Thesemibatchemulsifier-freeemulsioncopolymerizationofmethylmethacrylate(MMA)andbutylacrylate(BA)inthepresenceof2-hydroxyethylmethacrylate(HEMA)initiatedbyK2S2O8(PSP)wasstudied.Thelatexparticlescanmaintainanappreciablestabilityduringtheemulsifier-freeemulsioncopolymerizationofMMAandBAinthepresenceofHEMA.Theaverageparticlediameterincreasewithanincreaseoftotalsolidscontent,HEMAcontent,PSPcontent,ionicstrengthofthesystemandmonomerfeedrate,anddecreasewiththemonomerfeedrationfrom3/1(MMA/BA:molarration).to1/3.ThestabilityofthisreactionsystemisimprovedbyaddingHEMAasnonioniccomonomer,Highsolidscontent(50%)latexwithmonodisperseparticlecanbeobtainedusingthisprocess.