Proposed Applications of PCHE-based Materials

Although PCHE based materials are not commercially available as of this writing, a variety of potential applications have been outlined in scientific publications and in the patent literature. Clearly, the increase in Tg upon hydrogenation (and the commensurate improvement in heat distortion characteristics) 

Various aspects of the use of PCHE and related materials as a dielectric layer in capacitor films has been described and patented by several workers [72,73]. The material properties that are important for this application are low moisture absorption (which allows for the formation of thin films with minimal pinhole formation), a high heat distortion temperature, and high breakdown voltage. 

The preparation of foams of PCHE and copolymers has also been claimed [79]. A combination of a low-boiling hydrocarbon (butane) foaming agent and a higher boiling hydrocarbon plasticizer (toluene) were used to prepare foams. The increased heat distortion temperature of PCHE has been proposed to lead to utility in insulating foams for hot water pipes and similar applications. In addition, the superior weatherability of this material would allow use in applications in which the product was subjected to UV exposure. 

The use of hydroxyl-substituted PCHE as a positive photoresist substrate has been patented [80,81]. Hydrogenation improves transparency into the deep UV region (200-300 nm) compared with materials containing aromatic rings and allows for smaller dimensions to be patterned. Features with good definition have been reported using partially hydrogenated substrates. 

PCHE-containing block copolymers have been reported to have utility as melt spun elastomeric fibers [82]. The improved melt processability of these materials (compared with partially saturated block copolymers) allows them to be processed into small denier fibers with excellent tenacity and ultimate elongation. 

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