Polycondensations of aliphatic dicarboxylic acids (ADAs) with 1,4-butane or 1,6-hexane diol were conducted in bulk at 80 or 100 °C. Temperature and monomer/catalyst ratio were varied. With bismuth triflate, Bi(OTf) 3 , as catalyst, number average molecular weights (M n 's, uncorrected SEC data) up to 30 000 Da were obtained. Analogous polycondensations were performed with the triflates of sodium, magnesium, aluminum, zinc, tin(II), scandium, and hafnium, but the highest M n values were achieved with Bi(OTf) 3 . Polycondensations and model experiments proved that most triflates catalyzed the formation of tetrahydrofuran from 1,4-butane diol above 100 °C. Therefore, polycondensations of 1,4-butane diol required temperatures e100 °C. Polycondensations of 1,4-butene diol or 1,4-butyne diol were unsuccessful, because of side reactions. All polycondensations involved rapid equilibrations, and the content of cyclic oligo-and polyesters increased with the conversion.

The kinetics associated with the reaction of aromatic and aliphatic diamines with phthalic anhydride in glacial acetic acid was studied. This model system was intended to simulate the synthesis of polyimides from diamines and dianhydrides in molten benzoic acid. The reaction proceeds in two discrete steps, the first acylation occurs by the reaction of the diamine with phthalic anhydride followed by cy-clodehydration of the corresponding bis-(o-carboxyamides). The focus of the work was on the influence of chemical composition and basicity of the diamines on the kinetics. Kinetic and thermodynamic characteristics of model reactions were determined. It was established that acylation of aromatic and aliphatic diamines in acid medium proceeds as a reversible second-order reaction catalyzed by acid medium. On the basis of kinetic data obtained, an explanation is given for the observed phenomenon of reactivity leveling of diamines regardless of the basicity.

The one-pot, high temperature, catalytic synthesis of polyetherimides (PEIs) in molten benzoic acid was investigated. The synthesis was conducted using the AB monomers, 4-aminophenoxy phthalic acid (IIa) and 3-aminophenoxy phthalic acid (IIb). Both Homo and co-PEIs with different ratios of substituted AB IIa and IIb were prepared and characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry and wide angle X-ray diffraction. The solubility of the polymers in a variety of solvents was also investigated. Homo-poly-lib is an amorphous thermoplastic that is soluble in CHC13 DMS8 and amide-type solvents. Homo-poly-IIa has a locally ordered structure and is insoluble. Properties of the IIa/IIb copolymers depend strongly on their composition. When the IIa/Hlb ratio is 30: 70 or less, co-PEIs behave as thermoplastic substances soluble in chloroform. At an IIa/lIb ratio in the starting mixture of 40: 60 or higher, the properties of co-PEIs are similar to that of poly-IIa.

Polyesters of butyne‐1,4‐diol (ByD) and aliphatic dicarboxylic acids (ADAs) were prepared in three different ways. Method I is based on the transesterification of ByD with the dimethyl esters of ADAs in bulk. Although catalyst and temperature were varied, only oligomers were obtained, because even at 220 °C the conversions were far from complete. Higher molar masses resulted from method II, the acid‐catalyzed polycondensation of ByD with sebacic acid, but this method yielded a high fraction of ether groups. The best results were obtained from method III, which consisted of pyridine‐catalyzed polycondensations of ByD and various ADA dichlorides at 0–20 °C. SEC measurements yielded corrected number average molecular weights ($\overline M _{\rm n}$) up to 20 000 Da. The success of this method depended largely on the excess of the ADA dichloride in the feed ratio. MALDI‐TOF mass spectrometry evidenced that under optimized reaction conditions the chain‐growth was mainly limited by cyclization. With the exception of the polysuccinate, all polyesters were rapidly crystallized materials with melting temperatures in the range of 50–90 °C.