The synthesis of the LCER was carried out in two steps.
Two LCER networks synthesized in this experiment were cured using DDS and DDM as curing agents, respectively.
The spectra of BHPPDO and the LCER were taken by dispersing them in KBr followed by pelletization.
Liquid crystalline phase transition behavior of the LCER was examined using differential scanning calorimetry (DSC: DSC Q200, TA Instruments).
The structure of the synthesized LCER was confirmed by FTIR.
Figures 3 and 4 show the [sup.1]H NMR spectra of BHPPDO and the LCER, respectively.
The chemical structure of LCER was also confirmed by mass spectra.
Figure 6 shows the DSC diagram of the LCER obtained at a heating rate of 10[degrees]C [cm.sup.-1] and a cooling rate of 10[degrees]C [cm.sup.-1].
With regard to this, LCER have been found to be very promising in this field: they can be oriented more easily before the crosslinking is performed than both ordinary and liquid crystalline thermoplastic polymers.
Where optical and electro-optical applications are concerned, main chain LCER exhibit some advantages: first, because of their low monomeric viscosity, the curing resin can be easily oriented before gelation; then the reduced system mobility prevents the chain relaxation.
In other terms, the microstructure of LCER is predominant but consists of anisotropic domains with properties, such as strength.