Phthalonitrile-Terminated Silicon-Containing Oligomers: Synthesis, Polymerization, and Properties

Abstract

A novel silicon-containing phthalonitrile-terminated fluorene-based oligomer was synthesized by a novel method, and the structure was characterized by Fourier transfrom infrared spectroscopy, 1H NMR, and gel permeation chromatography. The prepolymer was obtained by blending the oligomer with curing agent, and the curing behavior was systematically studied by differential scanning calorimetry, infrared, and rheology tests. The oligomer exhibited excellent solubility, even in acetone under room temperature, which greatly facilitated prepreg preparation. The quartz fiber-reinforced composites were prepared by a hot-pressing process. The cured polymers and composites possessed excellent thermal properties. Under inert atmosphere, the maximum 1000 °C residual weight was 88% and the 5% thermal degradation temperature was 662 °C. More importantly, no obviously decrease in storage modulus was detected until 500 °C, suggesting sufficiently high heat resistance. Additionally, the composites exhibited outstanding flame retardant, ablative, and dielectric properties. Consequently, the current resin could be potentially applied in either high-temperature structural or functional composites.

Fluorinated Phthalonitrile Resin with Excellent Thermal Stability and Low Dielectric Constant for High‐Frequency Electronic Packaging

“…[ 3 ] Additionally, a relatively weak and sluggish exothermic peak appeared at 311 °C, which was interpreted by the fact that the cross‐linking reaction of cyano groups could occur slowly at high temperatures. [ 3,5,41 ] The PFDP oligomer has a lower softening point (101 °C) than traditional or other new PN monomers (120–230 °C), [ 42–45 ] but it is slightly higher than that of PBDP [ 40 ] with a similar structure. Possible explanation would be that the aromatic ether linkages on the monomer increase the flexibility of PFDP molecular chain, and the free volume of ‐CF 3 is larger than that of ‐CH 3 , resulting in lower molecular flexibility than that of PBDP.…”

“…[ 1–3 ] Phthalonitriles (PNs) are widely concerned in high‐frequency field due to its low intrinsic dielectric constant ( D k ) and dielectric loss ( D f ), low moisture absorption, and good heat resistance. [ 4,5 ]…”

Preparation and characterization of a high heat resistant phthalonitrile resin modified by polyborosilazane ceramic precursor

“…Another approach is that inorganic particles (BN, SiO 2 , Al 2 O 3 ) within a high melting point are introduced into the polymer-based matrix to improve the heat-resistance of the polymerbased material. 12,20,21 The thermal performance of the resin is improved by isolating or reducing the direct contact of hightemperature gases with the polymer-based matrix. The benefits of this approach are the simplicity of the preparation process, the low cost, (T d5% = 512.0 C).…”

“…However, the curing temperature of SiBPPN is not completed until 400°C. These inorganic elements are introduced into the molecular chain segments of the polymer via chemical reactions 16–19 . Under high temperatures, these heat‐resistance materials prevent further damage to the resin by forming a heat‐resistance oxide film (SiO 2 , Al 2 O 3 ).…”

A Phthalonitrile Resin with a Low Melting Point and High Storage Modulus Containing High‐Density Aromatic Ether Bonds

“…Among numerous kinds of polymer materials, phthalonitrile polymers are famous for its excellent chemical resistance, high glass transition temperature, excellent thermomechanical properties and water resistance . The above superior performance make it have important application potential in aerospace, shipbuilding, national defense and other fields . The bulk addition polymerization of aromatic compounds at high temperatures using compounds containing amino or hydroxyl groups as curing agent is usually the method to prepare phthalonitrile resin.…”