Mechanical Blending Method Research Articles

Study on high‐temperature composite properties of fluorosilicone rubber with nano‐Sb2O3

AbstractThis article studied the influence of nano‐Sb2O3 on the high‐temperature composite performance of fluorosilicone rubber (FVMQ). FVMQ with 4% mass of nano‐Sb2O3 content was prepared by mechanical blending method. The friction properties of FVMQ and Sb2O3/FVMQ composites at different temperatures were analyzed by means of three‐dimensional profilometer and scanning electron microscopy. The results showed that nano‐Sb2O3 can enhance the matrix strength of FVMQ, and this effect was obvious at high temperature. The elongation of Sb2O3/FVMQ composites was increased by 10.7% at 25°C. The tear strength of Sb2O3/FVMQ composites was increased by 53.1%. While the friction coefficient and the wear amount, respectively, were decreased by 20 and 48.53% at 200°C. Sb2O3/FVMQ composite showed excellent anti‐wear, antifriction, anti‐tear, and other characteristics in the high‐temperature test. The enhancement of the cross‐linking density of matrix caused by adding Sb2O3 into FVMQ can lead to the softening of rubber, and the type of wear changed from abrasive wear to adhesive wear. Thus, the composite showed good wear resistance.

Acrylonitrile–butadiene rubber reinforced by graphene oxide/halloysite nanotubes hybrid nanofillers through mechanical blending method

ABSTRACTWith the idea of improving the mechanical properties of acrylonitrile–butadiene rubber (NBR) for potential industrial application, hybrid nanofillers prepared by hybridizing graphene oxide (GO) with halloysite nanotubes (HNT), were incorporated through mechanical blending to reinforce NBR. Graphene oxide/halloysite nanotubes (GH) hybrid filler demonstrates significant synergetic reinforcement effect in mechanical properties of NBR. The substantial improvement in mechanical properties is attributed to the uniform dispersion of hybrid filler in the matrix and to the strong interaction between the hybrid filler and matrix. Scanning electron microscopy images obtained from the fractured surface of GH-reinforced NBR composites showed more uniform dispersion with less agglomerations and cracks than that of GO and HNT. The strong interaction between the hybrid filler and NBR was confirmed by the increase of glass transition temperature, storage modulus and crosslinking density.

Improving thermal and mechanical properties of the alumina filled silicone rubber composite by incorporating carbon nanotubes

Carbon nanotubes (CNTs) can be used to improve the thermal and mechanical properties of composites owing to their excellent characteristics. Methyl vinyl silicone rubber matrix composites filled with alumina (Al2O3) powder and CNTs were fabricated through a conventional mechanical blending method. The effects of the mass fraction, surface modification of Al2O3 powder and the addition of CNTs on the thermal conductivity, Young's modulus and hardness of the composites were investigated. Results show that a higher mass fraction of the Al2O3 powder results in a higher thermal conductivity of the composites. When the mass fraction of Al2O3 powder is fixed, the thermal conductivity, Young's modulus and hardness of the composites are improved obviously by surface modification of Al2O3 powder and adding a small amount of CNTs. The combination of the modified Al2O3 filler and CNTs filler can synergistically enhance the interfacial interaction between the fillers and rubber matrix by the formation of better heat conduction channels and network structures in the rubber matrix, thereby improving the thermal conductivity and mechanical properties of the composites.

Improvement in mechanical properties of NBR/AO60/MMT composites by surface hydrogen bond

AbstractIt is still a challenge to prepare high performance rubber/MMT composites by one‐pot method without solution. In this work, NBR/AO60/montmorillonite (MMT) (NBR/AM) composites were prepared by mechanical blending method and in‐situ formation of surface hydrogen bond was introduced under vulcanization process. Results showed that the polar parts of melting AO60 could partly intercalate into interlayer of MMT and some parts of melting AO60 molecules were absorbed onto surfaces of MMT particles during the vulcanization process. Subsequently, surface hydrogen bonds were constructed among NBR, AO60, and MMT after natural cooling, as evidenced by FTIR, resulting in more complex morphology and good interfacial adhesion in the NBR/AM composite. Consequently, as compared to NBR/montmorillonite (NBR/M) composite, remarkable improvements were found in mechanical properties and energy dissipation at high temperature of NBR/AM composite, which may provide a new prospect for designing high performance damping materials.

X-band shielding of electromagnetic interference (EMI) by Co2Y barium hexaferrite, bismuth copper titanate (BCTO), and polyaniline (PANI) composite

Co2Y/BCTO/PANI composite was synthesized using mechanical blending method. The XRD analysis shows that the composite exhibit pure phase of Co2Y barium hexaferrite and bismuth copper titanate (BCTO) which is also supported by Raman analysis. Resonance occurs over the whole frequency region in the spectra of Co2Y/BCTO/PANI composite with dielectric losses dominating the lower frequency region due to interfacial polarization and magnetic losses dominating the higher frequency region as a result of eddy current losses, natural and exchange resonance. The observed values of shielding effectiveness for reflection are higher than those of shielding effectiveness for absorption, this indicates that most of the incident EM wave is reflected rather than absorbed. The Co2Y/BCTO/PANI composite shows total shielding effectiveness value above 20 dB with maximum total shielding effectiveness value of 31.97 dB at 10.30 GHz and matching thickness of 2 mm. The high value of total shielding effectiveness is attributed to good impedance matching between the components of the Co2Y/BCTO/PANI composite as well as higher dielectric losses as compared to magnetic loses.

Synthesis and characterisation of superhydrophobic CNC/ZnO nanocomposites by using stearic acid

The synthesis of superhydrophobic materials by using inorganic materials and organic renewable materials is a hot topic in academic research. At present, the methods used to prepare superhydrophobic composites are complicated and the hydrophobic modifiers used are expensive. The authors report a simple and efficient method for the synthesis of superhydrophobic composites. At the beginning, the cellulose nanocrystal (CNC)/ZnO nanocomposites were prepared by mechanical blending method, and the surface micro–nano rough structure was constructed. Then the superhydrophobic CNC/ZnO nanocomposites were obtained by hydrophobic modification with cheap low surface energy substance. The results demonstrate that the inorganic–organic nanocomposites have excellent superhydrophobic properties, which indicates that the inorganic–organic nanocomposites have potential applications as hydrophobic additives in coatings and other fields.

Effect of Nanometer Antimony Trioxide on Properties of Flame Retardant Polypropylene Matrix Composites

Using antimony trioxide nanoparticles (nano-Sb2O3), montmorillonite (MMT) and brominated polystyrene (BPS) as additive and using polypropylene (PP) as matrix material, a novel nano-Sb2O3/MMT/BPS-PP flame retardant composite was synthesized via mechanical ball milling dispersion and melt blending method and characterized by X-ray diffraction, scanning electron microscopy, differential scanning calorimeter and tensile properties testing. The flame retardant performance of the composite was investigated by limiting oxygen index and vertical burning test (UL-94). The results show that the mechanical properties and flame retardant properties of the composites are improved compared to that of pure PP when PP matrix retardant composites are added with different mass fraction of nano-Sb2O3. When the mass fraction of nano-Sb2O3 is 3wt%, the PP matrix composite exhibits excellent tensile strength and crystallization properties. When the mass fraction of nano-Sb2O3 is more than 3wt%, the PP matrix composite exhibits excellent flame retardancy.

Improved mechanical and antibacterial properties of silver-graphene oxide hybrid/polylactid acid composites by in-situ polymerization

Mechanical and antibacterial properties of polylactid acid have to be improved for advanced applications of medical instruments, artificial tissues and active packaging, etc. In this work, antibacterial polylactid acid nanocomposites are developed by using silver-graphene oxide hybrid (Ag@GO) as filler via in-situ polymerization and direct mechanical blending method, respectively. The effects of Ag@GO content and preparation method on the mechanical and antibacterial properties of the polylactid acid nanocomposites are investigated. It is shown that the flexural strength of the Ag@GO/polylactid acid nanocomposites increases from 326 to 942 K Pa as the Ag@GO content increases from 0 to 2.0 wt.%; the antibacterial rate (to Escherichia coli ATCC 25,922 and Staphylococcus aureus ATCC 6538) increases from 0 to 99% as the Ag@GO content increases to 2.0 wt.%. Further, the flexural strength and antibacterial properties of the composites prepared by the in-situ polymerization method are greatly improved and are consistently higher than those of the composite counterparts prepared by the direct mechanical blending method.

Preparation and Properties Analysis of Chlorinated Butyl Rubber (CIIR)/Organic Diatomite Damping Composites.

In this work, a novel type of diatomite was prepared with a limited content of hindered phenol groups grafted on its hydrophobic surface. The obtained samples were characterized for their surface groups, particle morphology, pore structure, and thermal behaviors. Then, modified diatomite (MDT) was used in preparation of reinforced chlorinated butyl rubber (CIIR) composites by mechanical blending method. The powder of MDT can be uniformly dispersed in CIIR matrices and the compatibility was good. In addition, the MDT showed a positive effect on damping performance of CIIR composites. A blending ratio of CIIR/MDT = 100/10 presented the best damping performance and the damping temperature range (tan δ > 0.7) was extended from 60 to 70 °C. The variable temperature FTIR spectra showed the presence of hydrogen bonds between the hydroxyl groups and chloride atoms in the CIIR matrices, and a blue shift exhibited when these hydrogen bonds were dissociated. Hence, these CIIR composites provided good damping behaviors and supplied a novel and promising way for preparation of high damping rubber composites with broad temperature ranges.

Ultrafine portland cement performance

By mixing several binder materials and additions with different degrees of fineness, the packing density of the final product may be improved. In this work, ultrafine cement and silica fume mixes were studied to optimize the properties of cement-based materials. This research was performed in mortars made of two types of cement (ultrafine Portland cement and common Portland cement) and two types of silica fume with different particle-size distributions. Two Portland cement replacement ratios of 4% and 10% of silica fume were selected and added by means of a mechanical blending method. The results revealed that the effect of the finer silica fume mixed with the coarse cement enhances the mechanical properties and pore structure refinement at a later age. This improvement is somewhat lower in the case of ultrafine cement with silica fume.

Plasma induced surface coating on carbon nanotube bundles to fabricate natural rubber nanocomposites

Carbon nanotube bundles (CNTB) with one-dimensional orientation arrangement structure were grafted a layer of polyacrylic acid (PAA) through plasma induced polymer grafting in this study. Thus, we blended these modified CNTB (CNTB-PAA) into natural rubber (NR) matrix through the silane in-situ modification-dispersion technique achieved by mechanical blending method. In this process, carboxyl groups in large quantities distributed in the surface of CNTB-PAA could be subjected to dealcoholization reaction with silicon hydroxyl (Si-OH) generated from the hydrolysis of silane coupling agent (Si69), and a single sulfur bond of Si69, meanwhile, could participate in the curing reaction of rubber. The ultimate nanocomposites had a significantly decreased network effect of fillers and an improved interfacial bonding between CNTB and rubber matrix. The tensile and dynamic-mechanical tests revealed a strong enhancement in the tensile stress and a marked reduction in the dynamic hysteresis loss of the nanocomposites.

Modified-diatomite reinforced rubbers

A novel diatomite, produced by Heihe in Heilongjiang Province of China, has been modified by high temperature treatment and ultrasonic dispersion technology with different modifiers to fill various rubbers. The modified-diatomite reinforced rubber composites were obtained successfully by mechanical blending method. According to the mechanical properties test and SEM analysis, the most suitable diatomite reinforced rubbers were fluorine rubber, EPDM rubber and acrylate rubber, and the diatomite can replace silica to reinforce and fill these three kinds of rubbers.

Mechanical and Thermal Properties of Unsaturated Polyester/Vinyl Ester Blends Cured at Room Temperature

Unsaturated polyester (UP) resin containing aromatic ring was blended with vinyl ester (VE) at wide range composition (10, 20, 30, 40,and 80 wt.%) using mechanical blending method. The blends were cured at room temperature using methyl ethyl ketone peroxide (MEKP) (4 wt.%) as catalyst initiator without the presence of catalystaccelerator. The effect of vinyl ester composition on theenhancement of mechanical and thermal properties of unsaturated polyester/vinyl ester blends was investigated. The polymer blends were characterized by Fourier Transform Infra Red (FTIR)spectroscopy, tensile testing, hardness testing, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). IR spectra showed UP and VE peaks. The curing copolymerization reactionoccurred at vinyl (C=C) bonds. The addition of vinyl esters enhanced mechanical and thermal properties. The UP/VE blends showed homogeneous morphology, transparent and copolymer thermoset blend.

Study on damping properties of HVBR/EVM blends prepared by in situ polymerization

In comparison with normal damping rubbers such as natural rubber (NR), styrene butadiene rubber (SBR), isobutylene isoprene rubber (IIR) etc., Mo-based high vinyl polybutadiene rubber (HVBR) with high loss factor, excellent aging resistance and glass transition temperature closer to room temperature, is a promising damping material. The effective damping temperature range of HVBR could be further broadened by blending with ethylene-vinyl acetate (EVM) and the effects of blending methods (in situ polymerization blending or mechanical blending) and blending ratios on the damping properties and physical properties of HVBR/EVM blended rubber were studied. HVBR/EVM in situ polymerization blends was prepared by butadiene coordination polymerization by Mo-base catalyst in a toluene solution of EVM. The results of dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM) of the blended vulcanizates via in situ polymerization blending revealed that the compatibility between HVBR and EVM was improved compared with that of the blended vulcanizates via the traditional mechanical blending method. The two phases of HVBR/EVM in situ polymerization blends had good dispersion and uniformity, the damping temperature range was significantly expanded, and the peak and valley of the damping temperature range were greatly improved. A blending ratio of HVBR/EVM900 = 100/40 showed the best damping properties and the effective damping temperature range (tanδ>0.3) was extended from −6.6 °C to 39.4 °C.

Influences of interfacial adhesion on gas barrier property of functionalized graphene oxide/ultra-high-molecular-weight polyethylene composites with segregated structure

The segregated graphene oxide(GO)/ultra-high-molecular-weight polyethylene (UHMWPE) composite films with various interfacial adhesion property were prepared by mechanical blending method from UHMWPE, GO, dodecyl amine (DA) functionalized graphene oxide(DA–GO) or uniform DA–GO/high density polyethylene (DA–GO/HDPE) powder. The results of XRD and XPS indicated that DA chain was successfully grafted onto GO sheets via a chemical method, which enhanced the interfacial adhesion between UHMWPE particles and GO sheets. The characterizations of POM and SEM proved that good segregated structure was only obtained in DA–GO/UHMWPE or DA–GO/HDPE/UHMWPE composite. Strong interfacial adhesion between fillers and matrix exhibits positive effect on gas barrier property. Compared to the GO/UHMWPE composite film, dramatic decrease in O2 permeability coefficient by 42.2 and 48.1%, from 15.4 × 10−14 to 8.9 × 10−14 and 8.0 × 10−14 cm3 cm cm−2 s−1 Pa−1, is achieved upon the addition of only 0.5 wt% fillers, respectively. The DSC results demonstrated that the enhanced gas barrier performance was ascribed to the strong interfacial adhesion between DA–GO/HDPE and UHWMPE matrix, rather than the crystallinity of UHWMPE matrix. Additionally, the decrease in UHMWPE particle size might be conducive to improving the gas barrier property of composite films due to the formation of more isolation layers perpendicular to the film plane.

The reinforcing mechanism study of carbon nanotube in the NR matrix

The reinforcement mechanism of CNT in rubber matrix is an important and interesting subject. In this paper, carboxyled multi-walled carbon nanotubes (CNT) were used to prepare natural rubber (NR) nanocomposites (CNT/NR). CNT/NR composites were formed by mechanical blending method and the properties such as tensile strength, tensile modulus, tear strength, elongation at break and hardness were studied. The results of Mechanical property show that the physical property of NR filled with 9 phr CNT (CNT/NR-9) is similar to that with 30 phr carbon black (CB) (CB/NR-30). In addition, the dispersion and interaction between CNT and NR were also studied by scanning electron microscope, transmission electron microscope, dynamic mechanical testing system and bound-rubber analysis. According to the results, CNT is considered to exhibit random orientations and form “string bag” structure in rubber matrix and the reinforcement mechanism of CNT is different to that of CB.

Toughness Reinforcement in Carbon Nanotube-Filled High Impact Polypropylene Copolymer with β-Nucleating Agent

In this work, carbon nanotubes (CNTs) were introduced into an impact polypropylene copolymer (IPC) with β-nucleating agent to prepare IPC composites just by means of a simple mechanical blending method without any special treatment of the CNTs. The resultant IPC composites demonstrated an impressively improved impact property (97.78% increment of toughness compared to pure IPC). It was found that CNT aggregates were dispersed in the polypropylene homopolymer (hPP) matrix rather than the interface between the dispersed phase and hPP host. At the presence of CNTs, the size of the ethylene–propylene random copolymer elastomer particles in the IPC nanocomposites was decreased as evidenced by scanning electronic microscopy, and moreover, the mobility of molecular chains in the amorphous phase of the hPP matrix and crystalline lamellae was enhanced as confirmed by dynamic mechanical analysis and small-angle X-ray scattering measurement. The selective distribution of CNTs, the decreased size of elastomer particl...

Research on the damping properties of Fe12O19Sr/the polyurethane elastomer composite

Magnetic elastomer composite is a promising damping material. In this paper, both strontium ferrite (Fe12O19Sr) powders and polyurethane elastomer which were mixed by mechanical blending method were used as the magnetic filler and as the matrix respectively, the properties of the magnetic damping composite materials were studied. The results show that the magnetic properties of the magnetic elastomers composite are enhanced with the ferrite loading. The mechanical properties and Shore hardness are highly influenced by mass fraction of ferrite particles. The damping properties of magnetic elastomer composite reach best when the strontium ferrite loading is 15phr, and the damping properties deteriorate when the loading continue increasing. The damping properties of the composites with the X direction of magnetization are better than that with Y direction of magnetization.

Retained ratio of reinforcement in SAC305 composite solder joints: effect of reinforcement type, processing and reflow cycle

Purpose This paper aims to systematically study the effect of reinforcement type, processing methods and reflow cycle on actual retained ratio of foreign reinforcement added in solder joints. Design/methodology/approach Two kinds of composite solders based on SAC305 (wt.%) alloys with reinforcements of 1 wt.% Ni and 1 wt.% TiC nano-particles were produced using powder metallurgy and mechanical blending method. The morphology of prepared composite solder powder and solder pastes was examined; retained ratios of reinforcement (RRoR) added in solder joints after different reflow cycles were analysed quantitatively using an Inductively Coupled Plasma optical system (ICP-OES Varian-720). The existence forms of reinforcement added in solder alloys during different processing stages were studied using scanning electron microscope, X-ray diffractometry and energy dispersive spectrometry. Findings The obtained experimental results indicated that the RRoR in composite solder joints decreased with the increase in the number of reflow cycles, but a loss ratio diminished gradually. It was also found that the RRoR which could react with the solder alloy were higher than that of the one that are unable to react with the solder. In addition, compared with mechanical blending, the RRoRs in the composite solders prepared using power metallurgy were relatively pronounced. Originality/value Present study offer a preliminary understanding on actual content and existence form of reinforcement added in a reflowed solder joint, which would also provide practical implications for choosing reinforcement and adjusting processing parameters in the manufacture of composite solders.

Preparation of PTFE/graphene nanocomposites by compression moulding and free sintering: A guideline

ABSTRACTThis work was aimed at preparing polytetrafluoroethylene (PTFE) nanocomposites filled with graphene nanoplatelets and investigating how the graphene nanoplatelets and the preparation techniques influenced the physical properties. Graphene was incorporated up to 4 vol % of the total PTFE system by dry and solvent assisted blending. The powder compaction was evaluated using the Kawakita/Ludde model to describe the compressibility of the powder blends. The nanocomposite billets were prepared using cold compression moulding by applying preform pressures between 12.7 and 140 MPa and the preform billets were sintered at 380°C using a specific sintering cycle. The changes in the physical dimensions, billet mass, density, and void content of the billets, pre and post sintering, were analyzed with experimental design to evaluate the influence of the precompaction pressure and graphene loading. From the evaluation it was concluded that the ideal compaction pressure was at 12.7 MPa and the solvent assisted blending was superior to the mechanical blending method. Furthermore, the compression creep tests confirmed the ideal processing temperature and graphene loading range to improve the mechanical properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43369.