Potassium diphenyl sulfonate (SSK), poly-(sulfonyl phenylene phosphonate) (PSPPP), and their mixtures are proved to be effective flame-retardants for polycarbonates (PCs) by measuring the limited oxygen index values and UL-94 of blends. The flame-retardant systems are characterized by thermogravimetric analysis under dynamic conditions. The resulting data, together with the analysis of the activation energies, demonstrates that the additives ac-celerate thermodegradation, especially in the early stage, and different additives cause a different process in the final stage.

A new biodegradable starch graft copolymer, starch-g-poly(1,4-dioxan-2- one), was synthesized through the ring-opening graft polymerization of 1,4-dioxan-2-one onto a starch backbone. The grafting reactions were conducted with various 1,4-dioxan-2-one/starch feed ratios to obtain starch-g-poly (1,4-dioxan-2-one) copolymers with various poly(1,4-dioxan-2-one) graft structures. The microstructure of starch-gpoly (1,4-dioxan-2-one) was characterized in detail with one- and two-dimensional NMR spectroscopy. The effect of the feed composition on the resulting microstructure of starch-g-poly(1,4-dioxan-2-one) was investigated.

The solubility behaviors of poly(sulfonyldiphenylene phenylphosphonate) (PSPPP), a very efficient flame retardant for poly(ethylene terephthalate) (PET), in more than 50 solvents were examined. Its solubility parameters (δ) were determined by the intrinsic viscosity and turbidic titration methods. The two methods obtained consistent results, δ=21.0-21.6J1/2/cm and δ=21.0J1/2/cm3/2, and the three-dimensional solubility parameters were δ=18.9J1/2/cm3/2, δ=8.8J1/2/cm3/2, and δh=5.9J1/2/cm3/2. The miscibility of PSPPP with PET was estimated by the calculation of the heats of mixing, which were related to the difference between the solubility parameters of PSPPP and PET. Fourier transform infrared was used to examine the interactions between PSPPP and PET macromolecules, which were the internal factors of polymer-polymer miscibility. The results showed that PSPPP and PET were miscible within a very wide composition range, especially with less than 15wt% PSPPP, a composition of interest for the preparation of flame-retardant PET.

Poly (p-dioxanone)(PPDO)/montmorillonite nanocomposites were prepared through the in situ ring-opening polymerization of p-dioxanone (PDO) and three types of montmorillonites (natural sodium montmorillonite, montmorillonite modified by octadecyltrimethyl ammonium chloride, and montmorillonite modified by hydroxyethylhexadecyldimethyl ammonium bromine) in the presence of triethylaluminum. Montmorillonite could accelerate the polymerization of PDO, and the viscosity-average molecular weight of PPDO could reach 44,900g/mol in 0.5h. A nucleating effect of montmorillonite was observed, and the crystallization temperature of PPDO was increased by 18 8C. All three montmorillonites could improve the thermal stability of PPDO and increase the glass-transition and melting temperatures of PPDO.