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To solve the problems of low strength and high viscosity of room temperature vulcanized liquid silicone rubber, a series of terminated vinyl silicone oil were designed and synthesized, and low viscosity and high strength silicone rubber were prepared by the mechanical reinforcing agent. the results show that the molecular structure of the vinyl-terminated silicone oil has a significant effect on the mechanical properties and viscosity of the silicone rubber, and the best performance is found when the content of vinyl-terminated silicone oil is 0.16%. The low viscosity and high strength silicone rubber prepared from it was reinforced by vinyl MQ resin and fumed silica, which had a significant effect on improving the performance. Its tensile strength increased to 5.03 MPa, elongation at break to 338.90%, and tear strength to 7.15 kN/m compared to conventional silicone rubber, while the hardness increased to 43°. The viscosity is 34.9 Pa•s. The compression modulus is 7.48 MPa.

In this study, a kind of novel heat-insulating material composed by the vinyl-functionalized polyborosiloxane (BSiO) and hollow glass microspheres (HGM) was successfully prepared. Under solvent-free condition, the BSiO was synthesized by reacting triethoxyvinylsilane (VTEOS) and boric acid by one-pot method and characterized by GPC, FT-IR, NMR-29Si, NMR-11B and TGA analysis. The results indicated that the monomer feed ratio of the reactant made a great difference on the molecular structure and thermal stability of the BSiO and the BSiO-2 showed the best thermal stability when the feeding ratio of VTEOS and BA was 1.5. Moreover, the ceramic conversion analysis indicated that the BSiO-2 tended to form the inorganic SiBOC nanocomposite. Properties, such as the microstructure, density, linear shrinkage, compressive strength and thermal conductivity, burning behavior and flame retardancy of the BSiO-2/HGM composites after different heat treatment, were studied. The SEM results showed that the BSiO-2 could effectively wet the surface of HGM and the HGM was glued together firmly. With the increase in heat treatment temperature, the density and thermal conductivity of BSiO-2/HGM composites reached the minimum value at 600 °C, while the compressive strength reached the maximum value. The result of flame retardancy study showed that the composites possessed high LOI value (> 50%) and hardly any smoke could be observed during the burning process. This indicated that the BSiO-2/HGM composites possessed excellent flame-retardant property and fire safety. This paper will provide ideas for the design and preparation of heat-insulating materials with polyborosiloxane as heat-resistant binder.

The thermal and electrical conductivities of SR composites containing Cu-CFs and f-MWNTs were studied. The Cu-CFs and f-MWNTs were prepared by chemical deposition and the coupling method, respectiv...

In this investigation, 3-glycidoxypropyltrimethoxysilane and boric acid with the molar ratio of 1, 2, and 3 were used to synthesize different structures borosiloxane oligomers (BSiO-1, BSiO-2, and ...

The purpose of this study is to improve the interfacial adhesion property between epoxy resin (EP) and addition-curable liquid silicone rubber (AL-SR). A novel surface treatment agent, borosiloxane oligomers (BSiO), was synthesized, and the major chemical structure was evaluated by gel permeation chromatography, Fourier transform infrared spectra, nuclear magnetic resonance spectroscopy (29Si- and 11B-NMR), and thermogravimetric analysis. BSiO served as surface treatment agent for EP to improve interfacial adhesion characteristics of EP and AL-SR. The adhesion strength between EP and AL-SR was measured by pull-out test, and the results indicated that the adhesion strength increased from 0.02 MPa for EP/AL-SR to 0.18 MPa for BSiO-EP/AL-SR with the failure mode from EP posts dislodgement for EP/AL-SR to rubber breakage for BSiO-EP/AL-SR. Furthermore, adhesive mechanism was analyzed and concluded that the improvement of adhesion characteristics of EP/AL-SR through the oligomers surface treatment was a result of chemical and physical bonding. The BSiO acted as binder by reacting with amino groups on EP surface through the active epoxy groups and absorbing electron clouds of phenyl groups of AL-SR chains through the boron atoms. This feature makes BSiO a superior candidate to improve the adhesion and reduce the dislodgement or exfoliation of silicone rubber or other materials possessing electron-rich groups on the molecular chains from EP in the future.

In this study, a kind of boron-containg hybridized silicon rubber (VP–PBSi/SR), which possess great thermal and mechanical properties, was successfully prepared. First, the vinylphenyl-functionalized polyborosiloxane (VP–PBSi) possessing good storage stability were synthesized by reacting triethoxyvinylsilane (VTEOS), phenyltriethoxysilane (PTEOS) and boric acid (BA) by sol-gel method. From the results of GPC, FT-IR, 13C-, 29Si, 11B-NMR characterization, the structures of VP-PBSi were confirmed to be the cage structure. Then, the VP-PBSi/SR were prepared by in situ polymerization of vinylphenyl-functionalized polyborosiloxane (VP–PBSi) and addition liquid silicone rubber (SR). The effect of VP-PBSi on thermal stability and mechanical properties of SR were mainly discussed by scanning electron microscope (SEM), thermal gravimetric analysis (TG), universal testing machine, and dynamic mechanical analysis (DMA), respectively, and the results showed that the thermal stability and mechanical properties of the SR were significantly enhanced. The maximum thermal decomposition temperature (Tmax), char yield and tensile strength can reach 675 °C, 72.3% and 4.65 MPa, respectively, and 21.8%, 26.1% and 20.2% higher than that of neat SR. We believe this work can provide reference for the preparation of high-performance heat resistance rubber materials.

In this study, under solvent-free condition, the vinyl-functionalized polyborosiloxane (BSiOVi) was synthesized by reacting triethoxyvinylsilane (VTEOS) and boric acid (BA) and the chemical structures were characterized by GPC and FT-IR. The results indicated that the BSiOVi containg Si-O-B bonds and vinyl groups was successfully synthesized. Moreover, the thermal stability and compressive strength after heat treatment were studied. TG-DTG result indicated that the BSiOVi with more Si-O-B high energy bonds possessed the better thermal stability than that of silicone rubber only possessing Si-O-Si bonds. The results of mechanical property of BSiOVi showed that the BSiOVi after heat treatment possessed the higher compressive strength than that of silicone rubber. This is because that the polymerization of Si-CH=CH2 groups could improve the crosslinking density, and the ceramic transformation of BSiOVi after heat treatment tend to the formation of dense SiBOC nanocomposites. We believed that the BSiOVi could be effectively served high temperature resistant matrix resin for ceramic matrix.

A series of methyl-terminated and hydrogen-terminated hydrogen-containing silicone oil with different hydrogen content and chain length were synthesized by ring-opening polymerization design. Silicone rubber was prepared with hydrogen-containing silicone oil and vinyl-terminated silicone oil with a viscosity of 8033 mPa s. The silicone rubber was reinforced with vinyl MQ resin with a viscosity of 6223 mPa s and a vinyl content of 0.9%. Then the structure, thermal stability, viscosity of the synthesized hydrogenated silicone oil were characterized and the crosslinking density, mechanical properties, aging properties of the silicone rubber were analyzed. It was found that the mechanical properties of hydrogen-containing silicone oil with hydrogen content of 0.50% and chain length of 50% were the best. The parameters of silicone rubber were obtained as follows: viscosity 35.6 Pa s, tensile strength 5.05 MPa, elongation at break 339.01%, tear strength 7.23 kN/m, hardness 44°, compressive modulus 7.43 MPa. This provides an efficient method for designing high strength and low viscosity silicone rubber materials.

In this paper, (3-mercaptopropyl)trimethoxysilane (MPTS)- and copper-coated carbon fiber (M–Cu-CF) was obtained by electroless plating method. The M–Cu-CF was evaluated by FTIR, XRD, TGA, and SEM. It was found that the MPTS and Cu were coated on the fiber surface successfully. The M–Cu-CF was utilized as a conductive filler in silicone rubber (SR) for thermal and electrical conductivity applications and exhibited good dispersion and compatibility with the matrix. The effect of M–Cu-CF content on the thermal conductivity and volume resistivity of silicone rubber composites was investigated. The results showed that the thermal conductivity of the M–Cu-CF/SR composites reached 1.99 W (m K)−1 with only 4.0 wt% filler loading, approximately 2.10 times higher than that of raw-CF/SR composites at the same loading. And with the increase of M–Cu-CF loading, the least volume resistivity of M–Cu-CF/SR composites was 3.5 × 103 Ω cm.

Chemically coupling functionalization multi-walled carbon nanotube (MWCNTs)/nylon-6 (PA6) composites were prepared. The nanotubes were first treated by a volume ratio of 3:1 mixture of concentrated H2SO4/HNO3, and then the γ-aminopropyl-triethoxysilane (KH-550) was carried onto the surface of MWCNTs. Effect of MWCNTs coupling treatment on the mechanical and electrical properties of the MWCNTs/PA6 composites were investigated. The impact strength, tensile strength and modulus of p-MWCNTs (coupling process)/PA6 composites increase by 115.9%, 27.2% and 167.7%, respectively, compared with those of the pure nylon-6 resin. A significant increase of the electrical conductivity of the p-MWCNTs/PA6 composites with respect to the original-MWCNTs and a-MWCNTs/PA6 composites due to the increased compatibility with the matrix due to the formation of an inter face with stronger interconnections.

Electromagnetic microwave absorbing composite material containing magnetic Mn-Zn ferrite/conductive polyaniline nanocomposites introducing into epoxy resin were fabricated. The conductivity of the Mn-Zn ferrite/polyaniline nanocomposites were investigated by a four point probe method. Complex permeability and reflection loss of the Mn-Zn ferrite/conductive polyaniline/epoxy resin composites have been studied in the frequency of 30 MHz to 1 GHz. It has been found that the conductivity of the nanocomposites can be tailored by controlling the weight percentage of polyaniline. The complex permeability increased with the decreasing weight percent of polyaniline. The composite with the polyaniline weight percent of above 60.89 % can effectively broaden the absorbing band with minimum absorption of 5 dB about 500 MHz. It has also been found that the composite with the polyaniline weight percent of 28.12 % has a maximum absorption of 23 dB at about 700 MHz for a coating thickness of 2 mm. Therefore, the prepared composites can be potentially applied in electromagnetic absorbing field in the low frequency.

In this paper, we got Ni-MWNTs through pretreatment of MWNTs and electroless plating of nickel, and observed the Ni-MWNTs and MWNTs with TEM and FTIR. In addition, we prepared Ni-MWNTs/EP and MWNTs/EP composites. The volume resistivity、permittivity and permeability of composites were measured. Results showed that the volume resistivity of Ni-MWNTs/EP was higher than MWNTs/EP’s when volume fraction was lower than 8%. The ε" of Ni-MWNTs/EP was larger than MWNTs/EP’s. It indicated that Ni-MWNTs/EP had better electromagnetic energy storing and consumption capacity. And the permeability of Ni-MWNTs/EP would increase with the increasing of Ni-MWNTs. Ni-MWNTs/EP had some ferromagnetism.

According to piezoelectricity and electrical conductivity theory, the ternary system piezoelectric damping composites containing piezoelectric ceramic powder (PZT) / multi-walled carbon nanotubes (MWNTs) / epoxy resin (EP) were developed. Through the conductive and mechanical performance test of composites, the paper showed the piezoelectric damping energy dissipation mechanism of polymer composites. Results indicated that: the loss factor of materials would increase with the increasing of PZT content. When the content of PZT exceeded a certain value, tanδ would increase dramatically. When the content of MWNTs is 2%, tanδ reached a high value. This meant composites played the role of shock absorbing by conducting electricity from piezoelectric effect of PZT to external circuit.

In this paper, the polyaniline (PANI) coated multi-walled carbon nanotubes (MWNTs) was prepared in situ polymerization. Adding PANI/MWNTs into epoxy resin（EP）, we got PANI / MWNTs / EP composite microwave absorbing materials. Through testing permittivity 、permeability and reflection loss of materials, the paper showed the effect of PANI/MWNTS to the dielectrical and microwave absorbing properties of materials.The results showed： PANI/MWNTs had great effect on dielectrical and microwave absorbing properties of materials. But the imaginary permeability was close to 0. That indicated that it mainly consumed electromagnetic wave by dielectric loss. In 200-1000MHZ, materials had better absorbing property and lower reflection loss (-13.6).

This study showed the effect of Decabromodiphenylethane (DBDPE) - Sb2O3、Tetramomobisphenol A (BDDP) - Sb2O3 and Mg(OH)2 to the mechanical and retardant performance. To eliminate the bad influence of flame retardant agents to materials’ mechanical performance, SEBS-g-MAH and ABS-g-MAH were added into HIPS to toughen HIPS. The experimental results showed that Decabromodiphenylethane (DBDPE) - Sb2O3 had the best effect of flame retardant, and had little influence on the mechanical performance of HIPS. SEBS-g-MAH could improve the impact strength of HIPS greatly and had little influence on other performance.

In the present study magneto-polymer composite coatings are fabricated using nano Zn ferrite, Mn ferrite, Ni ferrite, Zn-Mn ferrite and Zn-Ni ferrite by spraying method. The complex permeabilities, Complex permittivities and microwave absorbing properties within the low frequency of these composites were characterized and investigated. The results showed that the magnetism of the mixed spinel ferrites ( Mn ferrite, Zn-Ni ferrite, Zn-Mn ferrite) are strong but the dielectric properties are weaker, while the magnetism of the normal spinel ferrites (Zn ferrite) is the weakest but provide with a big storage capability of electric energy. The absorbing characteristics of the spinel ferrites are better at 300 kHz-1.5GHz, with minimum absorption of 12.5 dB and the maximum absorption at 480MHz, 1050 MHz and 1400 MHz. The microwave absorbing property of the mixed spinel ferrite Zn-Mn ferrite is best having the RL value being -42.5 dB at 1400GHz.

This paper presents the design, development and characterization of the spinel ferrite [Mn0.2Zn0.8Fe2O4] powders and Nickel (Ni)-coated multiwall carbon nanotubes (MWNTs). A combination of Mn0.2Zn0.8Fe2O4 spinel ferrites particles and Nickel (Ni)-coated multiwall carbon nanotubes (MWNTs) were introduced into epoxy resin to be a microwave absorber. The structural characterizations and surface morphology of Mn0.2Zn0.8Fe2O4 and MWNTs were investigated by X-ray diffraction (XRD) and scanning electron microscopy respectively. The electromagnetic wave absorption characteristics of the composites have been studied in the frequency interval of 12-15GHz.The results for Mn0.2Zn0.8Fe2O4/EP, Mn0.2Zn0.8Fe2O4/MWNTs/EP and Mn0.2Zn0.8Fe2O4/Ni-coated MWNTs/EP microwave absorbers for the same thickness have been reported. It has been found that the Mn0.2Zn0.8Fe2O4/Ni-coated MWNTs/EP composites show the broadband characteristics with minimum absorption of 5 dB about 2.6 GHz and the maximum absorption of 37.05 dB at 14 GHz for a coating thickness of 2 mm. Therefore, Mn0.2Zn0.8Fe2O4/Ni-coated MWNTs/EP composites will be a suitable microwave absorptive material for 12-15GHz.

PPO was a better intensifier and charred material for High-impact polystyrene (HIPS), it could make HIPS achieve UL94V-0 with APP, MC, RDP. Especially, RDP not only improved the flame-retarded property but also controlled the hole producing, and had the best consistent with matrix which could improve the mechanical properties. SBS and SEBS were better consistent with matrix, especially SEBS was tiny granule, which could be dispersed in matrix easily. The properties of SEBS toughened the non-halogen flame-retarded HIPS was followed: tensile strength: 18.83MPa; izod notch impact strength: 15.7kJ/m2; UL94V-0.

A good method for dispersing Multi-walled carbon nanotubes (MWNTs) in LDPE matrix by melt processing technique had been developed. The surface of MWNTs was modified by HNO3, then, treated with γ-aminopropyltriethoxy Silane. The surface-modified MWNTs homogeneous LDPE composites with 0-0.35 mass fraction MWNTs loading had been evaluated for electrical conductivity. The composites’ electrical conductivity (σDC) was improved for the good dispersion of MWNTs in LDPE matrix. The values of σDC obeyed a percolation power law with MWNTs concentration threshold 0.10 mass fraction. 10-2 s/cm conductivity for 0.15 mass fraction MWNTs loading indicated that the composites could be used as lightweight electrostatic shielding materials.

To improve the thermal and mechanical properties of liquid silicone rubber (LSR) for application, the graphene oxide (GO) was proposed to reinforce the LSR. The GO was functionalized with triethoxyvinylsilane (TEVS) by dehydration reaction to improve the dispersion and compatibility in the matrix. The structure of the functionalized graphene oxide (TEVS-GO) was evaluated by Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDX). It was found that the TEVS was successfully grafted on the surface of GO. The TEVS-GO/LSR composites were prepared via in situ polymerization. The structure of the composites was verified by FTIR, XRD, and scanning electron microscopy (SEM). The thermal properties of the composites were characterized by TGA and thermal conductivity. The results showed that the 10% weight loss temperature (T10) increased 16.0°C with only 0.3 wt % addition of TEVS-GO and the thermal conductivity possessed a two-fold increase, compared to the pure LSR. Furthermore, the mechanical properties were studied and results revealed that the TEVS-GO/LSR composites with 0.3 wt % TEVS-GO displayed a 2.3-fold increase in tensile strength, a 2.79-fold enhancement in tear strength, and a 1.97-fold reinforcement in shear strength compared with the neat LSR. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42582.

In order to improve the mechanical properties and electrical conductivity of nylon-6 (PA6) composites, a highly effective multiscale structure filler comprising poly(diallyldimethylammonium chloride) (PDDA)-modified graphene and negatively surface-charged carbon fiber was synthesized in this study. For this, the graphene used a top-down method for synthesis by exfoliating graphite oxide (GO) through focused solar radiation on it and then modified its surface by using a polyelectrolyte. The carbon fiber (CF) surface was functionalized by an acid oxidation method. The multiscale structure was manufactured via the electrostatic interaction between the positively charged solar graphene (SG) and oppositely charged CF by homogeneous mixing. Scanning electron microscopy (SEM) images of the fracture surface of the PA6 composites exhibited that the carbon fiber/graphene multiscale structure possessed better dispersion and compatibility than those of individual CF and SG did. Thus, the impact strength, bending properties, and electrical conductivity of the PA6 composites were enhanced. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41968.

The synergetic effect of multiwalled carbon nanotubes (MWNTs) and carbon fibers (CFs) in enhancing the electrical conductivity of nylon 6 (PA6) composites was investigated. To improve the compatibility between the fillers and the PA6 resin, we grafted γ-aminopropyltriethoxy silane (KH-550) onto the MWNTs and CFs after carboxyl groups were generated on their surface by chemical oxidation with nitric acid. Fourier transform infrared spectroscopy and thermogravimetric analysis proved that the KH-550 molecules were successfully grafted onto the surface of the MWNTs and CFs. Scanning electron microscopy and optical microscopy showed that the obtained modified fillers reduced the aggregation of fillers and resulted in better dispersion and interfacial compatibility. We found that the electrical percolation threshold of the MWNT/PA6 and CF/PA6 composites occurred when the volume fraction of the fillers were 4 and 5%, respectively. The MWNT/CF hybrid-filler system exhibited a remarkable synergetic effect on the electrically conductive networks. The MWNT/7% CF hybrid-filler system appeared to show a second percolation when the MWNT volume fraction was above 4% and a volume resistivity reduction of two orders of magnitude compared with the MWNT/PA6 system. The mechanical properties of different types of PA6 composites with variation in the filler volume content were also studied. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40923.