Yuung-Ching Sheen

The thermal degradation of phosphorus-containing copolyesters

Abstract Two series of phosphorus-containing copolyesters were synthesized by poly-condensation of phosphorus-containing monomers: poly(ethylene terephthalate)-co-poly(ethylene phenylphosphonate)s [PET-co-PEPPs] and poly(ethylene terephathalate)-co-poly(ethylene DDP)s [PET-co-PEDDPs]. Both series are considered as flame retardants in polyester fibers and polyester plastics. The phosphorus-containing polymers were characterized by NMR, IR, TGA and acid titration. Experimental results indicated that for the PET-co-PEPP higher phosphorus content results in lower thermal stability. However, an insignificant effect on thermal stability was observed in the case of PET-co-PEDDPs. Thus, the incorporation of the phosphorus linkage into the main chain results in less thermal stability than that having the phosphorus linkage as a pendant group, i.e. PET-co-PEDDPs are more stable than PET-co-PEPPs.

UV Curable Organic-Inorganic Hybrid Materials

The broadband dielectric relaxation of a BaTiO3-polymer composite film was studied. The complex dielectric constant data from 10 Hz to 10 Hz reveals the existence of relaxation process at frequency of 10 MHz in the polymer composite. On the basis of Cole-Cole analysis, the relaxation time of the system is of order of 10 s. The understanding of the broad dispersion in dielectric behavior of polymer composite materials is needed to support next generation electronic devices used in wireless communication and related applications.