Solid state polycondensation in dispersed medium of 11-aminoundecanoic acid

The polycondensation of 11-aminoundecanoic acid was carried out in the soli d state in dispersed medium: Decalin which is an inert saturated cyclic hyd rocarbon and does not react with the monomer and the condensation by produc t, water, was added to the monomer. In order to avoid a coagulation of the reaction mixture, an original strategy was developed using a liquid-solid d ispersion instead of a liquid-liquid dispersion as described in the few stu dies reported in the literature for the polycondensation of this monomer. A liquid-liquid suspension step was used at the early beginning of the react ion in order to melt, disperse and break the crystallinity of the monomer, then, the liquid droplets were solidified by cooling. During the polyconden sation, the temperature was raised in successive steps in order to maintain the particles in the solid state. With a convenient treatment, it was poss ible to obtain a polymer powder with a defined particle size distribution a nd to reach fairly high molecular weights.