Particulate poly-3-hydroxypropionate and method of precipitation

Particulate poly-3-hydroxypropionate, obtainable by reacting ethylene oxide with carbon monoxide in the presence of a cobalt-containing catalyst system, characterized in that the particulate poly-3-hydroxypropionate comprising a cobalt content of less than 300 ppmw, and a process for the preparation of particulate poly 3-hydroxypropionate comprising the steps of: a) reacting dissolved in a solvent of ethylene oxide with carbon monoxide in the presence of a catalyst system comprising at least a cobalt source, to obtain a solution of poly-3-hydroxypropionate in the solvent; b) precipitation of poly-3-hydroxypropionate from the solution of poly-3-hydroxypropionate in the solvent by adding an antisolvent, wherein the addition takes place under agitation to obtain a suspension of poly-3-hydroxypropionate in a solvent / antisolvent mixture ; c) feeding a gas containing molecular oxygen to the solution or suspension during and / or after the precipitation b); d) separation of poly-3-hydroxypropionate by solid-liquid separation; and e) washing the separated poly-3-hydroxypropionate; characterized in that the particulate poly-3-hydroxypropionate comprising a cobalt content of less than 300 ppmw. The method permits the production of poly-3-hydroxypropionate in a substantially cobalt-free form.