Aliphatic Polyester/polyhedral Oligomeric Silsesquioxanes Hybrid Networks via Copper‐free 1,3‐dipolar Cycloaddition Click Reaction

Abstract

In this study, we describe the preparation and characterization of a new class of thermoset hybrid networks containing aliphatic polyester and polyhedral oligomeric silsesquioxanes (POSS). The copper‐free 1,3‐dipolar cycloaddition click reaction of internal alkyne functionalized aliphatic polyester and multifunctional azido POSS with different concentrations led to highly crosslinked thermoset networks. The click reactions performed under ambient conditions (i.e., in tetrahydrofuran at room temperature for 1 day) in the absence of any catalyst. The chemical composition of hybrid networks and homogenous distribution of POSS molecules were confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy with energy dispersive spectroscopy. The swelling ratios of hybrid networks were commonly decreased by increasing POSS‐N3 content and by changing polar solvents to apolar solvents. Thermogravimetric analysis results demonstrated that the thermal stability of hybrid networks increased with higher POSS feeding ratio. Tensile tests were applied to evaluate the mechanical properties of hybrid networks. Compared to neat aliphatic polyester, the mechanical properties of hybrid networks significantly improved. For instance, the tensile strength were enhanced from 5 MPa to 19 MPa by increasing the concentration of azido functionalized POSS from 10 to 40. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2222–2227

The Use of Click-Type Reactions in the Preparation of Thermosets

“…The reaction continues at room temperature for several days [134]. These reactions have also been applied to the preparation of highly-crosslinked hybrid materials from azidated POSS and aliphatic polyesters with internal triple bonds [135,136]. The thermal and mechanical properties of hybrid networks were clearly enhanced by increasing the POSS-N 3 concentration.…”

Halloysite Containing Thermoset Nanocomposites via Free Radical Photocrosslinking Polymerization

“…Polymer nanocomposites can be prepared using various nanoparticles including 1D nanoclays [16] and graphene, [17] 2D carbon, [18] boron nitride [19] or halloysite nanotubes, [20][21][22] and 3D colloidal silica, [23] metal, [24] and POSS nanoparticles. [25][26][27][28][29][30] Numerous investigations have focused on carbon nanotubes (CNTs) and boron nitride nanotubes; both of these materials are technologically demanding to produce in bulk, making them expensive. The halloysite (HNT) is a natural tubular nanostructure composed of silica and alumina similar to kaolinite clay and resembles that of multiwalled CNTs.…”

Influence of POSS nanoparticles on the microstructure and mechanical properties of carbon fiber reinforced epoxy hybrid composites

“…[16][17][18][19][20][21][22][23] Among them, the POSS nanoparticles are three-dimensional, caged-shaped organosilicon compounds surrounded by functional groups that make them compatible with a polymer matrix. [24][25][26][27][28][29][30][31][32][33] The inclusion of POSS compounds as reinforcing materials into a polymer matrix not only markedly improves the mechanical (e.g., modulus, elasticity, strength, and rigidity) and thermal (e.g., thermal stability and transition temperatures) properties but also reduces the flammability, heat evolution, and viscosity during processing. [25,[31][32][33][34][35][36][37] Thus, they have been commonly used for the formation of functional hybrid composites.…”