(chlorome-thyI)oxetane (BCMO) and various bisphenols (i.e., bisphenol A, 4,4 -dihydroxya-zobenzene, 4,4 -dihydroxybiphenyl, 4,4 dihydroxybenzophenone, and 4,4 -thi-odiphenyl) to the synthesis (Fig. 19). 

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