Synthesis of eugenol-functionalized polyhedral oligomer silsesquioxane for low-k bismaleimide resin combined with excellent mechanical and thermal properties as well as its composite reinforced by silicon fiber

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 439; p. 135740
• Main Authors: Zhang, Zongwu, Zhou, Yijie, Cai, Lifeng, Xuan, Lixin, Wu, Xiao, Ma, Xiaoyan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2022
• Subjects: BD-type bismaleimide resin; Dielectric properties; Eugenol; Mechanical properties; POSS; Silica fiber; Thermal stability; Silica fiber; BD-type bismaleimide resin; Dielectric properties; Mechanical properties; POSS; Eugenol; Thermal stability
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.135740

[Display omitted] •A novel eugenol-functionalized and cage-like EG-POSS is synthesized.•EG-POSS is conducive to reduce dielectric constant and loss of BD resin.•The mechanical and thermal properties of BD resin are also improved.•Well-dispersed and covalently bonded Si-O-Si cages in resin led to enhancements. Introducing porous materials into resin matrix is effective to achieve low dielectric constant (low-k) value but challenge for simultaneously improving mechanical and thermal properties due to the heterogeneous dispersion of these fillers. Herein, a novel eugenol-functionalized cage-like (pore size, 1–2 nm) polyhedral oligomeric silsesquioxane (EG-POSS) was designed and synthesized, which exhibits excellent solubility and reactivity with BD-type bismaleimide resin. Thus, 4 wt% incorporated EG-POSS is uniformly dispersed in resin matrix and the resultant hybrid (BDEP-0.04) shows outstanding comprehensive performance, especially on dielectric, mechanical and thermal properties. Specifically, the dielectric constant (k) and loss (tan δ) at 1 MHz are reduced to 2.88 and 0.010 from 3.33 and 0.013. Meanwhile, the corresponding impact strength and flexural strength are improved to 18.75 KJ/m2 and 159.01 MPa, increased by 63.63 % and 27.29 %. In addition, BDEP-0.04 also exhibits the excellent thermal stability with glass transition temperature (Tg) of 290 °C, which is 8 °C higher than BD resin. Based on the lower k and tanδ value of BDEP-0.04 hybrid resin, as well as its better adhesion with silica fiber, the wave-transparent and mechanical properties of silica fiber reinforced composites (SF/BDEP-0.04) are further improved, showing that the wave transmission efficiency (94.2%), flexural strength (309.99 MPa), flexural modulus (15.70 GPa) and interlaminar shear strength (35.41 MPa) are all greatly higher than those of SF/BD. It’s concluded that EG-POSS is effective to optimize and balance the dielectric, mechanical and thermal properties of BD-type bismaleimide resin and SFs/BD composites, which is valuable for practical application in wave-transparent field.