Thermoset films derived from

Fabrication and Properties of Thermoset Films Derived from Bis-Benzocyclobutene for Multilayer Applications... 

Figure 10 shows the dispersion surface of the thermoset film derived from the BCB-2 monomer. The dielectric constant was found to be relatively flat over this surface with a value of er -2.66 + 0.1. The error in this measurement was slightly less than indicated for the previous figure because the sample dimensions were more well defined. As in the previous figure, the dielectric constant increases near 10 MHz because of losses in the test leads. 

Figure 11. Frequency dependence of the dissipation factor of thermoset films derived from BCB-1 and BCB-2 monomers.

The dielectric properties of two different thermoset films derived from bis-benzocyclobutene monomers were described. The dielectric constant was 2.65 + 0.1. The dissipation factor was below 0.001 above 1.0 kHz. These values are significantly lower than those reported for polyimide thin films. Therefore, the BCB films described in this work are attractive candidates for interlevel dielectrics in dense multilevel interconnection structures. 

At one time the definition of lacquer (as distinguished from other finishes) was limited so that the film-forming ingredient in a lacquer formulation was specified as cellulose nitrate or other cellulosics, but the definition has now been broadened to include other film formers as well. Typical lacquers include those based on nitrocellulose, other cellulose derivatives, vinyl resins, acrylic resins, and so forth. Although meant to describe only thermoplastic film formers, the term lacquer has been extended to thermosetting coatings as well. 

Few examples of nanocomposites in which the cellulosic nanostructure is used in biobased thermosets can be also foimd. Due to the fact that these environment friendly composites suffer from several limitations, such as low mechanical properties due to low strength in reinforcement plus inadequate interfacial strength, and that cellulose nanostructures have been shown to have significant potential as a reinforcement, the possibility of using cellulose nanofibers as reinforcements in a bio-derived resin was revised. In Masoodi et al. [200], cellulose nanofibers were used as reinforcements in the forms of layered films, while in Lee et al. [201] the stability of the gas-soybean oil foam templates and the mechanical properties of the polymer nanocomposite foams are enhanced upon the addition of bacterial cellulose nanofibrils. Other examples of biobased thermosets containing cellulosic nanoreinforcements are the work of Shibata [202] in which the use of a biobased epoxy was revised, and systems in which cellulose nanocrystals are incorporated in biobased polyurethanes [203,204], Few examples exist also in the literature on the polymerization of furfuryl alcohol in presence of CNR [205,206] in these papers, the authors established the feasibility of producing furfuryl... 

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