Thermal properties of bio flour-filled polypropylene bio-composites with different pozzolan contents

In this study, the thermal properties of bio-flour-filled, polypropylene (PP) bio-composites with different pozzolan contents were investigated. With increasing pozzolan content, the thermal stability, 5% mass loss temperature and derivative thermogravimetric curve (DTG_max) temperatures of the bio-composites slightly increased. The coefficient of thermal expansion (CTE) and thermal expansion of the bio-composites decreased as the pozzolan content increased. The glass transition temperature (T _g), melting temperature (T _m) and percentage of crystallinity (X _c) of the bio-composites were not significantly changed. The thermal stability, thermal expansion and X _c of the maleic anhydride-grafted PP (MAPP)-treated bio-composites were much higher than those of non-treated bio-composites at 1% pozzolan content due to enhanced interfacial adhesion. X-ray diffraction (XRD) analysis confirmed the crystallinity of pozzolan-added bio-composites. From these results, we concluded that the addition of pozzolan in the bio-composites was an effective method for enhancing the thermal stability and thermal expansion.     

Theoretical study of the reaction of acrylonitrile on Si(001)

Two recent experiments for adsorbed acrylonitrile on the Si(001) surface reported different adsorption structures at 110 and 300 K. We investigate the reaction of acrylonitrile on Si(001) by first-principles density-functional calculations. We find that the so-called [4+2] structure in which acrylonitrile resides between two dimer rows is not only thermodynamically favored over other structural models but also easily formed via a precursor where the N atom of acrylonitrile is attached to the down atom of the Si dimer. The additional initial-state theory calculation for the C 1s core levels of adsorbed acrylonitrile provides an interpretation for the observed low- and room-temperature adsorption configurations in terms of the precursor and [4+2] structures, respectively.     

Ring-opening polymerization of 1-(p-substituted phenyl)-2-vinylcyclopropanes by Ziegler–Natta catalysts

1-(p-Substituted phenyl)-2-vinylcyclopropanes such as 1-phenyl-2-vinylcyclopropane (I_a), 1-(p-chlorophenyl)-2-vinylcyclopropane (I_b), 1-(p-anisyl)-2-vinylcyclopropane (I_c), and 1-(p-tolyl)-2-vinylcyclopropane (I_d) were prepared and polymerized radically, cationically and with Ziegler–Natta catalysts. I_a and I_b polymerized exclusively in 1,5-fashion with radical initiators. However, I_c and I_d polymerized in 1,5-fashion only with Ziegler–Natta catalysts. All polymers were soluble in ordinary organic solvent and solution-cast films were clear and flexible, showing T_g values in the range of 39–71°C. Spectral data indicated that the double bonds of the polymer chains were in trans form in all cases. The difference between the polymerizabilities of different monomers are interpreted in terms of electronic properties of substituents.     

Alkylation of 4,5-dichloropyridazin-6-one with α,ω-dibromoalkanes or 4,5-dichloro-1-(ω-bromoalkyl)pyridazin-6-ones

Alkylations of 4,5-dichloropyridazin-6-one (1) with dibromoalkanes 2 or 3 in the presence of potassium carbonate or tetrabutylammonium bromide/potassium hydroxide were investigated under restricted condition. Reactions of 1 with 2 or 3, except for 2b and 3b , in the presence of potassium carbonate or tetrabutylammonium bromide/potassium hydroxide gave only the N-alkylation products 3 and/or 4. Alkylation of 1 with 2b or 3b in the presence of potassium carbonate yielded the N-alkylation products 3b and/or 4b and the O-alkylation product 5 as the main product, whereas treatment of 1 with 2b or 3b in the presence of tetrabutylammonium bromide/potassium hydroxide afforded selectively the N-alkylation products 3b and/or 4b.