The organic–inorganic hybrid nanocomposites from high-impact polystyrene/octavinyl polyhedral oligomeric silsesquioxane (HIPS/POSS) containing various percentages of POSS were prepared by free radical polymerization and characterized by Fourier transform infrared spectroscopy (FTIR), 1H-NMR, thermal gravity analysis (TGA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The octavinyl POSS has formed covalent bond connected PS-POSS hybrid with polystyrene. POSS can well disperse in the composites at the composition of 0.5 and 1 wt%. The mechanical properties and thermostability of HIPS/POSS nanocomposites were significantly improved. The tensile strength, the izod impact strength, and the elongation at break of the nanocomposite containing 1 wt% of POSS was increased, respectively, by 15.73%, 75.62%, and 72.71% in comparison with pristine HIPS. The thermal decomposition temperature of HIPS/POSS (1 wt% of POSS) was 33°C higher than that of pristine HIPS. The HIPS/POSS nanocomposites showed great potential for applications in many fields, such as electric appliance and automotive trim. POLYM. COMPOS. 37:1049–1055, 2016. © 2014 Society of Plastics Engineers
Fluorinated polyurethane–acrylate (FPUA) hybrid emulsion was prepared by copolymerization of polyurethane, methyl methacrylate, and 1H,1H,2H,2H-heptadecafluorooctyl acrylate (FA) via emulsion polymerization in the presence of a perfluoronated reactive surfactant. The polyurethane was synthesized from isophorone diisocyanate, poly(propylene glycol)-1000, dimethylolpropionic acid, 1,4-butanediol, and 2-hydroxyethyl methylacrylate. The influence of the monomer on the surface properties, wetting behaviors, particle size, and viscosity of the emulsion was investigated. The mechanical properties of FPUA latex films were improved, and water absorption and contact angle were improved with the addition of methyl methacrylate and FA. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43357.
Poly (p-phenylene benzobisoxazole)/carbon nanotube (PBO/CNTs) composites have already been experimentally synthesized with the outstanding mechanical and electrical properties. Carboxylic carbon nanotubes (CNT-COOH), obtained by acid treatment, can better disperse than pristine nanotubes in PBO matrix, which is estimated due to hydrogen bonds between them and investigated by Quantum Mechanics/Molecular mechanics (QM/MM) calculation. In the dynamic simulation, the N atoms in PBO and H atoms in carboxyl can be close enough to form hydrogen bond and the angle of oxygen–hydrogen–nitrogen (OHN) is obtuse, suitable for hydrogen bond. Further more, the electrostatic potential (ESP) and ESP fit charge of N and O atoms in PBO has been measured by Density Functional Theory (DFT) calculation to prove that hydrogen bonds can be formed only by N atoms in the heterocycle of PBO and H atoms in carboxyl of the CNT-COOH. POLYM. COMPOS., 36:1454–1461, 2015. © 2014 Society of Plastics Engineers
A series of magnetic fluorinated polybenzobisoxazole (6FPBO)/silica-coated Fe3O4 magnetic nanoparticles composites were synthesized through in-situ polymerization. The structure and morphology of the obtained nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, and scanning electronic microscope (SEM). The SEM images indicated that the crosslinking structure is formed in magnetic 6FPBO nanocomposites. The magnetic and electromagnetic properties of magnetic 6FPBO nanocomposites in the 2–18 GHz frequency range were characterized by vibration sample magnetometer and vector network analyzer, respectively. The calculated reflection loss of the as-prepared magnetic 6FPBO nanocomposites showed that the best microwave absorption reached to −20 dB at 17 GHz with a matching thickness of 3.00 mm. POLYM. COMPOS., 36:884–891, 2015. © 2014 Society of Plastics Engineers
Summary: Host–guest systems have been prepared using the blends and copolymers consisting of the host molecule poly(p-phenylene benzobisoxazole) (PBO) with a higher bandgap of 2.93 eV and the guest molecule poly(2,5-thienylbenzobisoxazole) (PBOT) with a lower bandgap of 2.57 eV. These systems have been investigated using photoluminescence (PL) spectra and time-resolved PL decay dynamics. Both PBOT-PBO copolymers and PBOT/PBO blends with the PBOT compositions less than 20% demonstrate higher intensities and narrower bandwidths in solid-state emission compared to that of PBOT, as well as larger fractions of the shorter lifetime component in PL decay dynamics. A general scheme on intrachain and interchain exciton migration and trapping mechanism has been proposed to interpret the phenomena in both solutions and thin films. Particularly, a competition in trapping exciton between PBO aggregates and isolated PBOT chromophores has been revealed.