Synthesis and thermal stability properties of boron‐doped silicone resin

Abstract

In this article, a novel boron‐doped silicone resin (BSR) was synthesized by hydrolysis‐polycondensation method, with propyl‐triethoxysilane (PTES), dimethyl‐diethoxysilane (DMDES), and boric acid (BA) as starting materials, using absolute ethyl alcohol as solvent and hydrochloric acid as catalyst. The structures of the BSR were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), X‐ray photoelectron spectroscopy (XPS), and gel permeation chromatography (GPC). FTIR spectra showed characteristic BOSi and SiOSi stretching modes. XPS and NMR results confirmed further that boron element was doped successfully into the main chains of the silicone resin as SiOB bond motifs, and hydroxyl groups from BA were condensed properly with SiOH or SiOR to form cross‐linked structure of BSR with narrowed molecular weight distributions in optimum experimental condition. The thermal stability of the BSR was studied by thermogravimetry analysis and derivative thermogravimetry. The thermal degradation temperature of the silicone resin improved greatly after doping element boron into the main chain, and the thermal stability of the BSR was influenced by the content of boron. The thermal degradation mechanism of this BSR was also discussed. The degradation process can be divided into two stages, the weight loss in the first stages may be corresponding to the loss of the small groups and weaker bonds in the chains, such as CH3, and C3H7, the weight loss in the second stage may be corresponding to the loss of the group as OC2H5. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40934.

Synergistic effects of boron-doped silicone resin and a layered double hydroxide modified with sodium dodecyl benzenesulfonate for enhancing the flame retardancy of polycarbonate

“…33 In the spectrum of DBS-LDH, the characteristic peak at 3490 cm À1 is assigned to the stretching vibrations of the -OH groups attached to Al and Mg ions in the layers. 30 The sulfonate stretching bands occur at 1180 cm À1 and 1040 cm À1 , 34 con-rming the exchange of DBS ions in the interlayer space of LDH (consistent with the results of XRD), as shown in Scheme 1. In the spectrum of DBS-LDH/BSR, the peak at 3490 cm À1 (O-H) is broader than that of DBS-LDH, indicating a slight reduction in the number of hydroxyl groups.…”

“…Thus, it can provide evidence for the intercalation of DBS ions into the interlayer galleries to increase the interlayer spacing (2.9 nm). 30,39 Furthermore, the dispersion of DBS-LDH in the polymer has greatly improved over that of the unmodi-ed LDH. 11 The thickness of NO 3 -LDH has been reported to be 0.48 nm, and the distance between layers is 2.42 nm, which is nearly identical to the length of the DBS molecular chain (approximately 2.1 nm).…”

Effect of Surface Modification on Mechanical Properties of Quartz Fiber Reinforced Boron Doped Silicone Resin Composites

“…[37,38] The second endothermic peaks of Qf/BSR at 539°C and Qf/BSR-KH550 at around 633°C are attributed to the mineralization reactions take place with the hemolytic cleavage of C-H and Si-C bonds and the formation of H 2 and CH 4 , accompanied by the thermal degradation of Si-O-Si and Si-O-B bonds of the main chains. [39,40] The sizing agent of KH550 on the quartz fiber increases the thermal decomposition temperature of Qf/BSR-KH550 composites significantly.…”

Thermal Stability of Modified Insulation Paper Cellulose Based on Molecular Dynamics Simulation

“…Thus, the thermal stability of the Si-O bond is better than that of the C-C bond. The length of the Si-O-Si bond is also longer (0.164 nm), and its bond angle is larger (140-180 • ) [36]. The chain structure of polysiloxane is very soft, the interaction between chains is weak, and its surface tension is low, which means that polysiloxane can still maintain its original performance in a wide range of temperatures.…”