End-of-life management of fibre-reinforced thermoset composites is challenging due
to the difficult-to-recycle reinforcements and the irreversibly polymerised thermoset
matrix; therefore, researchers proposed the vitrimers as a sustainable alternative
to thermosetting polymers. Although the early results of the material scientists are
promising, the machinability of vitrimers has yet to be explored. Therefore, this
paper aims to present a comparative machinability study of polyimine vitrimer, pentaerythritol-based
epoxy (PER) and polycarbonate polymers through orthogonal machining experiments. Reflecting
on the temperature-dependent properties of vitrimers, the starting temperature of
the cutting tool was varied between room temperature and an elevated temperature above
155 °C. The cutting tool was heated by a 2000-W hot air gun until the surface temperature
of the cutting tool, monitored by a VariocamHD thermographic IR camera (with Jenoptik
IR 1.0/60 LW lens) and checked by a Fluke 51 II thermometer with a type K thermocouple,
was permanently above 155 °C for 5 min. The cutting force was measured by a Kistler
9257B dynamometer, and the machined surface was characterised by a Mitutoyo Surftest
SJ-400 surface roughness tester and Keyence VHX-5000 (with VH-Z20UT VH lens) microscope.
The analysis of variances (ANOVA) results show that the sustainable vitrimer polymer
is an appropriate substitute for thermosetting epoxy polymers, especially at low cutting
temperatures.
