Liquid
crystalline elastomers (LCEs) are functional materials whose
stimuli response is strongly influenced by the composition and structure
of the polymer network. LCEs are commonly fabricated by copolymerizing
acrylate monomers with thiols. This work explores the formation of
LCE polymer networks via photopolymerization reactions of diacrylate
liquid crystalline monomers with dithiols. Detailed analysis of model
systems based on monoacrylate–dithiol reactions indicates that
the polymer network architecture of LCEs prepared by this reaction
contains extensive unreacted thiol content as dangling ends. Further,
kinetic analysis indicates that polymerization in a liquid crystalline
phase strongly hinders the mobility of reactive species during the
formation of the LCE polymer network, which is evident in the substantial
difference in viscosity between liquid crystalline monomers (0.0195
Pa s) and non-liquid crystalline monomers (0.0025 Pa s). In copolymerization
with the diacrylate liquid crystal monomers, the dithiol comonomer
significantly decreases the elastic modulus and T
g. The residual thiol in the LCE polymer network can be
postfunctionalized with reactive additives.
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