Synthesis, characterization and curing behavior of propyl-tri(phenylethynyl)silane

摘要

Propyl-tri(phenylethynyl)silane (( ph-C C) 3Si-CH2CH2CH3) monomer ( PTPES) was synthesized via Grignard reaction of propyl-trichlorosilane and phenylacetylene in the presence of magnesium and ethylbromide. Its chemical structure was characterized by nuclear magnetic resonance spectroscopy (H-1-NMR, C-13-NMR, and Si-29-NMR). The curing behavior and rheological characteristics of the PTPES were analyzed by differential scanning calorimetry ( DSC), Fourier transform infrared spectroscopy ( FTIR) and rheology techniques. The corresponding kinetic parameters and curing mechanism were also discussed by four well-known kinetic methods, i.e., Kissinger, Ozawa, Flynn-Wall-Ozawa and Friedman methods. Results showed that PTPES possessed a low melting point of 75 degrees C, a high gelatinization temperature of 333 degrees C and wide processing window of 258 degrees C. The cure schedule of PTPES could be determined as follows: ( 312 degrees C, 1 h) + ( 339 degrees C, 2 h) + ( 355 degrees C, 1 h) by dynamic DSC which was further verified by FTIR and rheology. The activation energy E-a was calculated as 122.83, 126.88 and 122.17 kJ/mol by Kissinger, Ozawa and Flynn-Wall-Ozawa methods, respectively. The pre-exponential factor lnA and the reaction orders n and m were 23.15 (s(-1)), 1.43 and 0.36, respectively. The autocatalytic kinetic model was found to be the best description of the curing process by the Friedman method.