Abstract: This invention relates to a process for the preparation of aromatic polyester(s) having an intrinsic viscosity greater than 0.4 dL/g in chloroform at 30.degree. C. which comprises (a) reacting diarylesters of tere and isophthalic acid(s) and dihydric phenol(s) in the melt phase in an inert atmosphere in the presence of a catalyst selected from alkoxides of Group IV B metals and derivatives of Group IV A metals and in the presence of an organic solvent at a temperature in the range of 100.degree.-300.degree. C. to form a prepolymer having intrinsic viscosity in the range of 0.1 to 0.3 dL/g in chloroform at 30.degree. C. (b) purifying the prepolymer using conventional solvent extraction methods and (c) Polycondensing the purified prepolymer at a temperature in the range of 300.degree.-350.degree. C. in presence of a catalyst selected from alkoxides of Group IVB metals and derivatives of Group IVA metals under reduced pressure.

Abstract: The invention discloses an improved process for the preparation of aryl polycarbonates. The process involves reacting aryl carbonate and dihydric phenol in the melt phase with a catalyst belonging to the class of quaternary ammonium bioxyanions having the general formula: ##STR1## Wherein `X` represents a carboxylate or a phenolate group or a mixture thereof and `R` represents alkyl or aryl.

Abstract: Disclosed are reactive anionic initiators of the general formula [ArCHR.sub.1 R.sub.2 N(R.sub.3 R.sub.4 R.sub.5 R.sub.6 ] wherein Ar=phenyl, substituted phenyl, or a heterocyclic compound, R.sub.1 =R.sub.2 =H, ester, cyano, alkyl, aryl, 1,3-oxazoline, N,N-dimethyl amide and other similar alpha activating groups, or combination of them, or one of R.sub.1 or R.sub.2 together with Ar, where Ar is a phenyl or substituted phenyl, is a nitrogen atom containing heterocyclic compound and the other being a nitrile group, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 may be same or different and represent substituted alkyl, cycloalkyl, arylalkyl or aryl or to of the R.sub.3, R.sub.4, R.sub.5 and R.sub.6 together with nitrogen atom form a heterocycle with the condition that the sum of all carbon atoms of all R.sub.3, R.sub.4, R.sub.5 and R.sub.6 is from 12 to 50 and no more than one of the R.sub.3, R.sub.4, R.sub.5 and R.sub.6 is an aryl derivative.

Abstract: The invention disclosed is an improved process for the preparation of high molecular weight poly(arylcarbonate), the molecular weight ranging from 45,000-60,000 (corresponding to n.sub.inh 0.8 to 1.0) The process involves heating in a controlled manner, a BPA-polycarbonate oligomer in the presence of a catalyst selected from alkali metal aryl acid, alkali metal borohydrial and a quarternary ammonium salt of bioxiyanion derived from a carboxylic acid poly(arylcarbonate)s of high molecular weight produced by the process of present invention show enhanced crystallinity.

Abstract: An improved process is disclosed for the preparation of nitrile group containing polymers which comprises reacting a nitrile group containing vinyl monomer with an initiator of the general formula [ArCR.sub.1 R.sub.2 ].crclbar.[N(R.sub.3 R.sub.4 R.sub.5 R.sub.6)].sym. wherein Ar=phenyl, substituted phenyl or a heterocyclic compound, R.sub.1 =R.sub.2 =H, ester, cyano, alkyl, aryl, 1,3-oxazoline, N,N-dimethyl amide and other similar alpha activating groups, or combination of them, or one of R.sub.1 or R.sub.2 together with Ar, where Ar is phenyl or substituted phenyl, is a nitrogen atom containing heterocyclic compound and the other being a nitrile group, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 may be same or different and represent substituted alkyl, cycloalkyl, arylalkyl or aryl or two of the R.sub.3, R.sub.4, R.sub.5 and R.sub.6 together with nitrogen atom form a heterocycle with the condition that the sum of all carbon atoms or all R.sub.3, R.sub.4, R.sub.5 and R.sub.