Phase transfer catalyzed polycondensation

Bisphenol-AF-derived poly(carbonate) (2) has been synthesized by the two-phase transfer-catalyzed polycondensation of Bisphenol AF (1) with trichloromethyl chloroformate (TCF) in organic-solvent-aqueous-alkaline solution systems with a variety of quaternary ammonium salts at room temperature (Scheme l).6... 

Triazine containing polysulfides having high molecular weights have been readily synthesized by the phase-transfer catalyzed polycondensation of 6-diethylamino or dibutylamino-l,3,5-triazine-2,4-dithiols with 1,10-dibromodecane in the presence of cetyl trimethyl ammonium bromide in a nitrobenzene-aqueous alkaline solution system <99MI294>. 

A quite different approach to chain-growth condensation polymerization is phase-transfer-catalyzed polycondensation of solid monomer dispersed in an... 

Various types of condensation polymers such as aromatic polysulfonates and polysulfides, aromatic polyethers, aliphatic and aromatic polysulfides, and carbon-carbon chain polymers of high molecular weights by the phase-transfer catalyzed polycondensation fi-om combinations of aromatic disulfonyl chlorides, phosphonic dichlorides, activated aromatic dichlorides, and aliphatic dihalides, withbisphenol, aliphatic and aromatic dithiols, and active ethylene compounds. The two-phase polycondensation was generally carried out in a water-immiscible organic solvent-aqueous alkaline solution system at room temperature. The method of polycondensation offers a highly versatile and convenient synthetic method for a variety of condensation polymers. 

The polycarbonates are prepared by phase-transfer catalyzed polycondensation of activated carbonyloxy derivatives of tertiary, or other reactive diols,20 with simple diols such as bisphenol A (Scheme I). This procedure affords materials with molecular weight Mn= 10-50,000 while only low molecular weight materials resulted from the amine catalyzed condensation of the tertiary diols with the bis-chloroformate of bisphenol A. 

SYNTHESIS OF POLYETHERS BY PHASE-TRANSFER CATALYZED POLYCONDENSATION... 

Phase transfer catalyzed polycondensation was also applicable to the syntheses of aliphatic and aromatic polysulfides. For example, aliphatic polysulfide X from aliphatic dibromide VHI and aliphatic dithiol IX [Eq.(4)],8 aromatic polysulfide XII from activated aromatic dichloride VI and aromatic dithiol XI [Eq.(5)], and another type of polysulfide XIV from activated dichloride Xm and XI [Eq.(6)].10... 

All of these results were already presented at the ACS Houston Meeting on March, 1980.11 12 Since that time, further efforts have been made to synthesize novel condensation polymers by phase transfer catalyzed polycondensation. The present article deals with our recent works on the syntheses of carbon-carbon chain polymers and new types of polysulfides.1 The following abbreviations of phase transfer catalysts have been used throughout this article tetra-methylammonium chloride (TMAC), tetraethylammonium chloride (TEAC), tetrabutylammonium chloride (TBAC), benzyltriethylammonium chloride (BTEAC), cetyltrimethylammonium chloride (CTMAC), cetyltrimethyl-ammonium bromide (CTMAB), benzyltriphenylphosphonium chloride (BTPPC), cetyltributylphosphonium bromide (CTBPB), 15-crown-5 (15-C-5), 18-crown-6 (18-C-6), dibenzo-18-crown-6 (DB-18-C-6), dicyclohexyl-18-crown-6 (DC-18-C-6), dibenzo-24-crown-8 (DB-24-C-8), and dicyclohexyl-24-crown-8 (DC-24-C-8) ... 

The phase transfer catalyzed polycondensation that led to the formation of polymer XVII was first carried out with -butyl cyanoacetate XV and ot, ot -dichloro-p-xylene XVI in a benzene-aqueous alkaline solution system [Eq.(7)]. ... 

An essential feature of this type of polycondensation is that relatively large amounts of the phase transfer catalyst, at least 50 mol%, based on each monomer were required to yield the high molecular weight polymer, as shown in Figure 3. This presents a striking contrast to the fact that only catalytic amounts of the catalyst are necessary in the usual phase transfer catalyzed polycondensation reported previously.12 it may be conveniently e q)lained by the fact that the catalyst is actually occluded in a polymeric mass which is separated during the polymerization. 

The time dependence of inherent viscosity of polymer XVII is shown in Figure 4. The phase transfer catalyzed polycondensation proceeded much more rapidly with BTEAC than that with 18-C-6 at 50°C. 

Previously we reported the syntheses of aliphatic polysulfides with high molecular weights by the phase transfer catalyzed polycondensation of dibromoalkanes with aliphatic dithiols in aqueous potassium hydroxide.8 Sodium sulfide is an attractive monomer for the preparation of polysulfides, since it is readily available and inexpensive. The two-phase polycondensation of dibromooctane XX... 

Phase transfer catalyzed polycondensation [Eq.(11)] provides advantages of the simplicity of reaction and work-up for obtaining condensation polymers, and so this method should enjoy enormous growth over the next few years. 

Yamazaki, N., Imai, Y, Phase Transfer Catalyzed Polycondensation of Bishalo-methyl Aromatic compounds, Polym. J. 1983,15,905. 

A single electron transfer mechanism seems also to best explain the synthesis of poly(thio-l,4-phenylene) from 1,4-dichlorobenzene and sodium sulfide. The mechanism of the halogen displacement phase transfer-catalyzed polycondensation of 4-bromo-2,6-dimethylphenol occurs by a single electron transfer reaction which leads to a telechelic PPO containing one bromophenyloxy and one phenolic chain end of controllable molecular weight. 

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