Q2000

Example 4

Differential scanning calorimetry (“DSC”) was performed using a TA Instruments Q2000 (Texas Instruments, Inc., Dallas, Tex.) with an aluminum hermetic crucible. All tests were performed under nitrogen. All heating and cooling rates were set to 10° C./min. Samples that were tested before polymerization were heated from room temperature to 120° C., cooled to −50° C., and then heated to 200° C. Samples tested after crosslinking were heated from room temperature to 175° C., cooled to −50° C., and then heated to 200° C. Data shown are of the second heating cycle. Both the polymer and oligomer were analyzed using DSC.

The oligomer exhibits a glass transition at −12° C. and was not observed to crystallize over several months of storage at 4° C. A nematic-isotropic transition temperature was observed starting at 100° C. and was confirmed by POM. An unaligned sample, with a characteristic polydomain texture was cross-linked and then tested utilizing DSC. The resulting polymer network was viscoelastic at room temperature, with a glass transition of 19° C. (FIG. 30). A slight endothermic shift is observed at 155° C. This shift is characteristic of supercritical behavior of liquid crystal elastomers incapable of exhibiting complete clearing. This result is supported by POM observation of remnant order at 200° C.

Example 4

Differential scanning calorimetry (“DSC”) was performed using a TA Instruments Q2000 (Texas Instruments, Inc., Dallas, Tex.) with an aluminum hermetic crucible. All tests were performed under nitrogen. All heating and cooling rates were set to 10° C./min. Samples that were tested before polymerization were heated from room temperature to 120° C., cooled to −50° C., and then heated to 200° C. Samples tested after crosslinking were heated from room temperature to 175° C., cooled to −50° C., and then heated to 200° C. Data shown are of the second heating cycle. Both the polymer and oligomer were analyzed using DSC.

The oligomer exhibits a glass transition at −12° C. and was not observed to crystallize over several months of storage at 4° C. A nematic-isotropic transition temperature was observed starting at 100° C. and was confirmed by POM. An unaligned sample, with a characteristic polydomain texture was cross-linked and then tested utilizing DSC. The resulting polymer network was viscoelastic at room temperature, with a glass transition of 19° C. (FIG. 30). A slight endothermic shift is observed at 155° C. This shift is characteristic of supercritical behavior of liquid crystal elastomers incapable of exhibiting complete clearing. This result is supported by POM observation of remnant order at 200° C.

Example 8

Styrene (4.77 g) and Vinyl Phenoxy Benzocyclobutene (1.13 g) were dissolved in THF (3.98 g) along with V601™ initiator (70 mg) in an EZ Max™ 100 ml jacketed reactor (Mettler Toledo, Columbia, Md.) equipped with overhead stirring and nitrogen atmosphere. The solution was purged with nitrogen gas for 30 minutes, then heated to an internal temperature of 60° C. overnight. The resulting viscous solution was diluted with THF (20 ml) then precipitated into methanol (250 ml), filtered and dried overnight in vacuo to give the copolymer (4.23 g, 72% yield). Mn 36.6 k, Mw 79.1 k. The polymer curing kinetics were evaluated via differential scanning calorimetry (DSC, TA Instruments Q2000, TA instruments, New Castle, Del.) at a ramp rate of 2, 5, 10 and 20° C./min. The Kissinger method was used to determine a ring opening activation barrier of 24.2 kcal/mol. Thermal stability was evaluated using thermogravimetric analysis (TA Instruments Q5000) under a nitrogen atmosphere, wherein a solid polymer sample was placed in a TGA pan and run out to 400° C. at a rate of 10° C./min.

The TGA of the resulting copolymer exhibited a five percent weight loss value at 300° C.

Example 10

Differential scanning calorimetry (DSC) study was conducted using a TA Instruments, Q2000 at a heating rate 10° C./min. The instrument was calibrated for temperature and energy using the melting point and enthalpy of fusion of an indium standard. Thermal events (desolvation, melting, etc.) were evaluated using Universal Analysis 2000 software, version 4.1D, Build 4.1.0.16. Samples were weighed into A1 pans and scans ran from ˜25° C. to ˜270° C. at a rate of 10° C./min.