SYNTHESIS OF POLYMERS WITH PENDANT HYDROXYL-GROUPS BY POLYADDITION OFBIS(OXETANE)S WITH DITHIOLS

Addition reaction of (3-methyl-3-oxetanyl)methyl acetate (MOMA) with b is(4-mercaptophenyl) sulfide (BMPS) was examined in certain organic so lvents. When the reaction of MOMA with BNLPS was performed without any catalyst in hexamethylphosphoric triamide (HMPA) and N-methyl-2-pyrro lidone (NMP) at 130 degrees C for 24 h, conversions of the correspondi ng adduct were 96 and 36%, respectively, which was confirmed by H-1-NM R spectra. On the other hand, when the reaction was carried out using tetraphenylphosphonium bromide (TPPB) as a catalyst under the same con ditions, conversions of the adduct were 96 and 81% in HMPA and NMP, re spectively. This result shows that although the addition reaction of o xetane compound with aromatic dithiol proceeds without any catalyst in HMPA, the reaction was strongly enhanced by adding TPPB in NMP. On th e basis of the above results, polyadditions of bis((3-methyl-8-oxetany l)methyl) terephthalate (BMOT) and bis((3-ethyl-3-oxetanyl)methyl) ter ephthalate with BMPS were performed using TPPB as the catalyst in NMP at 130 degrees C for 24 h. As a result, the corresponding high molecul ar weight polymers 1 (M-n = 22,400) and 2 (M-n = 12,800) with pendant primary hydroxyl groups were obtained in 83 and 89% yields without any gel products, respectively. Furthermore, a low molecular weight oligo mer was obtained from the polyaddition of BMOT with aliphatic dithiol, bis(mercaptomethyl)benzene, under the same reaction conditions. The c atalytic activity on the polyaddition of BMOT with BMPS was also exami ned, and it was found that thermally stable TPPB and crown ether compl exes at the reaction temperature (130 degrees C) have higher catalytic activity than tetrabutylammonium bromide and tetrabutylphosphonium br omide to produce polymer I with high molecular weight. (C) 1998 John W iley & Sons, Inc.