Metallocene
Mostrando 13-16 de 16 artigos, teses e dissertações.
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13. Caracterização vibracional e térmica de blendas de LDPE e m-LLDPE / Thermal and vibrational characterization of blends: Blends of low density polyethylene (LDPE) and linear low density polyethylene synthesized with the metallocene catalyst (m-LLDPE)
Blends of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) are used commercially to improve the final properties of the products and their process, reduce the production cost having as their main segment packing film. The LLDPE used in this work was synthesized with the metallocene catalyst (m-LLDPE), which was projected to offer b
Publicado em: 2005
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14. The role of defect microstructure in the crystallization behavior of metallocene and MgCl2-supported Ziegler-Natta isotactic poly(propylenes)
The intermolecular defect distribution of poly(propylenes) of the Ziegler-Natta (ZN) and metallocene (M) types is assessed by classical fractionation and analysis of the fractions by GPC and 13C NMR. In addition, the linear growth rates, a property sensitive to differences in defects distribution in the poly(propylene) chain, are used to infer the stereobloc
Polímeros. Publicado em: 2003-12
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15. Técnica do Pulso Eletroacústico para medidas de Perfis de Carga Espacial em Dielétricos / Electro-acoustic Pulse to Measure Space Charge Profile in Dielectric Materials
It is described the implementation of the electroacustic pulse technique, PEA, for the determination of space charge profiles in dielectrics. The method is based on the acoustic signal generated by the application of a voltage pulse with short duration on the sample. The acoustic signal generated by pulse is detected by using a piezoelectric transducer coupl
Publicado em: 1999
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16. Polimerização de etileno com zirconoceno-mao suportado em peneiras moleculares
In this work, it was studied the polymerisation of ethylene catalysed by bis- ciclopentadienilzirconium(IV) dichloride supported in three molecular sieves (Zeolite Y, AlPO-VPI-5 and MCM-41). The zirconocene (Cp2ZrCI2) it was prepared by the reaction of the cyclopentadienylsodium with zirconium(IV) chloride, in tetrahydrofuran. The molecular sieves were synth
Publicado em: 1999