Chemical recycling of additively manufactured objects

A method of recycling additively manufactured object into a reusable thermoplastic polymer, comprising:

• (a) providing at least one additively manufactured object produced by stereolithography from a dual cure resin, the object comprising a semi-interpenetrating network of (i) a light polymerized polymer, and (ii) a heat polymerized polymer;
• (b) comminuting the object to produce a particulate material therefrom;
• (c) contacting the particulate material to a polar, aprotic solvent for a time and at a temperature sufficient to extract the heat polymerized polymer from the particulate material into said solvent, leaving residual particulate material comprising said light polymerized polymer in solid form, wherein the dry weight of said residual particulate material is from 40% to 70% of the dry weight of the particulate material prior to the contacting step;
• (d) separating the residual particulate material from said solvent;
• and then
• (e) separating the heat polymerized polymer from said solvent to provide a reusable thermoplastic polymer material in solid form.