A Modified PBT for Fused Deposition Modeling in 3D Printing

Modified poly(butylene terephalate) (poly(butylene terephalate-co-isophthalate-co-sebacate) (PBTIS)) were prepared for fused deposition modeling (FDM) in 3D printing by direct esterification and subsequent polycondensation using terephthalic acid (PTA),isophthalic acid (PIA),sebacic acid (SA) and 1,4-butanediol (BDO). The thermal,rheological and mechanical properties of PBTIS were investigated by ¹H-NMR spectroscopy,Gel Permeation Chromatography (GPC),Differential Scanning Calorimetry (DSC),brookfield viscometer and melt indexer,electronic tensile testing machine and impact testing machine.Results showed that when n(PTA):n(PIA) was 7:3 and the mole fraction of SA was 3%-5%,PBTIS had good melting point and excellent mechanical properties such as tensile strength,flexural strength and notched impact strength. Then the samples of PBTIS were changed into filaments by a desktop drawing machine and printed using a 3D printer,which could be 3D printed fluently.