Shuang Xu

Bio: Shuang Xu is an academic researcher from Northwestern Polytechnical University. The author has contributed to research in topics: Cyanate ester & Epoxy. The author has an hindex of 4, co-authored 8 publications receiving 216 citations.

Hyperbranched polyborosilazane and boron nitride modified cyanate ester composite with low dielectric loss and desirable thermal conductivity

Abstract: In this paper, we presented a new strategy for fabrication of polymeric composites combined with low dielectric loss and desirable thermal conductivity. With the incorporation of hyperbranched polyborosilazane (hb-PBSZ) into bisphenol A cyanate ester (BADCy) matrix, the modified hb-PBSZ/BADCy resin with 4 wt% hb-PBSZ possessed a low dielectric constant (a) value of 2.37 and relatively low dielectric loss tangent value of 0.008 at 1MHz. Furthermore, by integrating micrometer boron nitride particles (mBN) into hb-PBSZ/BADCy matrix, the mBN/hb-PBSZ/BADCy composites presented relatively low a of 3.09, desirable thermally conductive coefficient (λ of 0.63 W/(m·K)) and thermal diffusivity (α of 0.42 mm2/s) values. It provides an important perspective for designing dielectric and thermally conductive polymeric composites for electrical packaging and energy storage fields.

Fabrication of novel wave-transparent HMPBO fibre/BADCy laminated composites

Abstract: The method of “impregnation–winding–lamination–mould pressing” was performed to fabricate novel wave-transparent high modulus poly(p-phenylene-2,6-benzobisoxazole) fibre/bisphenol A cyanate ester resin (HMPBO fibre/BADCy) laminated composites. The “two-step approach” of methanesulfonic acid/γ-glycidoxy propyl trimethoxy silane (MSA/KH-560) was also proposed to functionalize the HMPBO fibres’ surface. Results revealed that KH-560 was grafted on the HMPBO fibres’ surface successfully. The functionalized HMPBO fibre/BADCy laminated composites possessed better ILSS & flexural strength, lower e & tan δ, and higher heat-resistance index & Tg. The ILSS and flexural strength of the functionalized HMPBO/BADCy laminated composites were increased to 53.7 MPa and 753.7 MPa, respectively. The corresponding e and tan δ were decreased to 2.93 and 0.00097, respectively. The corresponding heat-resistance index and Tg were increased to 219 °C and 236 °C, respectively. The functionalized HMPBO fibre/BADCy laminated composites display potential application in radomes and the antenna systems of aircrafts.

Modified PBO fiber/cyanate ester resin wave-transparent composite material and preparation method thereof

Abstract: The invention provides a modified PBO fiber/cyanate ester resin wave-transparent composite material and a preparation method thereof. A PBO fiber, high in strength and modulus and low in dielectric constant, is taken as a reinforcement, and a cyanate ester resin modified by an epoxy resin is taken as a substrate. The prepared modified PBO fiber/cyanate ester resin wave-transparent composite material not only is high in bending strength and interlaminar shear strength, but also has multiple characteristics of low dielectric constant and high temperature resistance.

Significantly enhanced and precisely modeled thermal conductivity in polyimide nanocomposites with chemically modified graphene via in situ polymerization and electrospinning-hot press technology

Abstract: Both aminopropylisobutyl polyhedral oligomeric silsesquioxane (NH2-POSS) and hydrazine monohydrate were utilized to functionalize graphene oxide (GO), and to obtain chemically modified graphene (CMG), which was then used for preparing thermally conductive CMG/polyimide (CMG/PI) nanocomposites via a sequential in situ polymerization and electrospinning-hot press technology NH2-POSS molecules were grafted on the GO surface, and CMG was obtained by the reaction between NH2-POSS and GO The thermal conductivity coefficient (λ), glass transition temperature (Tg) and heat resistance index (THRI) of the prepared CMG/PI nanocomposites were all increased with increasing the CMG loading The λ value of the CMG/PI nanocomposites with 5 wt% CMG was significantly improved to 105 W m−1 K−1, about 4 times higher than that of the pristine PI matrix (028 W m−1 K−1) The corresponding Tg and THRI values were also increased to 2130 and 2823 °C, respectively Moreover, an improved thermal conductivity model was proposed and predicted the λ values of the nanocomposites more precisely than those obtained from the typical Maxwell, Russell and Bruggemen classical models

Dual modification of graphene by polymeric flame retardant and Ni(OH)2 nanosheets for improving flame retardancy of polypropylene

Abstract: To improve its dispersion and flame retardant efficiency, graphene oxide (GO) is dually modified with polymeric flame retardant and the nanomaterial with catalytic carbonation ability. Via the reactions between oxygen functional groups in GO and P Cl groups in hexachlorocyclotriphosphazene, phosphazene-based flame retardant is grafted to GO. Due to the strong affinity of Ni 2+ with NH 2 groups in this phosphazene flame retardant, the decoration of Ni(OH) 2 nanosheets on the graphene is facilitated. Transmission electron microscopy images confirm good dispersion and exfoliation state of graphene in polypropylene (PP) matrix. The incorporation of functionalized graphene oxide (FGO) results in the reduction of peak heat release rate, total heat release and smoke release of PP during the combustion. Flame mechanism of FGO is concluded according to the results of thermal decomposition and char analysis. This work provides a novel modification strategy for enhancing the dispersion and flame retardant efficiency of graphene.