A new intumescent flame retardant (IFR) system consisting of ammonium polyphosphate (APP) and charing-foaming agent (CFA) and a little organic montmorillonite (OMMT) was used in low-density polyethylene (LLDPE)/ethylene-vinyl acetate (EVA) composite. According to limiting oxygen index (LOI) value and UL-94 rating obtained from this work, the reasonable mass ratio of APP to CFA was 3 : 1, and OMMT could obviously enhance the flame retardancy of the composites. Cone calorimeter (CONE) and thermogravimetric analysis (TGA) were applied to evaluate the burning behavior and thermal stability of IFR-LLDPE/EVA (LLDPE/EVA) composites. The results of cone calorimeter showed that heat release rate peak (HRR-peak) and smoke production rate peak (SPR-peak) and time to ignition (TTI) of IFR-LLDPE/EVA composites decreased clearly compared with the pure blend. TGA data showed that IFR could enhance the thermal stability of the composites at high temperature and effectively increase the char residue. The morphological structures of the composites observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) demonstrated that OMMT could well disperse in the composites without exfoliation, and obviously improve the compatibility of components of IFR in LLDPE/EVA blend. The morphological structures of char layer obtained from Cone indicated that OMMT make the char layer structure be more homogenous and more stable.

A novel star-shaped cyclotriphosphazene substituted by glycinomethylesterphenoxy and its intermediates are synthesized from hexachlorocyclotriphosphazene (HCCP). The structures are characterized by 1 H NMR, 13 C NMR, 31 P NMR, FTIR and elemental analysis. Their thermal properties are clarified by thermogravimetric analysis (TGA), differential scanning calorimentry (DSC) and FTIR, while hydrolytic degradation behaviour is studied with UV-vis spectrophotometer and by measuring the weight loss, and the phosphorus content of residue. According to hydrolysis behaviour of hexa[p-(carbonylglycinomethylester)phenoxy]cyclotriphosphazene (HGPCP) under different conditions, it is easy to hydrolyze in hydrochloric acid (pH 1.0) than in phosphate buffer (pH 7.4) at 37℃. And the sample hydrolytic degradation still remains at the stage of side groups' break. The TGA data show that the thermal stability of the hexa[p-(aldehyde)phenoxy]cyclotriphosphazene (HAPCP), hexa[p-(carboxyl) phenoxy]cyclotriphosphazene (HCPCP) andHGPCP is so high that their char residues are 75%, 47% and 47% at 800℃, respectively, probably due to cross-linking between molecules.phosphazene, glycino methyl ester, synthesis, hydrolytic degradation, thermal properties

No abstract