PREPARATION OF POLY(BUTYLENE TEREPH POWDERS BY MELT EXTRUSION WITH COPOLYMER ADDITIVES

We report a process for preparing poly(butylene terephthalate) (PBT) powders of diameter smaller than 100 m in quantitative yield using amphiphilic block copolymer phase inversion process. 1 Poly(benzyl acrylate)-based block copolymers of controlled M composition were prepared by RAFT polymerization for making PBT powders were evaluated. For several copolymers of the series, SEM and DLS analysis confirmed that monodisperse PBT particles with spherical morphology were ob (Fig. 1). Experimental results were in good agreement with for binary mixtures of polymers. It was shown that the viscosity ratio between the two p the main factor controlling the average size of PBT drop formed by the additive. The average diameter of PBT particles μm and increased with the viscosity ratio between the two phases the PBT particle size and some structural parameters of the block copolymer additive, e.g. its hydrophilic-lipophilic balance. An increase of the weight fraction of the hydrophilic block block copolymer led to particles of smaller diameter.