Curing kinetics and mechanism of novel high performance hyperbranched polysiloxane/bismaleimide/cyanate ester resins for resin transfer molding

Abstract

Curing kinetics and mechanism determine the structure and property of thermosetting resins and related composites. The curing kinetics and mechanism of a novel high performance resin system based on hyperbranched polysiloxane (HBPSi), 2,2 0 -diallylbisphenol A modified bismaleimide (BD), and cyanate ester (CE) resins for Resin Transfer Molding (RTM) technique were systemically studied by Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR) spectra, and torque rheometer. Results show that the addition of HBPSi to BD/CE resin not only decreases the initial curing temperature and apparent activation energy, but also changes the curing mechanism, and thus the structure and properties of resultant crosslinked networks. An ''Interpenetrating network (IPN)-coupling structure'' is proposed to be formed in the HBPSi/BD/CE system, which is different from traditional ''IPN'' structure in BD/CE resin. The simulation of curing reaction suggests that the variety of the curing activity leads to the difference between the curing behaviors of BD/CE and HBPSi/BD/CE resins, which is in good agreement with FTIR and DSC analyses.

Ameliorated Mechanical and Dielectric Properties of Heat-Resistant Radome Cyanate Composites

“…At the temperatures of 200~270 °C when approaching the glass-transition temperature ( T g ), the transformation of molecular-chain motions from localized vibrations to random global displacements results in the nosedive ability to store elastic deformation energy [ 26 , 27 ]. After the temperature reached T g ~ 270 °C, the polymer molecules of all the three composites will exist in a loose or free aggregation state when elastic energy storage promptly tends to almost zero [ 28 ].…”

Hyperbranched polysiloxane‐based diglycidyl ether of bisphenol a epoxy composite for low k dielectric application

“…HPSiE synthesized (Scheme ) by the hydrolyzation as per the reported procedure, distilled water and GPTMS at a molar ratio of 1.6:1 were mixed uniformly, concentrated HCl was added to the solution to adjust the pH of 5.5–6.5 and stirred for 10–15 min after the temperature was raised to 50°C, the reaction was continued for 5 h, and dried in vacuum to give the epoxy group as terminal groups of the HPSiE .…”

Effect and origin of the structure of hyperbranched polysiloxane on the surface and integrated performances of grafted Kevlar fibers

“…On the other hand, to avoid a high content of C-C bonds in the resultant HPSi, MPS that has C=C bond was also employed to take part in the hydrolysis and polymerization to get better UV resistance. Therefore, two silanes, GPTMS and MPS, were utilized to synthesize hyperbranched polysiloxane, which is different from almost all available HPSis because which were synthesized through single silane [37][38][39]. The synthesis process is shown in Scheme 1.…”