The thermal properties of isotactic polypropylene (iPP) reinforced with polyaniline‐grafted‐short glass fibers (PAn‐g‐SGF) at 10, 20, and 30 wt% concentration and iPP blended with 5 wt% PP‐grafted‐maleic anhydride (PP‐gMA) and 30 wt% of PAn‐g‐SGF were investigated. iPP crystallizes into a spherulitic morphology, the microfiller promoted larger spherulite size and higher dynamic modulus, but the overall degree of crystallinity decreased as the concentration of PAn‐g‐SGF increased. The melting temperature, Tm, was not influenced by the microfiller. However, the crystallization temperature, Tc, as determined by DMA, first decreased reaching a minimum at ca. 20 wt%, and then increased, in contrast with Tc determined by DSC, it increased as concentration increased. The initial reduction in Tc observed by DMA seems to be associated with the crystallites growing from the microfiller into the matrix, the overall molecular dynamics then being less affected. On the other hand, increase in Tc above 20 wt% concentration suggests that the percolation threshold could be responsible for these results. Addition of the maleic anhydride copolymer produced higher shear modulus, transition temperatures, and activation energy, suggesting higher interaction between microfiller and polymer matrix. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers

Isothermal crystallization kinetics of composites of isotactic-polypropylene (iPP) reinforced with polyaniline-grafted short glass fibers (PAn-g-SGF) were studied by differential scanning calorimetry (DSC). The concentration of PAn-g-SGF ranged from 10 to 30 wt%. Furthermore, a composite of iPP blended with 5% polypropylene-grafted maleic anhydride and 30 wt% PAn-g-SGF was also studied. DSC showed that the crystallization temperature of iPP, Tc, was significantly increased by the microfiller. Isothermal crystallization results showed that the kinetics of neat iPP is well described by the Avrami model, with half-time crystallization τ1/2 in the range of 3 to 22 mins. Regarding the composites, τ1/2 was five times faster than neat iPP. Furthermore, the kinetics of crystallization was described by the Avrami model only at temperatures not too close to the respective crystallization temperature Tc. That is, the PAn-g-SGF microfiller acted as nucleating agent was significantly accelerating the rate of crystallization of the composites. The rate of crystallization was even faster than when using only bare glass fibers. Hot-stage polarized optical microscopy showed transcrystallinity induced by PAn-g-SGF; that is, crystallization in the composites starts first on the surface of the microfillers and then spreads out into the polymer matrix. This might explain the extremely fast rate of crystallization kinetics observed in the composites.

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Key indicators: single-crystal X-ray study; T = 298 K; mean (C-C) = 0.006 Å; R factor = 0.039; wR factor = 0.097; data-to-parameter ratio = 15.6.In the title compound, [Ru(CH 3 (3) ]. The packing of the complexes is assured by C-HÁ Á ÁO and C-HÁ Á Á interactions. Related literatureFor complexes with metal-S and metal-P bonds, see: Lu et al.

Objective: To evaluate the CaO made from oyster shell (C. virginica) as a heterogeneous catalyst in the transesterification of edible vegetable oil used for the production of biodiesel. Design / methodology / approach: A completely randomized experimental design was used, which grouped 3 treatments with 3 repetitions, generating a total of 9 experimental units. The response variable was the performance of the transesterification reaction that was evaluated with 2%, 3% and 4% of CaO obtained from oyster shells. The density, kinematic viscosity, acidity, and conversion efficiency to methyl esters were determined by 1H NMR of the products of each treatment. Results: The treatment with 3% catalyst showed the highest reaction yield (92.2%) compared to the treatments with 2% (86.8%) and 4% catalyst (87.13%). The 1H NMR spectra confirmed the presence of methyl esters in the product of the three treatments. The treatment with 3% and 4% by weight of catalyst presented products with similar characteristics with acceptable values ​​of density, viscosity and acid number in accordance with the ASTM D6751 and EN1421 standards. Study limitations / implications: A concentration of 2% by weight of CaO generates a conversion percentage far from the content of methyl esters established by the ASTM D6751 and EN14214 Standards (> 96.5%). Findings / conclusions: 1H NMR results indicate that the conversion efficiency to methyl esters is positively affected by the amount of catalyst. In the treatments with catalyst loading greater than 2%, the conversion to methyl esters increased significantly to values ​​around 90%.