Chemical Properties
Powder
Uses
4,4'-biphenol be used intermediate liquid crystal polymers raw materials. Synthetic polymers, due to its excellent heat resistance, it is used as polyester, urethane modified monomer, polycarbonate, polysulfone, and epoxy resin, for the manufacture of an excellent engineering plastics and composite materials. Antioxidant antioxidants for rubber and plastics. Dye intermediates or petroleum products stabilizer.
Uses
Biphenol is an intermediate used in the manufacture of thermoplastics such as liquid crystalline polymers (LCP), polyesters, polycarbonates and polysulfones.
Uses
Intermediates of Liquid Crystals
Definition
ChEBI: A member of the class of hydroxybiphenyls that is biphenyl with hydroxy groups at positions 4 and 4'.
Production Methods
4,4'-Biphenol can be
synthesized in excellent yields by debutylation
of 3,3',5,5'-tetra-tert-butyl-4,4'-dihydroxybiphenyl. Other production processes are the
alkaline fusion of 4,4'-biphenyldisulfonic acid,
the boil down of benzidinebisdiazonium salts, and the decarboxylation of 4,4'-dihydroxybiphenyl-2-carboxylic acid. Symmetrically alkylated 4,4'-dihydroxybiphenyls such as 4,4'-dihydroxy-2,2',3,3',5,5',6,6'-hexamethylbiphenyl are preferably obtained by the
oxidative coupling of the corresponding substituted monophenols. Here, diphenoquinones are generally formed in the first step
which must be reduced. Phenol itself always
gives isomeric mixtures of dihydroxybiphenyls
on coupling with various oxidants. These
mixtures are also formed by alkaline fusion of
4,4'-dihydroxybiphenylsulfone.
Flammability and Explosibility
Notclassified
Safety Profile
Poison by intraperitoneal route.Moderately toxic by skin contact. Mildly toxic byingestion. Human mutation data reported. When heated todecomposition it emits acrid smoke and irritating fumes.
Purification Methods
Recrystallise the biphenol from aqueous EtOH preferably under N2 to avoid oxidation to the extended qiunone. It is characterized as the dimethyl derivative (4,4’-dimethoxybiphenyl) from which it is prepared by demethylation. The dimethoxy derivative has m 176.5-177o (from AcOH, EtOH, hexane or *C6H6) and sublimes in vacuo. [Williamson & Rodebush J Am Chem Soc 63 3019 1941, Beilstein 6 I 485, 6 II 962, 6 III 6389, 6 IV 6651.]
