We report on miscible blends comprised of linear-poly(ε-caprolactone) (l-PCL) and chemically crosslinked network-
PCL (n-PCL). The blends demonstrate unique Shape Memory Assisted Self-Healing (SMASH) property, which is the
materials ability to close local microscopic cracks and heal those cracks by bonding the crack surfaces. For Shape
Memory (SM) characterization, temporary deformation of the networks was achieved at room temperature. Samples
were temporarily fixed below their crystalline temperature (Tc) and shape recovery was triggered by a temperature above
the blends melting temperature (Tm). Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC)
were used to study the thermal properties of the blends and Dynamic Mechanical Analysis (DMA) and small-scale
tensile testing were used to obtain the mechanical properties and self-healing efficiencies of the blends.
We report on the effect of placement of nucleobase units, thymine or N6-(4-methoxybenzoyl)-adenine onto the ends of the mesogenic and fluorescent core: bis-4-alkoxy-substituted bis(phenylethynyl)-benzene (AA and BB type monomers). While the addition of these bulky polar groups significantly reduces the range of liquid crystalline behavior, mixing two complementary nucleobase-containing monomer units together yields stable thermotropic liquid crystalline phases.
Here, we focus on the effect of non-stoichiometric mixing of AA + BB monomers. Hydrogen bonding is shown to play an important role in the formation of these LC phases consistent with the formation of oligomeric or polymeric hydrogen bonding aggregates. Differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) have been used in our studies, revealed greater stability of LC phase formation for the 1:1 mixture.