Fully Aromatic High Performance Thermoset via Sydnone–Alkyne Cycloaddition

Abstract

We have developed an efficient synthetic platform for the preparation of a new class of high performance thermosets based on the 1,3-dipolar cycloaddition of a bifunctional sydnone with a trifunctional alkyne. These processable materials possess outstanding thermal stability, with Td5% of 520 °C and a weight loss of <0.1% per day at 225 °C (both in air). Key to this performance is the stability of the starting functional groups that allows for reactive B-staging via simple thermal activation to give fully aromatic and highly cross-linked polypyrazole-based thermosets.

Branched phenyl‐s‐triazine moieties to enhance thermal properties of phthalonitrile thermosets

“…After washing with deionized water to neutral, the products, designated as b-PBP-Ph5, 8, 10, 12, 15, were obtained by suction filtration, followed by dehydration at 80 ∘ C in a vacuum oven overnight. 1…”

“…Growth in the aerospace, marine and microelectronic industries increasingly requires the development of heat-resistant materials. [1][2][3][4][5][6][7][8] Phthalonitrile (PN)-based resins, as a class of heat-resistant materials, have sparked great interest and attention, due to their unique properties, including outstanding thermal stability, great flame retardancy, low moisture resistance and excellent mechanical properties. [9][10][11][12][13][14] A factor that has impeded the application of neat PNs is their fairly sluggish curing condition.…”

Easily Processable Thermosets with Outstanding Performance via Smart Twisted Small‐Molecule Benzoxazines

“…The thermal expansion properties of poly( o HPMI‐ac) were measured by the use of TMA (see Figure S9, Supporting Information, for the TMA curve of poly( o HPNI‐ac) film). The coefficient of thermal expansion (CTE) was found to be 27.4 ppm °C −1 in the temperature range of 25–350 °C, which is much lower than other reported polymers, such as polyimides, polybenzoxazines, and even very high‐performance fully aromatic thermosets based on sydnone–alkyne cycloaddition 2a,23. Such a low CTE value is beneficial for the design of substrate materials for electronic packing 24…”

“…High‐performance polymers with high thermal stability and excellent mechanical properties have been now widely applied in aerospace, electrical insulation, and ballistic industries 1. Among the many well‐known polymeric materials, thermosetting polymers, as densely cross‐linked networks of repeating organic units, play important roles in the fields of advanced materials due to thermal, mechanical, chemical, and electrical properties 2. However, high‐performance thermosets generally suffer from the inherent shortcomings such as poor processability, high polymerization temperature, and brittleness of the resulting cross‐linked polymers, and none of the commonly used commercial thermoset polymers, for example, epoxies,3 phenolics,4 polyimides,5 and bismaleimides,6 possesses all of the desired properties.…”

Recyclable Cu(II)‐Coordination Crosslinked Poly(benzimidazolyl pyridine)s as High‐Performance Polymers

“…High-performance polymers have attracted great interest of many research groups and have been widely used in many areas, such as aerospace, machinery, electronics, etc., due to their excellent heat resistance, good chemical stability, and outstanding mechanical performance. [1][2][3][4][5][6][7][8][9][10] In the last several decades, much attention has been focused on developing various synthetic strategies for preparing polymers with good processability and improved mechanical properties. [7,[11][12][13][14][15] Among the examples reported, chemical crosslinking has been proved to be an effective manner to enhance the thermal stability and mechanical strength of polymers.…”