This work features the first-time use of poly(trimethylene
terephthalate)
(PTT), a biobased engineering thermoplastic, for fused deposition
modeling (FDM) applications. Additives such as chain extenders (CEs)
and impact modifiers are traditionally used to improve the processability
of polymers for injection molding; as a proof of concept for their
use in FDM, the same strategies were applied to PTT to improve its
printability. The filament processing conditions and printing parameters
were optimized to generate complete, warpage-free samples. The blends
were characterized through physical, thermal, viscoelastic, and morphological
analyses. In the optimal blend (90 wt % PTT, 10 wt % impact modifier,
and 0.5 phr CE), the filament diameter was improved by ∼150%,
the size of the spherulites significantly decreased to 5% of the ∼26
μm spherulite size found in neat PTT, and the melt flow index
decreased to ∼4.7 g/10 min. From this blend, FDM samples with
a high impact performance of ∼61 J/m were obtained, which are
comparable to other conventional FDM thermoplastics. The ability to
print complete and warpage-free samples from this blend suggests a
new filament feedstock material for industrial and home-use FDM applications.
This paper discusses methods to improve hard-to-print polymers and
presents the improved printability of PTT as proof of these methods’
effectiveness.