Properties and structure of high temperature resistant cyanate ester/polyethersulfone blends using solvent-free tougheni
- PDF / 1,341,609 Bytes
- 13 Pages / 439.37 x 666.142 pts Page_size
- 86 Downloads / 184 Views
Properties and structure of high temperature resistant cyanate ester/polyethersulfone blends using solvent‑free toughening approach Lyaysan Amirova1 · Fabian Schadt1 · Markus Grob1 · Christian Brauner1 · Thomas Ricard2 · Tobias Wille3 Received: 31 August 2020 / Revised: 5 November 2020 / Accepted: 13 November 2020 © The Author(s) 2020
Abstract A high temperature resistant novolac cyanate ester was blended with polyethersulfone (PES) with different molecular weights using the solvent-free approach. The phase separation, curing behavior and thermal properties were studied using hot stage microscopy, differential scanning calorimetry and dynamic mechanical analysis. Results showed the difference in the morphology for blends with different molecular weight PES explained by possible network formation. The influence of PES content on the glass transition temperature and mechanical properties was investigated. The most significant toughening effect (increase of 132% in fracture toughness) was achieved on a functionalized low molecular weight PES (20 parts per hundred of resin, phr). Rheology investigation allowed to estimate the optimal content of PES (15 phr) for further prepreg manufacturing. Keywords Cyanate ester · Toughening · Polyethersulfone · Phase separation · Glass transition temperature · Fracture toughening
Introduction Cyanate ester resins are currently used for many important applications such as high-temperature adhesives, and advanced composite matrices in the aerospace and automotive industry [1–3]. A unique combination of properties such as high temperature stability and chemical resistance, low moisture uptake and low dielectric * Lyaysan Amirova [email protected] 1
Institute of Polymer Engineering, University of Applied Sciences Northwestern Switzerland, Klosterzelgstrasse 2, 5210 Windisch, Switzerland
2
North Thin Ply Technology, Chemin du Closel 3, 1020 Renens, Switzerland
3
German Aerospace Center, Lilienthalpl. 7, 38108 Braunschweig, Germany
13
Vol.:(0123456789)
Polymer Bulletin
constant in the cured state, as well as low viscosity in the uncured state (lowest viscosity of all high temperature resins) has led to their use in low-volume highperformance applications. However, their widespread use is unfortunately limited in many applications by their inherent brittle behavior due to their high crosslink density [4, 5]. The incorporation of thermoplastics into such networks has emerged as a promising approach to improve toughness, especially when high values of elastic moduli and glass transition temperature are required. The most common thermoplastic tougheners for epoxy systems are polysulfones (PSF), polyetherimides (PEI) or polyethersulfones (PES) [6–9]. The process of phase separation during the cure of thermoset/thermoplastic blends is essential to generate the toughened thermosets. The degree of toughening is related to the degree of phase separation and the generated morphologies. The latter depends on curing conditions, molecular weight and content of the thermoplast
Data Loading...
