Polycarbonate (PC)/ultrafine polyhedral oligomeric octaphenyl silsesquioxane (OPS) composites were prepared by melt mixing method. The morphology and rheological behavior of PC/ultrafine OPS composites were investigated by scanning electron microscopy (SEM) melt indexer, high pressure capillary rheometer, and strain-controlled rheometer. The SEM results show that ultrafine OPS is dispersed in PC as the size of submicron and has a good dispersion in PC matrix, and a certain extent compatibility between PC and ultrafine OPS is found. OPS aggregation is found through the cross section at high ultrafine OPS content. The results of melt flow index (MFI) and capillary rheometer indicate that ultrafine OPS can effectively decrease the apparent viscosity and improve the flow property and processability of PC matrix as a lubricant. The oscillatory rheological analysis indicates that the storage modulus increases with increasing OPS content, and the appeared platform of storage modulus exhibits the solid-like behavior and the formation of three-dimensional network in the composites. The complex viscosity of PC/OPS composite shows a quasi-Newtonian regime at low OPS content and a typical shear-thinning behavior at high OPS content. The Cole–Cole, Han, and van Gurp plots show that ultrafine OPS particle is compatible with PC at low content (≤3 wt %), and interaction between particle and particle is the major factor when OPS at high content (≥6 wt %). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43638.

The thermal degradation of acrylonitrile-butadiene-styrene (ABS) added ammonia polyphosphate (APP) or APP/montmorillonite (MMT) nanocomposite was studied. The whole degradation progress of ABS could be regarded as the combination of the thermal degradation of polystyrene (PS) and polybutadiene (PB). The PB influences the formation of char while PS influences the maximum mass loss rate and its decomposition temperature. APP or APP/MMT nanocomposite could decrease the maximum mass loss rate and promotes the formation of char. A SiO₂ network was formed on the char surface of the ABS-APP/MMT composite which could improve the strength of the char and flame retardancy of ABS. It was found that when APP/MMT mixture or APP/MMT nanocomposite are added to ABS, NH₃ (the gas product of APP) was buried in the residue and released until full degradation of ABS. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40704.

Polyhedral oligomeric octaphenyl silsesquioxane (OPS) and polyhedral oligomeric silsesquioxane containing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-POSS) with polycarbonate (PC) were each prepared by twin screw extrusion. Their flammability was studied by cone calorimetry under different heat fluxes (35 and 50 kW/m²). In the cone calorimeter testing, thermocouples were used to measure the temperature at the top and bottom of the composites. Compared to the DOPO-POSS/PC composite, the char layer of the OPS/PC composite is better for preventing heat transfer, the temperature change indicates that OPS/PC composite has a longer period of char formation, and the organization of their char materials are different. The DOPO-POSS/PC composite has a harder char layer than the OPS/PC composite, but the OPS/PC composite char layer is more compact. The char layer macrostructure was studied with scanning electron microscopy (SEM) and EDS, which indicated that there are many bubbles and pores in the DOPO-POSS/PC composite. EDS showed that there was some Si content in the exterior and interior char for the DOPO-POSS/PC composite; there is a greater Si content in the exterior OPS/PC char residue than in the interior. The storage modulus of OPS/PC composite was higher than the PC control and DOPO-POSS/PC composite at low frequencies. The values of η* of the OPS/PC composite were higher than the PC control and DOPO-POSS/PC composite at low frequencies; also, the PC control exhibits a quasi-Newtonian regime, but the OPS/PC and DOPO-POSS/PC composites exhibit typical shear-thinning behavior. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39892.

Polyhedral oligomeric octa(propargylaminophenyl)silsesquioxane (OPAPS) was used to prepare composite resins with prepolyarylacetylene (prePAA). The curing and thermal behaviors of the PAA/OPAPS composites were studied through Fourier-transform infrared (FTIR), X-ray diffraction (XRD), differential scanning calorimetric (DSC), thermogravimetric (TGA), and scanning electron microscopic (SEM) analysis and by direct observation. The morphologies of the PAA/OPAPS resins proved that there was good compatibility between PAA and OPAPS. FTIR analysis indicated formation of a conjugated diene and aromatic ring groups in the thermal curing process of the resins. DSC analysis implied that the addition of OPAPS to prePAA could decrease the exothermic heat and widen the temperature range in the curing process of prePAA. According to TGA analysis, a 10 wt % addition of OPAPS to PAA can maintain the thermal stability of PAA in N₂ atmosphere and somewhat enhance the thermal-oxidative stability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Composites of ultrafine polyhedral oligomeric octaphenyl silsesquioxane (OPS) and polycarbonate (PC) were prepared by melt blending. The mechanical and thermal properties of the composites were characterized by tensile and flexural tests, impact test, differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA), and thermal gravimetric analysis (TGA). Rheological properties of these melts were tested by torque rheometer. The flame retardancy of the composites was tested by limiting oxygen index (LOI), the vertical burning (UL-94), and cone calorimeter test. The char residue was characterized by scanning electron microscope (SEM) and ATR-FTIR spectrum. Furthermore, the dispersion of OPS particles in the PC matrix was evidenced by SEM. The results indicate that the glass transition temperatures (T_g) and torque of the composites decrease with increasing OPS loading. The onset decomposition temperatures of composites are lower than that of PC. The LOI value and UL-94 rating of the PC/OPS composites increase with increasing loading of OPS. When OPS loading reaches 6 wt %, the LOI value is 33.8%, UL-94 (1.6 mm) V-0 rating is obtained, and peak heat release rate (PHRR) decreases from 570 to 292 kJ m⁻². © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012