The
design of gradient shape memory polymers (GSMPs) is important
for their sensor or actuator applications, yet challenging. Herein,
we design and prepare GSMP via a gradient aging methodology on nitrile
butadiene rubber composites with sulfur covalent and Zn2+-CN coordination bonding networks. The gradient characteristics of
the GSMP are adequately evaluated by spatially separating them into
equal sections. The aging temperature gradient spatially changes chemical
components of covalent networks, which is verified by FTIR and UV–vis
spectra. SEM and EDS observations show that temperature driven ion
diffusion yields gradient distributions of Zn2+ ions, achieving
a gradient metal–ligand network owing to its high dependence
on metal ions. As a result, GSMPs with gradient covalent and coordination
cross-linking networks are formed. Importantly, a distinct distribution
of glassy temperatures is achieved on this GSMP, leading to its continuous
shape recovery response at different positions during the shape memory
cycle. The finger-shaped temperature sensors are invented to stably
respond over a wide range (9.6–27.0 °C) of thermal triggers
using this GSMP. The possible strategies to improve temperature sensing
properties of the GSMP composites are further proposed. In addition,
our GSMP possesses a timed directional transfer capability. These
findings might be meaningful in providing simple methods of preparing
GSMPs and showing their great potential in temperature sensors and
timed transfer applications.