In recent years several papers describing the application of phase transfer catalysis (PTC) to polymer synthesis have appeared. Polymers prepared by this means include polycarbonates'), polysulfonates2), polypho~phonates~), and polyesters4* 9. During an investigation on the range of applicability of PTC in polymer synthesis we have examined polyether formation from the polycondensation of diphenols with bis(halo-methy1)benzenes. We have concentrated on bis(bromomethy1)benzenes because the bromo derivatives are more reactive than the corresponding chloro compounds. Traditionally, aromatic polyethers are prepared by reaction of the dimetal salt of the diphenol with a dihalide in a polar solvent at relatively high temperatures". As phase transfer catalysed reactions are normally conducted under fairly mild conditions some technical advantage could accrue from synthesising polyethers by this route. N'Guyen and Boileau" have already demonstrated the feasibility of the PTC approach.
Experimental PartMaterials: 4,4'-Isopropylidenediphenol (bisphenol A) (la), 4,4'-disulfonyl diphenol (bisphenol S) (lb), and 4.4'dihydroxybenzophenone (bisphenol K) (lc) were purified by crystallization from glacial acetic acid. (2a), and 1,3-bis(bromo-methy1)bgnzene (3) were purified by repeated crystallization from chloroform.
1,4-Bis(chloromethyl)benzene (Zb), 1 &bis(bromomethyl)benzeneThe following phase transfer catalysts (from Aldrich) were used as received: Aliquat 336 (tricaprylylmethylamm?nium chloride), 18-crown-6 (1,4,7,10,13, ldhexaoxacyclooctadecane), and Kxyptoh [2.2.2] (4;7,13,16,21,24-hexaoxa-1 ,l0-diazabicyclo[8.8.8]hexacosane).The solvents nitrobenzene, chlorobenzene, and dimethyl sulfoxide (DMSO) were Analar grade and were used as received. Anisole, acetophenone, and 1 ,2-dichlorobenzene were distilled before use. Polycondenwtions: In a typical reaction 3,80 mmol of dihalide with 5 mole-% of catalyst was dissolved in 100 ml of solvent and this solution was added to the aqueous phase which comprised 3,80 mmol of diphenol in 10 ml 3 M KOH solution. The mixture was stirred vigorously at 60°C for the required time then cooled and poured into aqueous methanol. The precipitated polymer was washed with water to remove inorganic salts then dried at 40°C i. vac. The polymers were characterised by IR spectroscopy and elemental analysis.
Raults and DiscussionThe IR spectrum of the product from the reaction of bisphenol A (la) with 1,3-bis(bromomethyl)benzene (3) showed characteristic absorption bands at 1 606,
