The present disclosure is directed to a thermoplastic polymer for additive manufacturing, wherein the thermoplastic polymer is derived from a chlorinated monomer unit, wherein the thermoplastic polymer has a melt flow rate (MFR) suitable for additive manufacturing. The present disclosure is also directed to a method of making a 3D product formed by additive manufacturing, wherein the 3D product comprises a thermoplastic polymer derived from a chlorinated monomer unit or a thermoplastic composition comprising at least one thermoplastic polymer derived from a chlorinated monomer unit; and at least one stabiliser, wherein the thermoplastic polymer or composition has a MFR suitable for additive manufacturing.