Synthesis of (Hyper)Branched Monohydroxyl Alkoxysilane Oligomers toward Silanized Urethane Prepolymers

Abstract

The aim of this work was the synthesis of (hyper)branched oligomers based on trialkoxysilane in various conditions and further application of them in order to modify the urethane prepolymers. Hydroxyl-terminated trialkoxysilane was used as a monomer for homo-condensation. It was obtained by reaction of 3-aminopropyl trialkoxysilane (APTES) with ethylene carbonate (EC). The reaction was based on the attack of amine at the carbonyl carbon atom followed by ring opening of the carbonate to give a urethane (carbamate) product. The next step was the condensation via substitution of ethoxy groups on silicon atom with the terminal hydroxyalkyl groups present in the primary product with the evolution of ethanol. Accordingly, the impact of temperature and type of catalyst on process efficiency was investigated. A quantitative analysis of reaction progress and products of the conversion of EC together with ethanol evolution was conducted by means of gas chromatography, which allowed us to determine the formation of monomeric product and, indirectly, of oligomeric products. It was found that at room temperature after 24 h, the majority of the monomeric product was isolated, whereas at elevated temperature in the presence of Ti-based catalyst, further condensation of the monomer into branched oligomers was preferred, and, moreover, the application of vacuum intensified that process. The obtained products were structurally characterized by 1H and 29Si NMR, MALDI-ToF and Gel Permeation Chromatography. Finally, two different alkoxysilane products, monomeric and oligomeric, were applied for modification of urethane prepolymer, forming silanized one (SPUR). The influence of the silanizing agent on the mechanical and thermal properties of the moisture-cured products was shown before and after additional conditioning in water.

Critical Review on High-Safety Lithium-Ion Batteries Modified by Self-Terminated Oligomers with Hyperbranched Architectures

“…While some additives can improve battery safety, they may negatively affect battery performance, and an additive that has a positive effect on the anode may show negative effects on the cathode. Silicon polymers are a versatile cluster of materials that have been widely used in various applications due to their human friendliness and universal properties studied by Silicon polymers are a versatile cluster of materials that have been widely used in various applications due to their human friendliness and universal properties studied by Plichita et al [60]. 3-aminopropyl trialkoxysilane is a silicon-based chemical compound that is commonly used in industrial processes that produce siloxane compounds, silica nanoparticle compounds, or silane-containing particulates.…”

“…Batteries 2024, 10, x FOR PEER REVIEW 12 Plichita et al [60]. 3-aminopropyl trialkoxysilane is a silicon-based chemical compo that is commonly used in industrial processes that produce siloxane compounds, s nanoparticle compounds, or silane-containing particulates.…”