Types Of Silane Coupling Agents Research Articles

Facile synthesis of functionalized ionic surfactant templated mesoporous silica for incorporation of poorly water-soluble drug

The present paper reported amino group functionalized anionic surfactant templated mesoporous silica (Amino-AMS) for loading and release of poorly water-soluble drug indomethacin (IMC) and carboxyl group functionalized cationic surfactant templated mesoporous silica (Carboxyl-CMS) for loading and release of poorly water-soluble drug famotidine (FMT). Herein, Amino-AMS and Carboxyl-CMS were facilely synthesized using co-condensation method through two types of silane coupling agent. Amino-AMS was spherical nanoparticles, and Carboxyl-CMS was well-formed spherical nanosphere with a thin layer presented at the edge. Drug loading capacity was obviously enhanced when using Amino-AMS and Carboxyl-CMS as drug carriers due to the stronger hydrogen bonding force formed between surface modified carrier and drug. Amino-AMS and Carboxyl-CMS had the ability to transform crystalline state of loaded drug from crystalline phase to amorphous phase. Therefore, IMC loaded Amino-AMS presented obviously faster release than IMC because amorphous phase of IMC favored its dissolution. The application of asymmetric membrane capsule delayed FMT release significantly, and Carboxyl-CMS favored sustained release of FMT due to its long mesoporous channels and strong interaction formed between its carboxyl group and amino group of FMT.

Preparation and Physical Properties of Poly(lactic acid) Bio-Composites using Surface Modified Microfibriled Celluloses

The surface modification of microfibriled cellulose (MFC) was carried out through the hydrolysis-condensation reaction using (3-aminopropyl)triethoxysilane (APS) and 3-glycidyloxypropyltriethoxysilane (GPS) and then the modified cellulose was compounded with bio-degradable poly(lactic acid) (PLA). Also, pristine MFC was compounded with PLA as a control groups. The confirmation of surface modification for the pristine MFC was characterized by FT-IR and SEM/EDX. The thermal and mechanical properties of the PLA/MFC composites depended on the content of MFC and the type of silane coupling agents. From the thermal, morphological and mechanical behaviors of the PLA/MFC composites, it was found that GPS-MFC was more successful to improve the interface adhesion between PLA matrix and the surface of MFC than that of APS-MFC.

Effect of silane coupling agent on the mechanical properties of nitrile butadiene rubber (NBR)/organophilic montmorillonite (OMMT) nanocomposites

Abstract The effect of coupling agents on the mechanical properties of nitrile butadiene rubber (NBR)/organophilic montmorillonite (OMMT) clay nanocomposites was studied using three different types of silane coupling agents, which were γ-(aminopropyl)triethoxysilane, γ-(mercaptopropyl) triethoxy silane, and bis-[(γ-triethoxy silane)proply] tetrasulfur. The NBR/OMMT nanocomposites were prepared via the melt compounding with OMMT clay. The effect of silane coupling agents on the dispersion of OMMT in the polymer matrix was studied by X-ray diffraction. Dynamic mechanical analysis was employed to investigate the mechanical properties change induced by the silane coupling agents. The results suggest improved mechanical properties for the nanocomposites with coupling agents of γ-(mercaptopropyl) triethoxy silane and bis-[(γ-triethoxy silane)proply] tetrasulfur, whereas reduced mechanical properties were observed for nanocomposites with γ-(aminopropyl)triethoxysilane.

Comparison of coupling effectiveness among amino-, chloro-, and mercapto silanes in chloroprene rubber

Organoalkoxysilane was grafted onto the surface of precipitated silica (PSi), and the modified PSi was characterized by particle size analysis, DRIFT and 29Si NMR spectroscopy. There were 3 types of organoalkoxysilane used in this work, namely, 3-aminopropyl triethoxysilane (APTES), 3-chloropropyl triethoxysilane (CPTES) and bis (3-triethoxysilylpropyl) tetrasulfide (TESPT). The magnitude of the Payne effect, bound rubber content and mechanical properties of chloroprene rubber (CR) filled with unmodified and silane-modified PSi were investigated. Results reveal that the type of silane coupling agent (SCA) affects not only compound processability, but also mechanical properties of the CR vulcanizates. Among the 3 SCAs, it is evident that APTES and TESPT are capable of reducing the filler-filler interaction more efficiently than CPTES, as evidenced by Payne effect results, leading to superior compound processability. Mechanical properties of the CR vulcanizates filled with APTES-modified and TESPT-modified PSi are also greater than those filled with CPTES-modified PSi. This might be ascribed to the combined effects of enhanced rubber-filler interaction and improved filler dispersion.

유-무기 하이브리드 코팅 용액을 이용한 고굴절 하드코팅 막의 제조

출발물질인 TTIP로부터 이산화티탄 졸을 합성하여 무기물로 사용하고 유기물로서 실란커플링제인 methacryloxypropyl trimethoxysilane (MPTMS), aminopropyl triethoxysilane (APS), glycidoxypropyl trimethoxysilane (GPTMS), vinyltriethoxysilane (VTES)을 2종 혹은 3종씩 복합 사용하여 유-무기 하이브리드 코팅 용액을 제조하였다. 그 후 코팅 용액을 기재인 PC시트 위에 스핀 코팅시키고, 열경화 시켜 하드코팅 막을 제조하였다. 2종 실란커플링제를 혼합하여 제조된 코팅 막들은 기재와의 부착력과 연필경도가 우수하지 못했으나, 3종 실란커플링제를 혼합하여 제조한 코팅 막은 2H~4H의 향상된 연필경도와 5B의 우수한 부착력을 나타내었다. 이산화티탄 졸의 첨가량이 20 g인 코팅 막의 굴절률은 550 nm에서 1.56을 나타내었으나 이산화티탄 졸의 첨가량을 20 g에서 30 g으로 증가시킨 경우, 코팅 막의 굴절률이 1.63으로 향상되었다. Inorganic-organic hybrid coating solutions were synthesized using titania sol from titanium isopropoxide (TTIP) as an inorganic component and mixture of two or three types of silane coupling agents, such as methacryloxypropyl trimethoxysilane (MPTMS), aminopropyl triethoxysilane (APS), glycidoxypropyl trimethoxysilane (GPTMS) and vinyltriethoxysilane (VTES) as an organic component. The hard coating films were obtained by spin-coating on the polycarbonate sheets and curing the inorganic-organic hybrid coating solutions. The coating films made from the mixture of two types of silane coupling agents showed poor pencil hardness and adhesion, while those from the mixture of three types of silane coupling agents exhibited an improved pencil hardness of 2H~4H and adhesion of 5B. The refractive indexes of coating films were increased from 1.56 to 1.63 at 550 nm by increasing the content of titania sols from 20 to 30 g.

Study of coupling agent modification of cotton stalk bast fibres reinforced polylactic acid flame-retardant composites

In this experiment, cotton stalk bast fibre was modified, respectively, with A–171, KH–550 and TC–114 coupling agent, to improve the mechanical properties of fibre board. After testing the modified fibre board for its mechanical properties and analysing coupled fibre with FT–IR, it is proved that there were some new groups introduced into the fibre. Experimental results showed that adding A–171 and KH–550 type of silane coupling agent improves the mechanics properties of the material increasingly. A–171–type silane coupling agent was better for tensile strength and bending strength of the fibre board, increased by 31 and 65%, respectively, and the notched impact strength of fibre board KH–550 silane coupling agent was larger, and could be increased by 52.2%.

Mechanical and Thermal Properties of Natural Rubber Latex Modified by Purple Carbon Black

Stable aqueous solution of purple carbon black (PCB) was prepared first and then added to prevulcanized natural rubber latex. The effects of the amount of PCB, silane coupling agent and the type of silane coupling agent on the mechanical properties of the vulcanized latex film were researched. The results show that the best mechanical properties were obtained when the vulcanized film was filled with 6 phr PCB modified by KH560. TG shows that thermal stability of the film with PCB modified by KH560 increased. DSC shows that the glass transition temperature of the film increased after adding PCB.

Comparison of Coupling Effectiveness among Amino-, Chloro-, and Mercapto Silanes in Chloroprene Rubber

The present work focuses mainly on the uses of silane coupling agents in chloroprene rubber (CR) reinforced with precipitated silica (PSi). Grafting of organoalkoxysilane onto surfaces of PSi was conducted, and the characteristics of surface-modified PSi were determined by BET technique, light-scattering particle size analysis, DRIFT and 29Si NMR spectroscopy. The 3 types of silane coupling agents used in this work were as follows: 3-aminopropyl triethoxysilane (APTES), 3-chloropropyl triethoxysilane (CPTES) and bis (3-triethoxysilylpropyl) tetrasulfide (TESPT). Processability of compounds and mechanical properties of vulcanizates were then investigated, and compared for the effectiveness of silane coupling agents used in property enhancement. The results reveal that the silane type affects not only the compound processability, but also the vulcanizate mechanical properties. Among 3 silanes, the CPTES and TESPT are capable of reducing the filler-filler interaction to greater extent than the APTES, leading to superior compound processability. Moreover, the amino and mercapto groups of APTES and TESPT, respectively, significantly enhance the mechanical properties of CR vulcanizate more effectively than the chloro groups of CPTES. This might be ascribed to the combined effects of enhanced rubber-filler interaction and improved filler dispersion.

Improvement of adhesive strength of segmented polyurethane on Ti–29Nb–13Ta–4.6Zr alloy through H2O2 treatment for biomedical applications

The number of hydroxyl groups on a Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy surface was controlled through H₂O₂ treatment for further improvement of the adhesive strength and durability against water of TNTZ/silane layers (SILs)/segmented polyurethane (SPU) composites. The effect of the terminal functional groups on the adhesive strength of SPU on TNTZ, and the adhesiveness of SPU on TNTZ against water was investigated. Three types of silane-coupling agents were used to bind TNTZ and SPU: methacryloxypropyltrimethoxysilane (γ-MPTS), aminopropyltriethoxysilane (APS), and mercaptopropyltrimethoxysilane (γ-MPS). The adhesive strength of each composite was evaluated by shear bonding tests. The number of hydroxyl groups increases with an increase in treatment time at a H₂O₂ concentration of 5% (v/v). On the other hand, an increase from 5% (v/v) to 30% (v/v) in H₂O₂ concentration leads to a decrease in the number of hydroxyl groups on the TNTZ surface because at higher H₂O₂ concentrations, the reaction that consumes the hydroxyl groups is dominant. The shear bonding strength is doubled compared with the untreated TNTZ/SIL/SPU interface. Although the shear bonding strength decreases after immersion in water for 30 days when APS and γ-MPS are used, TNTZ/γ-MPTS/SPU composites exhibit good durability to water and maintain an equivalent shear bonding strength before immersion in water.

Bond strength of a dental leucite-based glass ceramic to a resin cement using different silane coupling agents

AimTo evaluate the effect of different types of novel silane coupling agents with two concentrations on the micro-tensile bond strength of a dental glass ceramic with leucite crystals to a dual-cured resin cement using an optimized method of silane application. MethodsLeucite-reinforced feldspathic ceramic blocks were fabricated, wet ground and cleansed. The bonding ceramic surfaces were treated with different organosilane solutions as follows: Control silane: Monobond S; methacryloxypropyltrimethoxy silane and experimental silanes with two concentrations (1.0 and 2.5vol%): amino, isocyanate, styryl, and acrylate silanes. The silane application method consisted of brush application, hot air drying followed by rinsing with hot water and drying. Then a thin layer of an unfilled resin and a dual-cured resin cement was light-cured on the ceramic surfaces. The resin–ceramic blocks were stored in distilled water at 37°C for 24h and sectioned to produce beam specimens (n=17) with a 1.0mm2 cross-sectional area. Specimens were then subjected to thermocycling and tested in a micro-tensile tester device. Data were analyzed using analysis of variance and Tamhane post-hoc test. ResultsThe mean micro-tensile bond strength value for the styryl silane was significantly higher (P<0.05) than the other types of silanes except for the Monobond S. The mean bond strength values for isocyanate silanes were significantly lower than the other silanes tested (P<0.05). No statistically significant difference in the bond strength between the 1.0 and 2.5vol% of experimental silanes was observed (P>0.05). ConclusionsThe micro-tensile bond strength of the leucite-based dental glass ceramic to a resin cement was affected by the type of silane coupling agent and not by the concentration of silane solutions. The best bond strength overall was achieved by methacryloxypropyltrimethoxysilane and experimental styryl silane solutions.

Effect of organosilane coupling agents on microstructure and properties of nanosilica/epoxy composites

AbstractThree types of silane coupling agents, γ‐aminopropyltriethoxysilane, γ‐glycidoxypropyltrimethoxysilane, and γ‐methacryloxypropyltrimethoxysilane, were used as modifiers to modify the surface of the nanosilica, respectively, and the nanocomposites of the epoxy resin filled with nano‐sized silica modified by three silane coupling agents were prepared by physical blending. The properties of the modified silica nanoparticles were characterized by Fourier transform infrared spectrum and particle‐size analyzer. The microstructure, mechanical behavior, and heat resistant properties of the nanocomposites were investigated by transmission electron microscopy, scanning electron microscopy, thermo gravimetric analyses, differential thermal gravity, differential scanning calorimetry, and flexural tests. The results showed that these modifiers are combined to the surfaces of nanosilica by the covalent bonds, and they change the surface properties of nanosilica. The different structures of coupling agents have different effects on the dispersibility and stability of modified particles in the epoxy matrix. In comparison, the silica nanoparticles modified by γ‐glycidoxypropyltrimethoxysilane exhibit a good dispersivity. The nanocomposites with 4 wt% weight fraction nanosilica modified by γ‐glycidoxypropyltrimethoxysilane have higher thermal decomposing temperature and glass transition temperature than those of the other two composites with the same nanosilica contents, and they are raised by 43.8 and 8°C relative to the unmodified composites, respectively. The modified silica nanoparticles have good reinforcing and toughening effect on the epoxy matrix. The ultimate flexural strengths of the composites with 4 wt% nanoparticles modified by γ‐aminopropyltriethoxysilane, γ‐glycidoxypropyltrimethoxysilane, and γ‐methacryloxypropyltrimethoxysilane are increased by 10, 30, and 8% relative to the unmodified composites, respectively. The flexural fracture surfaces of modified composites present ductile fracture features. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers

Effect of coupling agents on thermal, flow, and adhesion properties of epoxy/silica compounds for capillary underfill applications

Abstract In this study, the different silane coupling agents were added to epoxy/silica systems. The effects of the type of silane coupling agent in the epoxy/silica compounds on the thermal, flow and adhesion properties were investigated. The curing behavior was examined by differential scanning calorimetry (DSC), and the flow properties of the epoxy compounds were evaluated from penetration rate measurements. The adhesion strength as a mechanical property was determined by die shear strength testing. The silane coupling agent type had a significant effect on the thermal, flow and adhesion properties. The coefficients of thermal expansion (CTE) and adhesion of the DGEBF epoxy/SiO 2 systems could be enhanced by the addition of silane coupling agents. In addition, the penetration rate was increased by the addition of a coupling agent except for the CA-A coupling agent. This was interpreted in terms of the reactive functional groups and dispersion forces resulting in coupling agents on the interfaces between the DGEBF epoxy resin and silica.

Glass fiber reinforced ROMP-based bio-renewable polymers: Enhancement of the interface with silane coupling agents

In this study, the influence of silane coupling agents on interfacial adhesion in glass fiber reinforced polymers from the ring-opening metathesis polymerization (ROMP) of a linseed oil-based monomer and dicyclopentadiene is investigated experimentally. Two types of silane coupling agents, norbornenylethyldimethylchlorosilane (MCS) and norbornenylethyltrichlorosilane (TCS), are examined. Interfacial shear strength (IFSS) is evaluated by the microbond technique. The IFSS increases by about 150% for the MCS-treated fibers and by about 50% for the TCS-treated fibers compared to untreated fibers. Dynamic mechanical analysis of composite panels made with untreated and silane-treated fibers reveals that MCS-treated fiber composites have the highest storage modulus and glass transition temperature, indicating strong interfacial interactions at the glass/matrix interface. Short beam shear tests and scanning electron microscopy of fracture surfaces also confirm that MCS is more effective than TCS at improving interfacial adhesion.

Thermal Conductivity and Mechanical Properties of Wood Sawdust/Polycarbonate Composites

Wood sawdust was increasingly being used as reinforcement in commercial thermoplastics due to low cost, reusable raw materials. One of the problems of using wood sawdust is its interfacial adhesion with polymeric matrix. In this research, two types of silane coupling agents (N-(3-Trimethoxysilylpropyl) diethyllenetriamine and γ-aminopropyl trimethoxy silane) and sodium hydroxide were used for the modification of interfacial adhesion in wood sawdust/polycarbonate composites. The effects of chemical treatment and wood sawdust content (10, 20 and 30 % by wt) were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), thermal conductivity analysis. Youngs modulus of composites was in general higher than the neat PC except for the one with γ-aminopropyl trimethoxy silane treatment. Tensile modulus of composites was increased as the filler loading increased. Nevertheless, the addition of wood sawdust resulted in the tensile strength reduction of the composites. The SEM micrographs reveal that the aggregation of wood particles and weak interfacial bond between the treated wood sawdust and the polymeric matrix with increasing filler loading. Furthermore, the thermal conductivity was reduced significantly with the increment of wood sawdust contents.

Surface‐activated nanosilica treated with silane coupling agents/polypropylene composites: Mechanical, morphological, and thermal studies

AbstractThis work reports the mechanical, morphological, and thermal properties of the polypropylene (PP) nanocomposites containing nanosilica (nano‐SiO2) which were treated by different functional group silane coupling agents. Four types of silane coupling agents namely aminopropyltriethoxy silane (APTES), glycidyloxypropyltrimethoxy silane (GPTMS), trimethoxysilylpropyl methacrylate (TMPM), and dichlorodimethyl silane (DCMS) were used to modify the surface‐activated nanosilica. To enhance the effectiveness of the coupling, nanosilica was chemically activated and analyzed through FTIR and X‐ray photo electron spectroscopy (XPS). The highest tensile strength was recorded by the activated nanocomposites treated with APTES followed by nanocomposite treated with GPTMS, TMPM, and DCMS, respectively. The addition of silane coupling agents into nano‐SiO2/PP system further improved the tensile modulus of the PP nanocomposites. From the transmission electron microscopy (TEM) analysis, activated nanosilica treated with APTES showed better nanosilica dispersion in the PP matrix and lesser agglomeration occurred when compared with the other silane coupling agents which were used in this study. Surface activation process does not effectively increase the degree of crystallinity and thermal stability on the PP nanocomposites. However, with the assistance of the surface treatment, it was found that the thermal behavior of the PP nanocomposites had been enhanced. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

Cellulose acetate/polysilsesquioxane composites: Thermal properties and morphological characterization by electron spectroscopy imaging

AbstractCellulose acetate (CA) composites using two types of silane coupling agents (methyltrimethoxysilane and phenyltriethoxysilane) were prepared through two methodologies: direct reaction between CA and the specific monomer and reaction of CA with oligomers, which were produced by prehydrolysis of the same monomers. The thermal behavior and morphology of the materials were studied. The composites showed thermal stability similar to pure CA, increase of residue content at 790°C and reduction in the glass transition temperature. Complementary microscopy techniques were applied to investigate the distribution of polysilsesquioxane in the CA matrix. Silicon mapping images showed the presence of domains with higher polysilsesquioxane concentration than the matrix and also the presence of silicon‐rich nanodomains dispersed throughout the matrix. Based on mapping characterization, a schematic representation of the CA/polysilsesquioxane composite morphology was proposed. The organosilane type and architecture influenced the thermal behavior and the morphology of these materials. The results suggest that the silane coupling agents could be used to produce CA films with a range of properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

실란커플링제 종류 변화가 수분산 폴리우레탄의 특성에 미치는 영향

NCO terminated polyurethane prepolymers were synthesized from isophorone diisocyanate(IPDI), poly (tetramethylene glycol)(PTMG) and dimethylol propionic acid(DMPA). Subsequently, waterborne polyurethanes were prepared by capping the NCO groups of polyurethane prepolymers with different types of silane coupling agents, such as methyltrimethoxysilane(MTMS), glycidoxypropyl trimethoxysilane(GPTMS), methacryloxypropyl trimethoxysilane (MPTMS) and aminopropyl triethoxysilane(APS). The average particle size of the waterborne polyurethane solutions was increased by adding silane coupling agents. Also, the coating films prepared from GPTMS, MPTMS and APS, exhibited better pencil hardness than those from pure waterborne polyurethane. On the other hand, the coating films from MTMS did not show an improved pencil hardness than those from pure waterborne polyurethane.

Interfacial Optimization of Acetate Taffeta Fabric/PLA Composites

For the interfacial optimization of Acetate Taffeta Fabric (ATF) with Poly Lactic Acid (PLA), steady-state uniform atmospheric glow discharge (AGD) and Silane treatments were studied, respectively. In AGD, the plasma polymerization time for ATF was varied up to 3 minutes. In silane treatments, three types of silane coupling agents, aminoethylaminopropyl-trimethoxysilane, 3-glycidoxypropyl-trimethoxysilane and 3-methacryloxypropyltrime-thoxysilane, were used respectively with concentrations ranging from 0 to 5%. Silane coupling agent was chosen since -OH in silane always reacts with -OH in PLA. Also, all three silanes have similar chemical structures with that of Lactic Acid. The sizing on the fabric was with a solution containing PVA, acryl and water at the ratio of 3:1:96. Peel tests were carried out for the surface modified fabrics before and after removing the sizing. Highest peel test results was obtained with 3% silane concentration. Tensile tests were carried out before analyzing the fracture surface of the composites by scanning electron microscope. Compared to raw fabric, plasma and silane treatments have improved the tensile strength at maximum of 30.4 and 27.4%, respectively.

Effect of Silanes on Mechanical and Thermal Properties of Silicone Rubber/EPDM Blends

The effect of four types of silane coupling agents on the mechanical and thermal properties of silicone rubber and ethylene–propylene–diene monomer (M-class) rubber (EPDM) blends is studied, namely, isobutyltriethoxysilane (BUS), acryloxypropyltriethoxysilane (ACS), aminopropyltriethoxysilane (AMS), and vinyltriethoxysilane (VIS). ACS and VIS increase the crosslink density of the blends, which results in higher tensile strength, modulus, and thermal stability, but lower elongation at break compared with the other silanes. However, the blend containing BUS shows highest tanδ in the temperature range of 45°C to 200°C. Thermogravimetric analysis shows two steps of degradation for all the samples, but little difference with the varied silanes.

Effect of flyash content, particle size of flyash, and type of silane coupling agents on the properties of recycled poly(ethylene terephthalate)/flyash composites

AbstractRecent time's polymer waste disposal is a challenging task as the quantity of polymer waste is increasing day by day. Here particulate composites have been developed from recycled poly(ethylene terephthalate) filled with flyash. Flyash of different particle sizes have been used, and effect of particle size and flyash content on the mechanical properties of composites has been analyzed. Tensile and flexural properties of the composites are found to increase with increase in filler content up to 15% and after that decreases due to the agglomeration of flyash particles. SEM studies also showed good dispersion at lower loadings. The use of silane coupling agents was found to increase the flyash/WPET interaction there by increase in mechanical properties is observed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011