Highly Thermally Stable, Reversible, and Flexible Main Chain Type Benzoxazine Hybrid Incorporating Both Polydimethylsiloxane and Double‐Decker Shaped Polyhedral Silsesquioxane Units through Diels–Alder Reaction

Abstract

This work synthesizes a new bifunctional furan derivative (PDMS‐FBZ) through a sequence of hydrosilylation of nadic anhydride (ND) with polydimethylsiloxane (PDMS), reaction of the product with p‐aminophenol to form PDMS‐ND‐OH, and its subsequent Mannich reaction with furfurylamine and CH2O. Then, the main chain‐type copolymer PDMS‐DABZ‐DDSQ is prepared through a Diels–Alder (DA) cycloaddition of PDMS‐FBZ with the bismaleimide‐functionalized double‐decker silsesquioxane derivative DDSQ‐BMI. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy confirm the structure of this PDMS‐DABZ‐DDSQ copolymer; differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA) reveal it to have high flexibility and high thermal stability (Tg = 177 °C; Td10 = 441 °C; char yield = 60.1 wt%); contact angle measurements reveal a low surface free energy (18.18 mJ m−2) after thermal ring‐opening polymerization, because the inorganic PDMS and DDSQ units are dispersed well, as revealed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). This PDMS‐DABZ‐DDSQ copolymer possesses reversible properties arising from the DA and retro‐DA reactions, suggesting its possible application as a functional high‐performance material.

Synergistic Self-Healing Enhancement in Multifunctional Silicone Elastomers and Their Application in Smart Materials

“…DA and rDA reactions in a system composed of polysiloxanes (Mn~13,000 g mol −1 ) grafted with maleimidocarboxyphenyl units (3–4 mol%) and POSS with eight furan moieties (maleimide:furan mole ratio of 1:3.5) occurred at 50 °C and 110 °C, respectively [ 25 ]. Bifunctional furan end-grafted PDMS was crosslinked with bismaleimide-functionalized double-decker silsesquioxane (DDSQ-BMI) ( Scheme 3 ) [ 26 ]. Thermally stable product ( T d10 = 441 °C; char yield = 60.1 wt.%) of low surface free energy (18.18 mJ m −2 ) was flexible enough ( T g = 177 °C) to undergo a DA/rDA reaction.…”

Enhanced thermal and porous properties of double-decker-shaped polyhedral silsesquioxane-bismaleimide (DDSQ-BMI) nanocomposites for high-performance CO2 storage and supercapacitors

“…30–33 In pursuit of improved thermal properties for BMI derivatives, in our previous study, we proposed the incorporation of inorganic nanoparticles such as double-decker-shaped polyhedral silsesquioxane ( DDSQ ). 34 In polymer/ DDSQ or polymer/POSS hybrids, 35–46 there is high thermal stability because of their intrinsic inorganic cage structure, which can increase the thermal decomposition temperatures of BMI resins using physical dispersion or chemical covalent bonding.…”

Hybrid Porous Polymers Combination of Octavinylsilsesquioxane/Pyrene with Benzothiadiazole Units for Robust Energy Storage and Efficient Photocatalytic Hydrogen Production from Water

“…A developed porous material, based on polyhedral oligomeric silsesquioxanes (POSS), demonstrates variable properties and a highly symmetrical three-dimensional structure with specified nanometer-sized dimensions. − Its potential lies in the combination of versatile and flexible organic shells surrounding a rigid silica core. It is a promising candidate for synthesizing hybrid nanocomposites that exhibit properties midway between organics and ceramics, − The increasing demand for POSS in scientific research and industry is attributed to their customizable physical and chemical properties. − Another crucial aspect of functionalized silsesquioxanes is their physicochemical properties arising from their hybrid (organic–inorganic) nature. − The Si–O–Si framework, corresponding to silica with a well-defined structure, could serve as an intriguing material for modifying polymers and acting as fillers (nanofillers). − The precise control of molecule sizes and the variation in functional groups within the POSS core allow for their accurate deposition and embedding in a polymer matrix. − This, in turn, results in the creation of composite materials with unique characteristics. These organic–inorganic hybrid materials showcase a diverse range of fascinating physicochemical properties, including alterations in solubility, enhanced dielectric characteristics, improved resistance to oxidation and fire, elevated decomposition and glass transition temperatures, reduced heat transfer rates, and an impact on the hardness of the resulting materials. − …”