Characterization of flame-retardant poly(butylene terephthalate) processed by laser sintering

摘要

The effects on powder characteristics and various properties of selective-laser-sintering (SLS) specimens when flame-retardant (FR) materials (10-wt% polypentabromobenzyl acrylate (PPBBA) and 5-wt% antimony trioxide (ATO)) were added to copolymer poly(butylene terephthalate) (cPBT) were evaluated. It was found that acting as a crystal-nucleating agent for cPBT, the ATO powder increases the crystallization temperature of cPBT. It was also found that the combustion characteristics of the powders differ according to whether or not the ATO embeds in the PPBBA. Comparing the flame-retardant IM specimens and the SLS specimens revealed that all the mechanical properties of the SLS specimens tended to be degraded because they contained more porosity than the IM specimens. On the other hand, the SLS specimens showed higher heat-deflection temperatures because they had higher crystallinity than that of the IM specimens. Comparing the various SLS specimens revealed that the specimens in which with ATO was coated on cPBT and PPBBA showed higher mechanical and thermal properties than the specimens with ATO embedded in PPBBA. Furthermore, it was confirmed that the SLS specimens attained a UL94 test rating of grade V0 (with a thickness of 2 mm).