Procuring silicone rubber composite with different content of vinyl MQ silicone resin was prepared and its thermal stability was evaluated. A total of 50 wt% MQ resin containing 5 wt% vinyl MQ exhibited optimal thermal stability and was consequently chosen. This silicone rubber composite was blended with TPU at high temperature using an internal mixer to produce a modified TPU. The TPU modified by silicone rubber was firstly investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). The FTIR results indicated that negligible chemical reactions occurred between TPU and silicone rubber during the mixing process. Furthermore, the TGA results demonstrated that the silicone rubber composite positively influenced the thermal stability of TPU. Additionally, the modified TPU displayed satisfactory thermal stability even after aging. Moreover, Scanning Electron Microscope (SEM) results indicated that uniform dispersion of silicone rubber was facilitated by the banburying method. The tensile strength of modified TPU initially increased and then decreased when the content of silicone rubber reached 3 wt%. On the other hand, the elongation at break of modified TPU demonstrated continuous improvement. Furthermore, the mechanical properties of the modified TPU were still acceptable after aging.
Bare conductors were widely used in the early power distribution system. However, without an insulation layer, it can pose unexpected safety issues. To solve this problem in an effective and economical way, on-site insulating the bare conductors is highly desirable. Unlike the traditional silicone insulating material loaded with high content of inorganic fillers, silicone material reinforced by MQ resin has suitable viscosity to satisfy the requirement of on-site insulating. Benefiting from MQ resin, the formula proposed has excellent mechanical, electrical, and aging properties. It can be observed that the presence of MQ resin is beneficial for mechanical properties because of its core-shell double-layer spherical structure. Furthermore, owing to this special structure, it improves the dispersion of alumina trihydrate (ATH) and enhances the electrical properties of the composites. Although the presence of MQ resin may lead to a slightly negative effect on the thermal property, it can greatly improve flame retardancy by the compounding of a novel Pt catalyst system and ATH. As for the hydrothermal aging performance, the elongation at break of the sample is greatly improved by the addition of MQ resin. Meanwhile, a feasible measure is also proposed to solve the lightning-induced breakage problem of insulated conductors. The results of this article are helpful for the investigation and application of on-site insulating material for bare conductors.
Yu Zhou,Zuyi Zhao,Zhaoxia Liu,Hongxiang Chen,Hongye Yan,Junjie Tan,Fan Li
In order to improve the curing efficiency and reduce energy consumption of silicone pressure-sensitive adhesive (SiPSA), a kind of UV-curable SiPSA based on thiol-ene reaction was prepared with methyl vinyl MQ resin as hard segment, methyl vinyl silicone rubber (110-2S) as soft segment and mercaptyl silicone oil as cross-linker. The UV-cured SiPSA exhibited excellent thermal stability and water resistance. Its physical features such as chemical composition, cross-linking extent and dispersion of MQ resin in silicone rubber were directly related to the vinyl content in MQ resin, the thiol/ene ratio and the resin/rubber ratio, which further affected mechanical properties and adhesive properties of SiPSA. With the vinyl content in MQ resin of 56 mmol/100 g, the thiol/ene molar ratio of 0.8 and the resin/rubber mass ratio of 1.4, the UV-cured SiPSA-B1.4–0.8 had better mechanical properties, moreover it had higher tensile shear strength of >2.0 MPa and showed interface failure on the surface of substrates, indicating that it had great potential applications as PSA.
危险品化学品经营许可证（带存储）