1 research outputs found
Vat Photopolymerization of Synthetic Isoprene Rubber Latexes
Isoprene-based elastomers comprise a large percentage
of the traditional
elastomer market with broad technological impact; however, the challenge
of three-dimensional (3D) printing intricate geometries using synthetic
isoprene rubbers remains elusive. This manuscript reports synthetic
isoprene rubber (SIR) latexes as a precursor for the unprecedented
3D printing of high-molecular-weight isoprene-based elastomers with
vat photopolymerization (VP). Dispersed SIR latex particles at 900
nm mitigate entanglement of high-molecular-weight SIR and thus provide
low viscosities, which are aligned with viscosity requirements (<10
Pa·s) for VP. The incorporation of reactive monomers, i.e., 1-vinyl-2-pyrrolidone
(NVP) and poly(ethylene glycol) diacrylate (PEGDA), into the aqueous
phase enables the rapid photopolymerization forming a hydrogel scaffold
embedded with SIR particles. Subsequent thermal postprocessing of
the photocured hydrogel green bodies promotes SIR particle coalescence
through the photogenerated scaffold resulting in a semi-interpenetrating
network (sIPN) that exhibits isotropic shrinkage while preserving
structural fidelity. Variation in the scaffold concentration tuned
the elastomeric properties of the photocured SIR with elongations
at break ranging from 94 to 682%. The resulting elastomers exhibit
multiphase morphologies and elastomeric properties for a variety of
3D geometric structures