Synthesis, characterization, and non-isothermal curing kinetics of two silicon-containing arylacetylenic monomers

Abstract

Vinyltri(phenylethynyl)silane ((ph-C:C) 3 -Si-C=CH 2 ; VTPES) and phenyltri(phenylethynyl)silane ((ph-C:C) 3 -Si-ph; PTPES) were synthesized by Grignard reaction. Their molecular structures were characterized by means of 1 H NMR, 13 C NMR, 29 Si NMR, and FT-IR spectroscopy. Their nonisothermal thermal curing processes were characterized by DSC, and the corresponding kinetic data, for example activation energy (E), pre-exponential factor (A), and the order of the reaction (n), were obtained by the Kissinger method. The results showed that the melting points of VTPES and PTPES were 84 and 116°C, respectively. Their curing reaction rates were consistent with first-order kinetic equations. VTPES monomer had a lower activation energy and curing temperature as a result of coordination between reactive groups.

Non-isothermal curing kinetics, chemorheological behaviour, and IR spectral study of two trifunctional phenylethynyl-terminated imide oligomers compared with the corresponding bifunctional structure

“…The most significant differences between the IR spectra of the various structures are shown in Figure 7. The structure of cured BPEPA resin (1b) shows a very weak band at 924 cm -l , which was assigned by other authors to the trans C-H out-of-plane deformation vibration [46,48]. However, for the cured trifunctional resins, m-TPEPA (2b) and p-TPEPA (3b), the band at 924 cm -l is very weak.…”

“…In the later part of the conversion, the lower E a values of the trifunctional oligomers, especially p-TPEPA, may lead to different curing reactions, compared with the sustained growth of the E a values of BPEPA. The theoretically predicted values for cyclotrimerisation based on bond energy calculations for the thermal polymerisation of the acetylenic group and the heats of polymerisation for the phenyl and vinyl-substituted acetylenic monomers were 189, 338 and 288 kJ mol -1 , respectively, suggesting that trimerisation of the acetylenic groups might be the preferred reaction pathway [46]. Because of the lower steric factor restrictions of the main chains and the benzene ring next to the ethynyl group, the structure in the bifunctional phenylethynyl-terminated model compounds was replaced by simple ethynylto-ethynyl addition reactions to form linear and crosslinked polyene structures.…”

Thermal curing of novel carborane-containing phenylethynyl terminated imide oligomers

“…The analysis of curing kinetic for imide systems was performed with Kissinger and Crane methods. [25][26][27][28][29][30] According to Kissinger equation (eqn (1)), the activation energy E can be obtained from the slope of the plots of ln(b/T p 2 )…”